Thread that perished: >>2981579>I'm new to electronics. Where to get started?It is an art/science of applying principles to requirements.Find problem, learn principles, design and verify solution, build, test, post results, repeat.Read the datasheet.>OP source:https://github.com/74HC14/ohmOPbake at page 10, post in old thread>Comprehensive list of electronics resources:https://github.com/kitspace/awesome-electronics>Project ideas:https://hackaday.iohttps://instructables.com/tag/type-id/category-technology/https://adafruit.comhttps://makezine.com/category/electronics/>Books:https://libgen.is/>Principles (by increasing skill level):Mims III, Getting Started in ElectronicsGeier, How to Diagnose & Fix Everything ElectronicKybett & Boysen, All New Electronics Self-Teaching GuideScherz & Monk, Practical Electronics for InventorsHorowitz and Hill, The Art of Electronics>Recommended software tools:KiCAD 6+CircuitmakerLogisim Evolution>Recommended Components/equipment:OctopartLCSCeBay/AliExpress sellers, for component assortments/sample kits (caveat emptor)Local independent electronics distributorsladyada.net/library/procure/hobbyist.html>Most relevant YouTube channels:W2AEWMoritz Klein>microcontroller specific problems?>>>/diy/mcg>I have junk, what do?Shitcan it>consumer product support or PC building?>>>/g/>household/premises wiring?More rules-driven than engineering, try /qtddtot/ or sparky general first>antigravity and/or overunity?Go away
>>2989599>suspiciously placed huge walnut with an eye in the middle
I saw a guy 3D print normal plastic with the traces of a PCB layout embossed into it. He then stuck down copper foil/tape and sanded off the high-spots, leaving just the embossed traces. Soldering it would definitely soften the plastic, but if you do it quickly it shouldn’t be an issue even with PLA.But the best way is definitely a fibre laser. They can punch holes through the FR-4 that are charred, allowing you to electroplate them with copper. I think dual-colour lasers can also make un-charred holes and slots and edge cuts using an ultraviolet or blue laser, but I’m not sure. Blue is definitely better for cutting through copper than IR.
>>2989609>huge walnutlooks regular-sized to me. wtf are pogo pins for?also, anyone noticed a fuckup?
>>2989623Pogo pins connect to the antenna, the thin metallic thing stuck to the inside of the shell. Obviously not a big deal considering it worked without the lid on.Maybe some smoke started quickly offgassing when the last of the batts were soldered on? Hard to say.
>>2989624Shorted the batteries with his tweezers turned the tip red hot.
>>2989610>even with PLADoubt, but maybe with a lot of flux and high temperature one can do it.
>>2989674It takes like 5 seconds max to make a joint to a non-power component. Even if the plastic under the component melts, if you don't deform it it won't be an issue, and it won't heat up enough to impact the structure of the whole board. Unless you're making 10x10mm mini boards. Making your board like 3mm+ thick probably helps.You can always anneal your PLA.
>>2989599>Where to get started?Babby's first circuit.
>>2989690>Babby's first circuit.
>>2989676Pla is half-step up from hot melt glue… it melts in your car.The whole premise is ridiculous.Real PCB material is probably cheaper than the pla.
>>2989624>antennaahhhh, right! ty.>>2989628>Shorted the batteries with his tweezers turned the tip red hot.yep. space is so cramped that when he released the pressure on the tweezers, he ended up shorting positive to the ground.wtf do you even find lipo cells this small? in vapes or some shti like that? I think I've seen a vape battery in a video someone did and they looked bigger tho...
>>2989706If you anneal it, the heat deflection temperature goes up past ABS or even polycarbonate, to 150C or so. To anneal something flat, just turn your bed up to 100C after it’s printed and chuck a towel over it for an hour. If you’ve ever tried to plastically weld with a soldering iron, you’ll have a good idea of how poor a thermal conductor plastics are, only a few millimetres around your iron tip gets molten. If thats beneath a layer of copper, then it will hold its shape.Fibreglass FR4 can’t be 3D printed, so its cost is moot when discussing this method of prototyping. You could print a negative then apply a thermoset resin like epoxy, maybe with fibreglass, and do the same technique on that instead. But epoxy is definitely more expensive per kilogram than PLA.
>>2989720>watching some man from africa read a chatgpt scriptishygddt
>>2989728sounds like you watched it, senpai
>>2989720nigger
>>2989725> PLAIs literal waste from making greek yogurt, they didn’t know what to do with all the lactic acid from the processes until 3D printing came along.
>>2989745Pretty sure it’s corn/maize derived. Biodegradable if you own a 50C+ bioreactor!
>>2989745>Is literal waste from making greek yogurtHey! They could mix it with some fluoride (waste from steel making) and put it in our toothpaste.
>>2989747> Biodegradable if you own a 50C+ bioreactor!No, 50 deg C won’t do it any longer… I’ve been tempering it my PLA. Over and over. So now it’s harder than a diamond, denser than osmium, and melts 5 times higher than tungsten.Actually, I’m thinking I can make PCBs from Turds if I temper them….I can’t afford a $2 phenolic FR2 PCB after I bought a $3000 printer and a $1500 PLA drier, and a PLA subscription service. I’m glad I can eat the PLA though… thanks for letting me know.
Do I recall correctly that surface mount electrolytic capacitors are difficult to hand-solder? I made my layout with thru-hole ones instead. I need a 1 uF bipolar capacitor to remove the DC offset from an audio signal and I've heard that ceramics have "microphonics".Also does anyone know a good SMT equivalent of the 1N4148 diode? I found one with a SOD-523 package but I think that might be a bit on the small side, all my other components are 0805.
>>298973010 seconds of it, Big Chaks.
>>2989757>capacitorsWhat's the cap doing? Doesn't look like it's a cap to ground, for any series caps in an audio circuit I'd want to use film caps. Though if it's under constant DC bias, an electrolytic isn't the end of the world, they can actually be pretty low leakage if you overspec their voltage rating. Polymer electrolyte caps should be better than conventional liquid electrolyte caps by any relevant metric.>a good SMT equivalent of the 1N4148 diode?1N4148W is what I'd go with. The WS is a small and somewhat delicate SOD-323 package (still larger than a SOD-523), but the W is in a larger SOD-123. There's also always MELFs, which are bigger still. Pic related shows MELF, 123, 323, 523.
>>2989780
Question for /ohm/: is there any money in electronics repair? Do people even look to repair stuff in 2026? Can you even make a living wage with it?
>>2989790Yes, but it seems tough. I know a guy that specialises in television and home audio, he does both home-call installation and repair. So I guess he's already effectively filtering for whate repairs are and aren't worth attempting. Because of the labour cost, you can only really effectively repair things that are sufficiently valuable. If that's new electronics, then it's often difficult to repair thanks to tiny SMDs, custom programmed MCUs and ASICs, and proprietary software tools. You might have a chance with those for items popular enough to heve been reverse-engineered, like smartphones, but microsoldering doesn't seem very appealing.The market I'd aim for is analogue audio, especially vintage stuff but not only. Recapping amps and crossovers is easy on the eyes and the hands, while you're at it you can sell them bluetooth receivers and pre-terminated speaker cables. The harder fixes are still relatively easy to troubleshoot, by measuring Vbe and bias currents and such, and with repeating audio signals it's pretty easy to use even the shittiest scope. Even newer stuff can be pretty easy to work on, unless it's class-D or some sort of fancy multimedia HDMI amp.I volunteer locally with a "repair cafe" once a month, there's definitely a lot of people out there looking to get broken things fixed. But not many people willing to pay a lot for that. If you can replace a micro-USB socket in a bluetooth speaker in ten minutes, maybe it's worth it. But more often than not it takes half an hour just to take it apart.
Is easyeda stealing all my data?
>>2989780>>2989781Thanks, the MELF package looks like what I want, in fact I had some in a smt "practice kit" but didn't know what they were called.The circuit has 3 caps in series at various places to remove DC bias that is introduced from OTAs, or to centre my waveform around 0 V after applying a DC offset. I think it's important to remove the DC around the filter feedback loop.To be honest, this is not high-fidelity audio, just square and sawtooth waves, and I wonder if film caps would be overkill. I'm just using basic bipolar aluminium electrolytics on my breadboard which are about 1/8th the cost of the equivalent film cap. Easiest of all would be a smt ceramic cap but I've heard that it's "conventional wisdom" not to use them to decouple audio.
>>2989797>The market I'd aim for is analogue audio, especially vintage stuff but not onlyInteresting. Thanks! I guess that makes sense.I was hoping for some computer stuff since I know a lot more about it.>But not many people willing to pay a lot for that. If you can replace a micro-USB socket in a bluetooth speaker in ten minutes, maybe it's worth it. But more often than not it takes half an hour just to take it apart.Yeah, 90% of things are unprofitable since the replacement is cheaper than the time it takes to open and diagnose something. Items that have nostalgia and sentimental value are the only things people are willing to pay to have them repaired.
>>2989812Yeah I’d just use electrolytic caps, probably 50V rated or more. Though in your case it looks like biases will be going positive and negative, so you’ll want to consider bipolar electrolytic caps.
>>2989856Out of interest I tried swapping my 1 uF bipolar aluminium electrolytics with 220 nF polypropylene film capacitors. Now my square wave slopes downwards, but it still sounds the same. I'll probably stick with the electrolytics.
>>2989867this is with the 1 uFresonance is looking nice :^)
>>2989720Youtube is so cancerous right now, how they manage to get people to listen is beyond me.
I aligned everything to the grid this time (sort of) and used a consistent trace width. I feel like the layout could be more compact, but it still comfortably fits within the 10x10cm square that seems to be some price break point at JLCPCB
>>2989890Gonna cram in some pin headers for input/output connectivity? Both for power and signals.Also looks like a few of those blue traces could be a bit shorter, and some of the pads and vias could be spaced a bit more from nearby traces for clearance reasons. I also like to ensure vias of different nets (and any traces or footprints on the reverse layer really) are spaced apart from one another, such that the ground fill can get between them. You could also thicken up the power traces if you want, but nots not a big deal for this kind of circuit.You can also use Mitxela’s PCB trace melting KiCAD plug-in if you want to make your boards look cooler.
>>2989894Yes this is about 95% done, I'll connect the pin header tomorrow. I know I should try and fit as much as possible on the top plane, so is it fair to say that the *number* of vias isn't so important, but I should optimize to minimize the length of traces on the lower layer?Once I am satisfied with the connectivity, I'll turn grid snapping off to space out the traces a bit more nicely. Good pointer about the ground fill.I'm a bit annoyed I have to waste an entire half of a dual flip-flop IC to make my frequency divider, but the single flip flop I ordered turned out to have much faster edge transition requirements than the rest of my circuit can provide. Maybe I could wire it up as a second frequency divider, to provide a sub-sub-octave....
>>2989900>Maybe I could wire it up as a second frequency divider, to provide a sub-sub-octave....I'd just wire it up with pads to solder wires onto, and a pull-down resistor or jumper on each input if needed. That way you can wire it up to whatever you want if you ever need to.
>>2989599i want to build a dtmf tone generator to revive a rotary dial phone without janky ass microcontrollers doing shenanigans and use a tp5088n tone generator chip, i got everything figured out except interfacing the chip with the actual phone line, the datasheet gives this very simplistic schematic, would this actually work? wouldnt the dc current of the phone line fry the transformer? for the ringing ac im not concerned since i want to place this thing after the on/off hook switch
>>2989936Maybe the transformer has a high enough ESR to handle continuous DC?
>>2989599why haven't IC manufacturers capitalized on photovoltaic inverter ICs the way they have with SMPS ICs? you can find hundreds of different ICs for buck converters, boost converters, flyback converters, full bridge converters, etc. but it seems solar is always done with an MCU.
>>2989936>wouldnt the dc current of the phone line fry the transformer?of course notyou'd use a 600:600 ohm transformer which is the load that a typical phone puts on the linehowever, you def need a hook switch or else the phone is forever busylike every asian tranny hookerbut i'd suggest stuffing in a portable miniature secretary phone instead, as it has all the circuitry and buttons already
>>2989941ill order the thing from aliexpress and hook it up, at worst i'll fry my modem
>>2989938Because a proper MPPT algorithm is a looping process. Measure voltage and current, multiply them together, and vary the duty-cycle until the product is maximised. Even without the seeking logic, multiplication like that is a pain to do analog.I’ve seen some cheap mock-MPPT ICs, where you program in a maximum power voltage via resistive divider, and its feedback loop attempts to keep that constant. Might be 5% less efficient than a proper MPPT algorithm, but it’s much simpler and cheaper. It was a Chinese brand chip like this that I used.
finished routing and attached the edge connector. I think this is looking better than my previous attempts. Tried to keep the jumps on the bottom layer as short as possible, it will otherwise be ground, +/- 12 V and +5 V
>>2989999I more or less didn't bother with ground fill on the top layer because there are so many traces that I end up with a lot of isolated areas. The back ground plane is fairly unbroken, thoughthanks for reading my blog
>>2990009Stitching vias. Needs more stitching vias to cover the long traces going to the pin header.
>>2990009>>2990017Yeah I think either a bunch of stitching vias, or at least go out of your way to push the power traces to the very perimeter, like I've done here with the 5V rail. Such that no ground-referenced pads are outside them, ideally no signal traces either. R12, R67, etc. have a pretty roundabout return path.
>>2990009Also C25 is backwards, if it's polarised.
>>2990017>>2990041>>2990042thanks anons, it's useful to be able to run these by people who know what they are doing. I tried harder to route the power traces and I think they break up the ground plane a lot less now?
What is this mystery pin?I spotted a shiny thing on the carpet. It's not from any project of mine. I don't recognize this type of pin at all. It must have fell out of a device or appliance. I have no clue what though. Nothing around the house appears to be malfunctioning.
>>2990128NEMA connector?
>>2990131Far too small.0.4mm thick13.88mm length2.54mm at the wider part1.41mm at the thinner partNot magnetic at all.
>>2990128>>2990136USB A contact?
>>2990138Looking closer, 2.54mm seems way to wide for that. It still looks like a connector from some sort of plug. Especially given the plating, wear, being non-ferrous, and the indent on the smaller side.
>>2990062Yeah that looks good. C29 looks a bit isolated, but it doesn't matter since the top-side ground-plane connects it to C24. It's not necessary anymore, but if you wanted to, you could run the traces from the pin-header to the THT caps on the top-side of the board, then run bottom-side traces from the THT caps to the rest of the board.
>>2990142I hope it won't matter too much because I just ordered the board, lel. At that point in the board the top layer ground plane leads right back to a ground, pin so I'm hoping it should be fine.The boards were about 50 cents each for 10. I don't know how JLCPCB do it. I suppose they're subsidized by their government as part of a plan to achieve global dominance or something.
Got hired by my friend to do a smart meter lora project for him for several buildings. This is great. I love doing shit like that, plus i can do it literally 10x cheaper than the cheapest commercial solution.All those chinkshit parts i impulsepurchased from ali over the years and never used will finally come in handy. I have such a stock of them i don't even need to buy anything else kek
>>2990179Check the current prices for the things you need to replenish and include/mark up that cost in your invoice.
>>2989599Which button do you need to press to turn on the LED?
>>29902642 or 5
>>2990128I figured it out. It's a placeholder for the analog ground on an HDMI to DVI-D cable.
>>2989757For SMT caps, the lead is on the bottom J-lead. You don't want to tack the edges with an iron. You want the whole lead to be soldered to the board. Best for a hot air station work. See image.
>>2990425Flux and capillarity will cover the whole lead just fine as long as you have enough protruding pad to soak the heatDon't want to heat caps too much
>>2990425>>2990427interesting anon. I'm glad I decided to go with through-hole electrolytics though, they will probably be less painful to work with.Just waiting for all the parts to arrive now......
>>2990062Looks like its coming together nice.Some points I have found for your consideration.1 and 2: No right angles, the board manufacture may or may not have improved etching processes controls in place and its best to design your board to be manufactured from anyone. Etching chemical may pool in the corners and the trace may fail over time. Its just good manufacturing process to eliminate fail points for a process.3. Now that you have used the grid to line up all your components, you can now break-it to line shit up.4. You got the space here. Why are the traces bunched up? Move the bank of resistors north and force yourself here to have the bottom traces for the resistor start going south and fan it out nice.Make it beautiful.
>>2990427One end for SMT caps is typically tied to a ground plane. ISO-fine for one time fix, ISO-not-so-fine for manufacturing.
>>2990432Thanks for the pointers, although I'll have to use them to inform future designs, as this board is already ordered.I was dimly aware of the "90 degree corner etchant trap" concept, but is it really still a consideration in current year? My traces are 0.3 mm.I see that one of those traces in area 4 goes uncomfortably close to a pad, but hopefully I can get away with it.
>>2990435From experience: First prototypes never make the cut for manufacturing. You have more knowledge now then when you started and best practices are best. Hunt down the IPC standard pdf files that have been posted on the net and learn from the process and manufacturing engineers experience from the past to make you a better designer.Are you having a fun time doing this?
>>2990432>Etching chemical may pool in the cornersNever heard of that issue with any fab house, and even my own etched boards don't suffer from it.>>2990434Is roasting an electrolytic cap with hot air ISO-fine?>>2990435In future you can change your design rules to force larger clearances, might make avoiding situations like R34's pad 2 easier. In principle these should be changed to be at least as restrictive as your chosen fab-house, but I've never had any issues relating to fab house clearances.
>>2990437>Is roasting an electrolytic cap with hot air ISO-fine?They are designed for hot air [re]flow ovens.
>>2990436This is only ever going to be a hand-soldered hobby project thing, but it will still make sense to look at the standards for future projects. I guess it is fun - although for one-off circuits, I'm still imagining that strip board and through hole components are my best option. But maybe I am living in the last century.>>29904370.2 mm spacing between that pad and trace, but at least the trace will have the solder mask covering it...............
>>2990439>but at least the trace will have the solder mask covering it...............This is where you need to know your board shops tolerances.This passed my light-cones (eyes) today. Maybe something you would like.https://hackaday.com/2026/05/12/another-gift-to-the-world-from-cern-their-entire-set-of-kicad-libraries/https://gitlab.com/ohwr/cern-kicad-libsLooks like 18k footprints library.
>>2990441Looks like I am in the clear, but I'll tweak my design rules settings anyway for next time.Thanks for the link, 18k footprints sure is a lot.
>>2990441Cmon man, my package manager already takes like 5 minutes to confirm that there are no updates to my footprint, symbol, and 3d libs each.
>>2990442Now what is the tolerances for solder mask registration? Is there a chance the mask maybe offset from the pad that the trace is exposed? I'm not trying to be a dick. These are things for consideration when you manufacture boards. Good manufacturing practices.
>>2990443>5 minutes to confirmSounds like you got five minutes for games now. Your welcome.
>>2990444this is all useful stuff that I wasn't specifically aware of, so thanks. I can't actually find figures on the tolerance for the alignment, so I have decided to believe that it will be fine. Guess I'll find out when they arrive.If it all turns out to be a disaster and that trace and pad somehow get connected, the only consequence is that I lose the use of 1 out of 8 board addresses, no big deal.
>>2990447No thank you. I had to leave a career in contract electronic manufacturing for personal moral reasons. I loved the work. Keep posting I would really like to see the progress.
>>2990425>J-lead.>>2990431If you go down the SMT path, as you should, then definitely go for this type of a cap and not the through hole. If you're doing SMT, a soldering iron should not be your primary soldering tool.When I do SMT, I always use a stencil. I can't even explain how much faster spreading solder with a stencil is vs. a soldering iron. Heck, sometimes it's OK to just squirt some paste out of syringe and spread it that way if you don't have a stencil.Also, oftentimes you don't even need electrolytics and can get away with MLCC or tantalums. tl;dr: if you're doing SMT, everything should be SMT including the electrolytics. That simplifies the BOM, cost, and speeds up assembly.
>>2990520Here is an AI blurb on esr.The ESR values can vary significantly based on the type of capacitor:Capacitor Type Typical ESR RangeCeramic Capacitors 0.01 - 0.1 ΩAluminum Electrolytic Up to several ΩTantalum Capacitors Higher than ceramicsUnderstanding and managing ESR is essential for optimizing the performance and longevity of capacitors in electronic circuits.
>>2990522ESR is not that big of an issue in modern circuits if you know how to avoid oscillation and instability. Modern caps will outlive device's useful lifespan if you know how to manage the temp. Modern caps will easily do 10k hours at max temp. Orders of magnitude at lower operating ranges.MLCCs almost always fail because they were soldered with a soldering iron or the board was flexing too much due to temp changes. The reasons why you'd choose electrolytics over MLCCs or tantalums is the need for ca cap to operate at higher voltages, or you need higher capacitance or want to reduce cost.PS: and don't use AI for this shit. Use your fucking head., Don't outsource thinking to a machine.
So how much should I trust these counterfeit Scyllac capacitors (normally $10k+ each) being sold for $1.50?
>>2990537Even less than the ebay sellers quoting $120 for an m4 mac mini.
>>2990524>device's useful lifespanWe come from a different school of thought. Your being a dick. I don't outsource thinking to AI. I'm just not investing time-energy into replying to you for your shitty attitude.
>>2990576>shitty attitudeSays a guy who using an AI to craft responses and when he's proven wrong, he claims the other guy is being a dick and has a shitty attitude. Your attitude sucks and that's why you know so little.
>>2990520If you’ve got stencils and hot air, you’re probably right. But I think this anon is stuck with a soldering iron, also stencils are kinda expensive. To the point where it’s cheaper to get them to solder the components on for you.>>2990524MLCCs also have a distinct voltage dependence to their capacitance to watch out for. And microphonic behaviour. Electrolytics don’t have that. But you wouldn’t catch me dead using a tant.>>2990576You posted shit about ESR unprompted, nobody asked about ESR in the first place. Why would you go out of your way to do that?
>>2990613>If you’ve got stencils and hot air, you’re probably right. But I think this anon is stuck with a soldering iron, also stencils are kinda expensive. To the point where it’s cheaper to get them to solder the components on for you.NTA but you don't even need hot air. You can do it with a cheap hotplate. I've used a syringe to dispense solder paste onto pads and have placed components with tweezers. Surface tension just pulls all of the components in place and I rarely had bridges or soldering failures.Hot plate element is like $15 (or less) and you need a temp PID controller or even better, an Arduino, so you can program the temperature ramps.Soldering SMD with an iron is not only slow but also damages components.
>>2990615isn't it difficult to get the entire surface to heat up uniformly without hot spots?
>>2990615>cheap hotplateEh, if you're doing SOICs and 0805s and don't have stencils, I think I'd rather use an iron. Hand-dispensed solder paste would be worth considering if it were a bunch of 0402s, or DFNs or other leadless chips. Number of parts is another factor of course.>Hot plate element is like $15 (or less) and you need a temp PID controllerLooked into this myself, those hotplates have a PTC heating element, so an off-the-shelf PID controller won't work very well. PID algorithms assume the input duty-cycle will produce a proportional dT/dt regardless of state temperature, but here that proportionality constant changes significantly as a function of state temperature. I expect you'd end up with a very sluggish system, but it might still be fast enough for normal reflow curves. With an arduino you'd be able to use a PID algorithm followed by a correction equation/lookup table.Even cheaper and easier would be to manually control the temperature with a TRIAC dimmer while watching a thermocouple. Going blindly open-loop probably wouldn't be the end of the world either. Not like manual hot-air reflowing follows a proper cooling curve.>Soldering SMD with an iron is not only slow but also damages componentsSource? Seems like using an iron can be significantly quicker, putting less heat into the components. I can't imagine the thermal expansion/contraction of components is a sufficient factor unless you're somehow blasting heat into the component but not the board. MLCCs seem the most likely to break from thermal stress, but even then they're designed to handle some amount of it. Never had a hand-soldered MLCC break on me in my years of hand-soldering 0805s and 0603s.
>>2990624>isn't it difficult to get the entire surface to heat up uniformly without hot spots?No, they're made to be uniform. You can find pictures of people testing them with a thermal camera.If you want to go third-world, a clothes iron with an arduino can also work. There's so many people showing this method online (YT, Instructables etc).
endless options on AliExpress to burn your house down, it seems.Why on earth do they make USB-powered hot plates, that seems like a lot of juice to pull through a USB connection
>>2990439>at least the trace will have the solder mask covering it.Just FYI, solder mask is incidentally an insulator (bonus!) but is not intended as one and should not be used deliberately as one. Safety standards are explicit about this, but it's best to consider it a general principle even if you're not going to be going through that kind of evaluation.
>>2990643The USB ones I've seen before are very small, 5x5cm sort of thing. On a 65W PD supply that's slow, but not completely unreasonable. Those Alientek ones are bigger (104x64mm), but they can do 140W PD and 200W from DC, and claims 120s heat up time to 260C.I was going to make my own reflow plate, since there is a big price difference between the little PTC hotplates you wire up yourself and those. But taking a closer look, these things solve a lot of the problems that are difficult to solve with a soldering iron and a 3D printer, namely the heat resistant housing. House fires aren't really a risk considering you turn these things on, use them for 5-20 minutes, then turn them off again. Not like a 3D printer that you leave for hours unsupervised. My only problems are as follows:- Lots of them say they're for preheating, and alientek claims many other hotplates only go up to 260C, so may struggle reflowing a board on their own.- Most of the reflow plates look to use simple temperature setting interfaces, which are likely constant temperature regulators, instead of temperature-time curve controllers.- Why do I have to buy two different hotplates for soldering and chemistry, can I not get a 350C hotplate with magnetic stirring?And now I'm back to thinking I should make one or modify one. I guess adding magnetic stirring to a soldering hotplate is easier than the alternative. Assuming the hotplate itself isn't magnetic.
>>2990643>endless options on AliExpress to burn your house down, it seems.They ship tens of thousands of those and how many houses burn down from them?>Why on earth do they make USB-powered hot plates, that seems like a lot of juice to pull through a USB connectionbecause USB-C PD exists and you can do a fair bit with 240W? But yeah, I'd prefer something around 400W.
>>2990712hmmmm>>2990714Even then I've never seen any 56V 5A soldering hardware, only ever 20V/28V 5A or lower.
>>2990643>endless options on AliExpress to burn your house downyou preheating these things then going for a nuggie run?
>>2990633Haha… using an iron for everything was common practice in the 70s and 80s. If we had to put ends on a bunch of phono plugs we’d put them in the steam holes on the bottom of the iron and start tinning.
>>2990585Ya i don't keep the scale for esr in memory by capacitor type. I worked in medicine and engineering without a degree for I am competent.EAT DICK FAGGOT.
You lack comprehension for the post thread.
>>2990712>only go up to 260Cisn't there something to be said for low temperature solder for hobby projects though?Sn42/Bi57.6/Ag0.4 allegedly melts at about 140 Chttps://cpc.farnell.com/chip-quik/ts391lt/solder-paste-low-temp-15g/dp/SD02706
>>2990643I am tempted. Even if it's not very good it will let me recover $20 worth of ICs from other boards that I messed up in the past
>>2990842I’ve used it before, it solders nice. But it’s also somewhat weaker, much less common, and forms very brittle joints when mixed with leaded solder. Also not very useful for existing boards without special flavour solder.
>>2990850I'll have to look up review videos of these. Because they just regulate for a constant temperature, unlike the smarter anemic USB models.
Use case?
>>2990906they can be used to replace Compton valves in older designs
Why is my solder being outright repelled by my iron?>clean ur tipI've used tip cleaner and flux and it hasn't made any difference.
>>2991156>used tip cleaner and fluxcompletely inadequate for the situationto get rid of the black crud, you scrape it with the back side of an x-acto knife, or box cutteras soon as you see a hint of shininess, apply solder to tin itkeep going around until the tip front is all shiny and chrome
>>2991156If a good hard scrub (with something no harder than copper) doesn't bring back a tinnable surface, your plating is probably fucked. But I'd guess it's just too much crud. I find a scrub with a facial tissue or paper-towel (while hot) often works where copper wool doesn't.Citric acid powder might also work, idk.
>>2991156When you get a new tip, tin it and clean it a few times before you use it. Keep it clean while you work, and load the tip with a fresh blob of solder before you turn it off. Only use RMA flux and leaded 60/40 or 63/37 solder with your iron, and keep the iron at a moderate temperature.
>>2991156If the plating is really gone, tip cleaner will not help, and you will need a new tip. Tip cleaner is very aggressive and you should only use it in last-ditch maybe-I-can-rescue-this situations like, well, that black tip that won't take tinning for love or money. If it doesn't work you need a new tip.If you have used plumbing flux on the tip, it can completely destroy the plating. That's just one of many reasons soldering with flux is at least intermediate-level. Because you can choose the wrong flux.
>>2991156>>2991178>keep the iron at a moderate temperatureI would be more explicit and say to keep it at the lowest temperature practicable. Hot tips get eaten by oxidation and burn off flux way too quickly.
>>2991156Scrub off the junk and hope the plating isn't fucked. If the plating is damaged, the tip is effectively dead and it will erode very fast.Always clean the tip properly (use brass wool, NOT steel wool - check with a magnet to test for counterfeits) and keep it tinned to prolong the life. Properly cared for, a tip can last years with daily use.May be worth looking into tip care, they generally don't go bad like that unless you're doing something to damage it. Using overly aggressive fluxes, leaving it untinned (especially at high temperatures), or scraping with something abrasive can all very quickly degrade it.
>>2989599Why is a diode needed on the relay here?
>>2991279To prevent the inductive effect caused by the relay, so the reverse flowing current wont damage the transistor
Does anyone have some suggestions for some projects I could do to improve my my ability?I started an avionics apprenticeship a few months ago and I'm learning but slowly and I need my hand held most of the time. Would like to try and get better on my own but I'm not much of a self starter and don't know where to start.
>>2991290What exactly is it you want to train by making a project?>your ability to design circuit schematics>your ability to lay out circuits on a PCB or protoboard>your ability to solder and assemble circuits>your ability to test and troubleshoot circuitsOr something else?And what fields are you specifically trying to learn, I don't know shit about avionics.Here's some lists of projects:https://github.com/Rocheez/4chan-electronics-challenges/blob/master/list-of-challenges.pnghttps://github.com/74HC14/ohmOP/blob/main/ProjectCategories.mdBut some are "follow the instructions" type challenges, others are "design X from scratch" type challenges, with various stages in between. To some extent, the projects you build can be useful, especially instrumentation projects like a milliohm meter or a capacitor/inductor ring-tester.
>>2991295Well in my job I've gotta make/repair a lot of wiring looms and troubleshoot components/circuits, interpret wiring diagrams.I've got a bit of practice putting together looms now though I'm hardly a pro. Probably learning to understand how they work would be the most useful thing for me.For instance, the other day I was given this device, not sure what you call it but you plugged your headset in and 3 position switch to transmit on intercom and a radio PTT button, and I had to work out what all the wires were doing so I could alter these other ones that had a volume knob instead of the button.Anyway I'll take a look at the projects, thanks. Building useful stuff always appeals to me.
>>2989599how would i do pic related? it doesn't matter if it's edge or level triggered.>CLK is 200 khz, variable duty cycle>OUT gets triggered "on" with high CLK>OUT gets triggered "off" with low CLK (OR) high RST>if OUT is triggered "off" it remains "off" until the next high CLK>RST can be ignored with low CLKthe basic component would be a reset dominant SR latch, where CLK=S and RST=R. but i'm not understanding how to get the RST event to latch OUT "off" until the next positive CLK cycle.
hey guys, I need some help with USB stuffI have a charging dock for my Dualsense, it just needs usb c powerI also recently started using a pi pico 2 W as a dongle for it on my PC (https://github.com/awalol/DS5Dongle), and I would like to be able to "integrate" it with the charging dock, so I could use both from a single usb cable going to the pc.obviously the simple answer is a usb hub, but I wanted to know if I can "tap into" the usb-c connection of the charging dock, since that only uses usb-c for power and not data.if it requires adding a few components and not just wiring, that would be fine too.thanks in advance
>>2991351Just split it off of the charger PCB, or use a type C splitter cable with a type C to micro USB adapter on the Pico. There are other options too.
making an extruder board for my 3D printer.
>>2991389Cool stuff. What’s the motivation behind a custom board?
>>2991402I want to replace the OEM main board with an off the shelf part and making custom CAN tool head board is the least janky way to do it.
Just found rbdimmer.com, they sell a couple of TRIAC dimmer modules that are controlled via UART or I2C, which makes it nice and easy to drive a load without worrying about zero-crossing synchronicity. But the 8A module has awful LV/HV isolation so I’d only ever go for the 4A. Especially good for non-real-time control from a computer or raspberry pi or whatever.
>>2991404What off the shelf part do you need it to work with? Some sort of bed level sensor or accelerometer?
>>2991406I have a Manta m5p with a CM4 I want to install, the SOC the OEM used is barely adequate for the application. the CM4 might have enough UART's to connect everything but I also want to add a few things to the tool head, plus the printer is littered with Chinese STM32 knockoff parts that makes running main line klipper problematic, if the tool head board works out then I'll make a custom CAN load cell board also.
Alright, very cheap and questionably safe AliExpress hot plate is en route, do any anons have recommendations for solder paste for SMT boards? I don't have a stencil made, so I plan to just dispense from a syringe.A buddy recommended the low-melting Sn42/Bi57.6/Ag0.4 but I'm sure there are other factors to consider besides just melting point.If my calculations are correct, then everything here except the Pi will fit on my ~100 x 80 mm board.
>>2991412Oh the printer didn’t originally have a toolhead board. How does your board compare to other toolhead boards?
Ignition control board1/3
>>2991428Ignition control board2/3
>>2991426I'm using the schematic for the EBB36 as a guide so it's an EBB36 in a form factor to fit my printer. https://github.com/bigtreetech/EBB
>>2991429Ignition control board3/3Soviet ICs were used
>>2991428Wow, EPROM in a real project is cool. What kind of work does it do, just timing control?
I really want to buy an oscilloscope but don't want to spend 200-300$ on something I don't know how many times, how often I would useI'm getting into electronics, I want to learn embedded and circuit design as a hobby and not necessarily a job; ESP32 programming, analog audio circuits and processing, repairing things that break at home maybe toodo I hunt for a locally sourced 30eur old analog oscilloscope, or get a digital one? I think I'd get more use out of something I can connect to a PC, to also be able to look at the data more comfortably, collect it and run algorithms and analysis and whatever I'd like, but I don't know if a USB oscilloscope is a good idea, and if a cheap one has the necessary safety features, I don't want to kill both the scope and my PCalso, I'm in EU
>>2991444The downside with analog oscilloscopes is they can only show you repeating signals. Perfectly fine for audio use, but for microcontroller stuff that's pretty limiting. Some later/fancier CRT scopes have an ADC and the ability to swap into digital storage mode, mine does this but only stores a hundred or two samples, and these tend to be a bit more expensive. Also my CRT scope is way out of calibration, and it's only drifting more with time.You could get an alibay USB logic analyser as well as an analog scope, that will cover 90% of use-cases. The analog scope will show you discrete voltage levels on repeating audio signals and such,, while the logic analyser can sample non-repeating digital communications, and even decode their protocols for you. I've got a NanoDLA, it's pretty good. There's a cheaper one that also worked fine for me 99% of the time, but it could be a little strange to get connected, and apparently on Windows there's the possibility of a driver or firmware update bricking them.But that remaining 10% is non-repeating analog events, like inrush current surges and testing components to failure.A USB scope is definitely an option, I'd browse the EEVblog forum to see reviews of different models. If you're worried about damaging your computer with one, you can buy USB isolator dongles for $10 or so that should prevent computer damage. Same goes for the logic analyser.My biggest problem with USB scopes, the few times I've tried to use them, is the user interface on the computer itself. Dragging the mouse around on the screen to move dials and knobs, it can be cumbersome. And rando chinese software is never too reliable or full-featured. I'd want to find one that works with 3rd party open source software, like PulseView, they tend to be better.I got a handheld battery scope with 2 channels (1 channel is a toy). I picked the cheapest 2-channel one from an EEVblog forum post comparing them. It's decent, but the UI is a bit cumbersome still.
>>2991444>I think I'd get more use out of something I can connect to a PCSince you're a noob, you don't want that. All these cheap PC scopes have a shared ground so there's a super-high chance you will make a mistake probing and you will fry your scope and even worse, your PC's motherboard.Get a cheap digital scope. If you buy one of those old CRT-based scopes, they will be so heavy and complicated you will never use it.
>>2991428>>2991429>>2991431nice. what is it for tho?ps: should have used cyrillic for the labels & everything.
>>2989599what are the /ohm/ approved soldering irons/stations? i have a shitty no brand iron i got from a hardware store near my house and the tips are too big and it doesn't get hot enough for micro soldering so i need some recommendations.
>>2991518i have a quicko t12 (or knockoff, can't remember) that works fine for me. i've used it for small stuff as well as power electronics boards with heavy copper pours (t12 spade tip.)more people are recommending jbc based designs these days. geboon makes well rated soldering stations, like the tc22.
>>2991325JK flip-flop. Should have synchronous J and K inputs, as well as asynchronous reset and maybe set. Tie J high and feed clk into CLK, so the output goes hogh from a positive edge on CLK. Then pass clk through an inverter, OR it with rst, and feed both into the reset input of the flip-flop. If it’s active low, NOR it, or otherwise De Morgan the logic. I’d want to test this to see if the clock pulse at t=22 would result in the output being on for a split-second, but I suspect it wouldn’t.>>2991518If you plan on doing micro-soldering (idk, 0402 and smaller), then the JBC-like stations compatible with C115 or C210 handpiece are what I’d be looking at. If you need lots of power for copper lugs or XT90s or D2PAKs, going for a station that can also drive C245s at 100-200W might be worth considering.There’s quite a lot of YouTube reviews of these sorts of stations, there’s even an open source design I saw a build-log and review of recently, though I’d wait on that one for the next design.The Miniware TS1M looks pretty good to me, though the guy who reviewed the open-source station noted that many Chinese stations have unacceptable tip current leakage for sensitive electronics, not sure if a tiny doodad like the TS1M can have good isolation.I use a KSGET T12 station and an Si012-Pro with the same tips, but I am looking at upgrading to C245.
>>2991546>K flip-flop. Should have synchronous J and K inputs, as well as asynchronous reset and maybe set. Tie J high and feed clk into CLK, so the output goes hogh from a positive edge on CLK. Then pass clk through an inverter, OR it with rst, and feed both into the reset input of the flip-flop. If it’s active low, NOR it, or otherwise De Morgan the logic. I’d want to test this to see if the clock pulse at t=22 would result in the output being on for a split-second, but I suspect it wouldn’t.tried this in falstad but it's not working as expected. https://www.falstad.com/circuit/circuitjs.html?ctz=DwYwlgTgBAZgvAIgIwKgFwM6IAwDpsEECsqYIiRuALEQJwAcSRBAzC0lVQExWogBGFbKgAOghM1QA3CBVQBbTBQCmAWiQoAfACgoUYACkA0gDEANmBHmA9iKgAPRElpcoPbG-r03VYbEQAbAgA9Dp6wADuDk4uPh5IAR7uqPAIwqG6+lGOyIlxUAlJ2PQpOCFh+gBK0QgBVG4A7K4srlxNpcgNqBGpXCmyyAQKAIb2UohcuCRQ-GDDWAiTJBnh2Yj0Hr7xSK5bHekVwACSNRq7BAUNAVB7-mmoGGY4U6gAFmByK-oA8tA5SFcbglGrsEvtyplIqdAVQWlANjcWuCvsBqjkEbDmrskXcAd1ev1EFQulB5KNxosXjM5gslqgACYAVzQAE8AMIskBmZTPFAotaLLwgqBsa5tPp3A6QgXioHXUVy5GHAAypzyXGKBTyAKCktETghqxqCpYRGaLGuVDBev5xotIrNIvt4qVkLMADsagjZd7fOD0DyEGzlUZDfoPV7NnCMXV-WhA5UAMoAFTDwAjOQV7idYuKccD3wAqqnbTkuELs1m-TbDgKq5sLska5CALI1Lb5K1i6upKVGnJ1YXe9rN-vrJJNeENvy9tMC4euZytEezlHWKDKd1OXhQDAiJy61L2XX7+41YOhirhOwUvwYcgSMPXqAUlgPB94PmHYLWQ7rzeICSe4Hh0x76meORJqmV76DeZS7g+ywwcAcEIG+CG8mmP5-huW7ICUu6ntaR4nvBORFtBmTPre77PIQ2BXFwtAsLQNDsFwSFUbBL6IOh96YSi2HaMAwTgBAOhAA
>>2991325>>2991546>>2991642https://www.falstad.com/circuit/circuitjs.html?ctz=DwYwlgTgBAZgvAIgIwKgFwM6IAwDpsEECsqYIiALLgBxLUBMAbAJwPNLasOogBGiRbKgAO-BINQA3CANQBbTAICmAWiQoAfACgoUYABEAYgBswwkwHthUAB6IkAdkZRHz+tmounqeAiFRJJFkAem1dYABZW0R6B3ooegpsKABmbAoEpJ8cBFCdPQB5aDsEFPjE5PVyrNgcvPCAd2jkJGrKigyK7L9csL0mkqQOzPbOj26hev7mobHPVwTx2p6p4AHEMoTEqGT6RIne-LXmyqcdrYoD1YBJZpUUxk9Y+JV6aie4g6gMYxxcEigAAswCE+sAAIIAOwAJndZgkiM57uVEVcwcVEK93gk4lBXh4cfQvjJkIRDuEQHd3B8XtTUg8vuRkKoHKRJH8CChviT-JJoZRcMwhRREWUPPRmPQiKzVgBzKkElIPPF0lJEInLSZg9YIfE0vHw55oo46tTDCp4h5PGq+LUmu5WkaWx6E42NB0u554ijUXafTXk6YlZEI5ybKWMN16ABKd3VnhUvrxRGGif8vkcqAavg1MBJHH8cgAhjZ2Qh6P9ULwwEWsOXK6tTT7kmnk288b6o8dg82Da1vUm013TWKOy2I2Ou-Lg6O1EjR+m6mDKTP3GPLWu54z7Cy2RzsFyMDypPy-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-X9Tsu-TjOBmrbPfBzuDa2CutB-rlAAgT4ck5Hhvx6zrtJ8zCtlxr6eZ0c2fAME4AQNoQAokay, i think i got it. this was harder than i expected, man i am shitty at digital logic. and i wish falstad had an easy way of letting me define an arbitrary waveform for the CLK/RST relationship.
>>2991444Decent used ones hold their value. You will learn a ton with a scope that you wouldn't otherwise. The only reason they're not a must for beginners is the expense. Any scope is better than no scope, but you'll get the most for your money with a Rigol or a used Tek lunchbox. Analog scopes are very old now and can quickly turn into repair projects. A lot of the regurgitated advice to go analog for price/performance is decades out of date.
Amazon recommended me this, any good for electronics assembly? Seems cheap enough to take a gamble
>>2991715Donegan Optivisor
>>2991715it's fine. it works well>>2991716>$128come on now.
>>2991740Good tools are worth it. You don't know what you're missing until you use something better than Amazon/Ali/Temu offerings.
>>2991765>You don't know what you're missingbeer, hookers and weed
>>2991279Snub a dub
Do you anons think I can use a hot plate to recover a SMT IC surrounded by through hole components? Obviously the board won't sit flat on the hot plate. I wonder if I can get away with cutting off all the solder joints underneath, maybe even sanding the board a bit to get it flat (the board is a dud so it doesn't need to be kept intact)
>>2992004>use a hot plateuse chipquikhttps://www.youtube.com/watch?v=7kyaz4Zrd78
>>2992004Get a length of heavy gauge solid copper wire and bend it into shape so that it makes contact with all the pins at once, then wrap the other end around your soldering iron tip a few times.
>>2992004>Obviously the board won't sit flat on the hot plateYou can pile it up on sand or salt or whatever, it's what people do in a frying pan. Copper or brass or other metal shavings would be better, but sand works with enough time. You'd be reflowing every damn component though, I'd want to take those aluminium electrolytics off first so they don't boil.The solid copper wire method >>2992012 is probably what I'd try, but it's still a pain, and somewhat prone to delaminating pads if you're insufficiently careful.
>>2992010I'd actually never heard of that but it seems worth a look, thanks. There is some knock-off version on Amazon called "fast chip for quik removal of ICs"...>>2992012>>2992017Wire method sounds fiddly but worth a try (and I have wire, but not sand). It's the chip I want to save, not the board.Given that I'm posting anyway here's a progress pic, I am hand soldering everything for my first board, but I might try the second using the hot plate. I need to make 4-6 of them. Actually I got to take the new hot plate for a test drive earlier than I expected, because the first thing I did was solder a TL074 upside down. Hot plate allowed me to reorient it.I never thought I would take the surfacemountpill, but I can see the advantages.
>>2992035>There is some knock-off version on Amazon called "fast chip for quik removal of ICs"...You could always buy a chunk of bismuth for $10 or whatever and mix it with leaded solder until the melting point is nice and low. Indium and gallium are expensive, but a lead-tin-bismuth desoldering alloy should be decent and much cheaper.
My dad asked me to fix his trimmer and he wants it repaired because he can't find this model anymore. It doesn't hold the charge (it's like 10+ years old). I managed to open it up and this battery pack is completely dead.How do I replace it? What can I use in its place. Seems to be 2xAAA batteries. Where can I buy something like this? Thanks!
>>2992173It’s just two AAA rechargeable batteries in series. If you have room, you could replace it with a battery holder for a couple of off-the-shelf rechargeables. If not, you could either assemble your own pack from seperate cells (ideally ones with solder tags), or buy an existing one. Searching eBay or wherever should show plenty of 2.4V 2xAAA batteries, I know lots of cordless phones use similar batteries. If you do end up buying such a battery, it would be a simple matter of cutting the wires and splicing them together. Butt crimp terminals, heat shrink solder splices, or solder and heat-shrink will be your main options. I’d want to solder them with an iron, but it depends on what you’ve got and how much room there is. Alternatively, if there’s a connector on the other side of that battery, you should be able to identify it and find a replacement with that same connector, no splicing needed.
>>2992173They're just rechargeable NiMH AAAs. I recommend Eneloop (Panasonic). You'll have to solder (or spot weld if you have one) three joints: the positive and negative wires from the pigtail connector, and a series bridge on the other end of the pack.
>>2992176>>2992177Thanks!!Apparently, this type of a pack is used for wireless phones. They have a diff connector though. I don't have a spot welder and I'm weary of soldering batteries so maybe spending the money on a pre-made pack is the best option in this case.
>>2992180If you're careful you can push the pins out of the old connector housing and swap it with the new battery's housing. Just make sure the polarity is oriented correctly.
>>2992180Post image of connector.
>>2992180You could also forego the connector and solder the wires directly to the PCB.
>>2992181>>2992182I can't reach the connector. I can't see it... it's somewhere deep inside the device. The thing is tho, I can't even open it any further. There are no more screws left. Everything else seems to be clipped or welded. The external screws allowed me to remove the blades and the battery compartment had a cover + screw.Battery seems to be soldered to these wires so I don't think I have to open it (and probably break it) any further.>>2992183>You could also forego the connector and solder the wires directly to the PCB.... or do what they did and just solder the wires.Now I just gotta find this battery...
can someone explain what i would need to get to make my relay switch A: not knock out my esp8266 from sucking all the amps out of it, and B: not sending any pulses through the rest of the electric grid? I have AI help me with some of this shit becuase I'm a retarded newfag but every time i look around online it feels like I'm being asked one of two things: be horribly ripped off for components because local part stores arent in my area, B: get a decent deal on multiple whatevers and theoretically never ever use the rest and haul them around forever.I have no idea how to select and buy parts. I feel like I'm too stupid for stuff like this sometimes. building a gizmo to turn a fan on depending on indoor and outdoor temps.
>>2992229>explain- replace wimpy power supply by brawny alternative- add big ass cap across supply to smooth out spikes- use 2 diff supplies (with grounds tied together) one for sensitive parts, another for brute parts- isolate relay power from rest of circuit by adding diode in series, and a big cap in parallel- replace relay with power transistor, TRIAC, MOSFET, or solid-state relay
>>2992010you can get knockoff chiquik on aliexpress for a fraction of the price.
>>2992229You have to drive the relay coil with a transistor. Turning mains voltage off and on with a relay is not a good beginner project.
Respectfully seeking review on this PCB design. I’m making a low powered “dumb watch” (MCU runs at 2MHz, i2c is slow, and total power is like 7µa) and this is the first PCB I’ve ever made. Idea is that a coin cell battery clip is attached to the bottom of the board (negative terminal sits directly on exposed pad which is part of a larger GND fill). I believe this constrains all power and signal to the top layer, lest signal routes make contact with the negative battery terminal on the bottom, but it does make the signal routing pretty messy. Curious how to improve this; the i2c ‘bus’ was particularly hard to route but I tried my best and am hoping this works.
>>2992010> chipquikI fuckin love low-temp mystery metals and contamination in my joints. When components get hot, i love it when they fall off the board onto the hv power control pcb. I love the way the mystery metals oxidize into this grey nonconductive powder and cause cracking with thermal cycles.> why not use mercury?Yeah, at least I know what the metal is there.
>>2992259I haven’t worn a watch in 27 years. No need.
>>2992229Look into snubber networks for relays.You can isolate the whole thing with an optoisolator circuit on a separate power supply (or just a led and photodiode/transistor and a piece of heatshrink)
>>2992185man its so low current that you can just twist the wires properly and heat shrink themalso I'm sure someone sells that exact configuration on nimhdon't use lithium, you can use 2 double A or AAA NiMH batteries in a spring loaded housing if it fitsmake sure the housing puts the batteries in series, because a singular cell is 1.2, 2.4 is when two is in seriesyou can tell this like, 2 separate tabs and one connected tab, these usually come with cables coming out of them too
>>2992229Yeah I’d use an optotriac switching a proper triac, but that would require a properly isolated circuit layout, not something you’d want to do on protoboard.If you’re using a mechanical relay, you might be able to swap one relay for another that has a higher coil resistance, and so draws less power. I assume you’re switching it with a transistor and a freewheeling diode? Post schematic and current parts BOM.>>2992259Looks fine. You may want to add a little solder blob for the negative battery contact to touch. The ground plane and low frequency makes any shitty routing quite forgiving. Don’t be afraid to order a board and test. What MCU?
>>2992259you don't need a ground pour, put 3 or 4 pads for GNDwith such a small and low speed mcu the quality of the gnd barely matters I guessif you post the project folder I can try an alternative route
>>2992273It’s comfy to leave my house without a phone but I still like to know the time.
anyone who doesn't at least own an f-91W is not a real DIYer
>>2992288GND fill is mostly just for making routing easier, and don’t really see a downside to keeping it. Thanks for the help.https://mega.nz/folder/unRCzIjK#ODTxdGjxlZ3eZhUtUBLmVQ
>>2992292I can't even right click pick the bottom gnd fill zone, what gives?
>>2992296Not an expert in this, but is it the “selection filter” in PCBNew? I always toggle with the GUI depending on what I’m working on, but when I shared the file the zones part is unchecked as shown in the kicad_prl file.
>>2992298I didn't know such a feature existedanyways what do you think? 3v3 fill on top, GND on bottom
>>2992304Thanks for helping me, anon. The 3v3 fill on top is brilliant and definitely cleans things up. Do you see any issue with the green vias shorting to the negative terminal of the battery (red circle)? I thought that even signal traces would be an issue on that bottom layer within the red circle, since solder mask is the only electrical insulation.
>>2992318Unless you want to add an extra layer of lacquer, I’d want to avoid vias in there. If it was a static device that’s one thing, but something in motion with knocks and vibrations doesn’t seem like a robust design.Anyone have opinions on those lillygo LoRa watch devkits?
>>2992318you can put silkscreen, the white stuff, as an extra protection layer on top of them, but I assumed you were going to add slight amount of solder to that GND pad that touches the button cell? that would put a 0.1mm gap between the trace? you can add kapton tape there as wellis there a picture of the battery holder you gonna solder?
this could have been a really sleek low profile board were it not for those gigantic capacitors :(
>>2992327you can mount them sideways, or go for polymer smd caps?
>>2992329on reflection I suppose I could have used axial capacitors, I already had those ones in stock, though.Surface mount electrolytics sounds hard, although I will be trying my first hot plate soldered board soon which might make it more feasible than using an iron.
>>2992331I meant the niobium capacitors
This image just makes me think>NOT ELECTRONICS
>>2992333huh, I'd never heard of those. Thanks anon, interesting
>>2992336you know they also make flat solid polymer aluminum capshttps://www.jmbom.com/blog/capacitor/sp-cap-conductive-polymer-aluminum-electrolytic-capacitors/734look at all this marketing
>>2992339well gosh it seems like I have been living in the pasttruth be told I have very little idea what I am doing and it's a miracle I've gotten this far
>>2992287MCU is an STM32L072 in LQFP48 pkg. Low power usage is the biggest consideration and I’m trying to get 2+ years of battery life on a 180mAh CR2020 battery.>>2992321Never heard of that dev kit. TI made one too, but it’s been discontinued. Not really a fan of smart watches; already have too much junk that I need to remember to charge.>>2992325Yes, I’m planning on putting solder on the pad, but I’d rather have reduced failure risk on the bottom layer than prettier tracing on the top layer. They also make little springs for negative contacts, but I’ll try the solder dots first.
>>2992349At some point around the 1 year lifespan mark I’d be wanting to try incorporating energy harvesting. Amorphous solar cells are the obvious way, but a full wave rectenna might be able to work with the right electrostatic design. A little sprung magnet bouncing about inside a solenoid could charge while you’re walking too. Worst case you could have a wide power harvesting coil and a bedside magnetic transducer to trickle charge a device within a metre of it.Gonna have a backlight? A screen sleep option based on orientation or brightness?
Japanese capacitor company released some Chinese cartoons to promote their techhttps://www.yuden.co.jp/en/product/special/feremo_comics/
>>2992334It's a tank with oil spilling out
>>2992272>I fuckin love low-temp mystery metals and contamination in my joints.remove it with braid? also what components are regularly getting over 138C?
>>2992327I forgot to add a couple of resistors in the schematic and the board is unusable as a resultit's been nice knowing you, anons
>>2992436You can't cut a few traces and bodge them in?
>>2992477nah, the trace I'd need to cut is actually underneath an IC. And I need to make 4 of them, so they need to be right.time to wait for the replacement boards to be shipped I guess
>>2992436>it's been nice knowing you>>2992494>time to waitoh, got impression from prev post you were gonna do the only honorable thing, which is seppuku but you've decided living in shame is betterit isn't
>>2992499I figure the least I can do is leave the corrected PCBs in a box for somebody to discover in the future and continue the work I was unable to
>>2992494So you remove the ic, flip it upside down, and dead-bug skywire it after cutting the trace. Kids today.
>>2992393When that shit mixes with leaded solder it drops, probably below 80C, and also becomes extremely weak. But it should be pretty easy to flush it away with a solder wick and excess solder.>>2992494Bah, I shipped 4 boards with horrible bodges on them. Specifically, wires going to a voltage regulator because the included AMS1117’s 15V rating was too marginal for automotive use, and bent leads of a P-channel MOSFET because it was backwards.WHY THE FUCK DO P CHANNEL AND PNP TRANSISTORS SPAWN IN UPSIDE DOWN?
>50+ parts on perfboard, a couple hundred connectionskill me, the fuck was I thinkingNext time I'm ordering a circuit board, even if I have to populate it myself it's so much better than perfboard. Still gonna finish it at this point but man this is so ass
>>2992233>>2992236>>2992274>>2992287you fags are vastly overestimating my skill level.
>>2992690Are you at least using vero-board?
>>2992732I said post schematic you root
>>2992734I dont have one of those, but its also not necissary, imagine an esp8266 with 3 temperature sensors on the pins and two going to the relay which is this monster.https://www.amazon.com/Iot-Relay-Enclosed-High-Power-Raspberry/dp/B00WV7GMA2this thing is probably meant for actual arduinos but I didnt realize it would suck my esp dry like a 6 year old squeezes a caprisun because I dont know anything about electronics. i just dont want to buy off the shelf crap that doesn't do exactly what I want (take the temperature in multiple locations and do math to turn on a fan). my actual small electronics skill level is "i know what a trace is" and not really any further.
>>2992736Fair enough. Sounds like the relay box is drawing too many amps, but the question stands: is it just drawing more current than a GPIO pin can supply, or is it drawing more current than the ESP32’s power source can supply? If it’s the former, not much you can do besides adding a transistor module or whatever to switch it on and off. If it’s the latter, upgrade your power supply. What is powering the esp?
>>2992736>>2992760If you go to digital-loggers.com/iot2faqs.html you’ll see that the signal current should be just 0.2mA, which the ESP is more than capable of providing. I suspect either you’ve wired something wrong (ground reference maybe? inb4 capacitive dropper) or the iot relay is faulty.
>>2992761i dont know what you mean by ground reference but the relay pin ground is on the ground next to one of the 3.v pins on the very edge of the card. the relay pin is on d1 which i thought is safe enough, am I wrong there? flipping the relay also causes one of my monitors to turn off and on thats not even connected to the power splitter in any way, and I've tried powering it through the downstream splitter or on the always on portion of the relay with no differences in outcome.
>>2992762That wiring seems fine. Yeah I’m thinking it’s faulty. Ditch the ESP and turn the relay on with a 9V battery or whatever to see if it still causes power surges, or trips a breaker or whatever.
>>2992763i used a 9 v battery and no backflow happened and the thing smoothly switches on i guess. i dunno if that means my esp8266 is just dogshit, i can produce the exact model if you suspect it i also used slopgpt to do the coding but it seems to just be a standard Arduino relay command.
>>2992764yeah after putting everything back together the way i had it before the relay still causes the esp to stop taking any readings from the temp sensors until a power cycle. the wierd problem where my monitor would flicker seems gone for some reason though. maybe it would come back if i plugged everything back into the strip?
>>2992764>>2992765Ok, now try powering it from another 3.3V source, maybe two AA batteries in series will be close enough. If that works, try powering it from the GND and 3.3V pins of the ESP directly.Again, what's the power source for the ESP? A USB power brick?I'm guessing the monitor flickering is from some load feeding noise back onto the grid from switching a funky load, might want to look into an inline filter. But for now continue testing with nothing plugged in.
>>2992733Nope. Pretty much just this shit, but a little bigger. It's will be fairly densely packed when it's done.Already have a bunch from years ago and all the parts on hand so I figured I might as well use them. I should really stock better prototyping board.
>>2992690learn how to etch your own PCBs. i don't know why the reddit types (that's a lie, i know exactly why) are so opposed to etching. it's perfect if you only need 1 layer, or 2 layers if you're a masochist.>Y-YEAH BUT WHY WOULD YOU WANT TO DO THAT WHEN YOU CAN PAY JLCPCB $10 AND WAIT 3 WEEKS TO GET 5 BOARDS WHEN YOU ONLY NEED 1 BOARD NOW!!!!!!
is there a good way to switch 230V AC with a microcontroller? got about 12 components to control, and they should all be <1A, except the heaterwould a triac directly on the MCU IO pin work, or would i need to fuck around with optocouplers/a dozen parts for each thing i want to control?dishwasher timer assembly got stuck in drainage mode forever and replacements are very expensive, so i'm considering programming one
>>2992782If you have a reliable and repeatable process without too much labour, yeah. But if you don't have a laser printer, it's kinda shitty. I never had much luck with inkjet transparencies, the contrast ratio was never good enough for crisp traces and idiot-proof developing. Also my shitty photoresist film had thin spots in it. I prefer just hand-painting traces with etch-resistant lacquer instead.If anything, I'd recommend a CNC router or laser.>>2992786If you don't care about continuous control (e.g. PID) and just want to turn it on and off no more than once a second, probably just a triac, optotriac, and a couple of passives. If you want to do something like PID for pulse-skipping or full-on phase-angle control, you'll need to measure zero-crossing and trigger the optotriac synchronously to the mains sine wave.You can buy modules that do the hard parts for you, see:rbdimmer.comWhich I already found and shilled earlier: >>2991405They do boards with your optotriac and triac on them and just need jumper wires to a micro. They also do boards with their own pre-programmed chip that talks I2C or UART and outputs a proper synchronised signal, if you need that. It's cheaper on their website than on aliexpress for me.You could buy someone else's triac module, though these guys (and Kemo) are the only people I know that do a digitally controlled idiot-proof synchronous triac control.
I lack understanding regarding the workings of the baxandall bass/treble control.how do I properly display the controls digitally if the pots are linear? Right now I am just mapping the dB scale linearly like this: dBf = (float)(bitValue - 128) * maxDb / 127.0;the range of the controls is -15 to +15dB.bitValue is the 8 bit value sent to the digital pots. is this correct or should I use the amplitude gain function somehow: dBf = 20.0 * log10(gain);
>>2992782If I did circuit boards regularly I 100% would consider it.CNC milling boards is also appealing, but the lower precision is pretty big downside and I'd never recoup the cost unless I needed it for other things.
>>2992787granted i've only done it a few times, but i used transparency on my shitty $50 inkjet and it worked just fine for SOIC-8 and 0402 packages.
>>2992805Having the decibels proportional to the potentiometer position is probably the way to go. That means the actual gain equation is nonlinear.Also consider using fract and accum instead of float.
>>2992844so the 20*log equation?>Also consider using fract and accum instead of float.interesting. can you link me some video/guide on how to replace float with this?thank you, anon.
>>2992922Yeah. Though if you’re multiplying your signal by a gain, it will be signal_out = signal_in*10^(dBf/20). Exponentials and logarithms like that are computationally expensive, so I’d probably just use a lookup table instead, assuming you’re doing it live on a microcontroller.As for the Fract and Accum, they’re fixed-point data types that are optional in the C programming language, they’re implemented in the GCC compiler. Tried to use them in my arduino IDE ESP32 project, but whatever compiler that uses doesn’t support them. All I could read about the data-type was just occasional forum and stack-exchange posts. Again, fixed-point is kinda autistic and superfluous unless you’re pressed for processor power/time.
>>2992925optimization is not that important for this instance. I'll be happy if it works. Even with the on the fly calculations it's still fast enough not to have any noticable difference on the sluggish hitachi LCD. Now displaying dB for the audio pot works - 6dB is at 50%.but with the baxandall controls it's at 9dB when mid point - shelving when pot is at 50%:void showDecibel(byte x, byte y, bool showSign, bool showUnit, bool oneDecimal, int bitValue, float minGain, float maxGain) { lcd.setCursor(x, y); // Eingangsbereich absichern bitValue = constrain(bitValue, 0, 255); // Pegel berechnen float gain = minGain + ((float)bitValue / 255.0f) * (maxGain - minGain); // Schutz gegen log10(0) // if (gain < 0.001f) // gain = 0.001f; float dBf = 20.0f * log10(gain); // Auf gewünschten Bereich begrenzen //dBf = constrain(dBf, (float)minDb, (float)maxDb); float absVal = fabs(dBf); // Vorzeichen if (showSign) { if (dBf >= 0) lcd.print(F("+")); else lcd.print(F("-")); } // Zahl ausgeben if (oneDecimal) { if (absVal < 10.0f) lcd.print(F("0")); lcd.print(absVal, 1); } else { int value = round(absVal); if (value < 10) lcd.print(F("0")); lcd.print(value); } // Einheit if (showUnit) lcd.print(F("dB"));} showDecibel(8, 3, true, true, false, treble, 0.1778f, 5.623f);
>>2992931Ah, so you're not doing DSP, rather you're just calculating and displaying the gain of an analogue circuit using the second wiper of a 2-gang pot?>it's at 9dB when mid pointdB is a multiplicative measurement, it may be you just have the wrong offset? If it's a log pot it doesn't matter, even if the mid-point isn't mid-resistance, the calculation should still be correct. Are you measuring the gain difference of the tone control with an oscilloscope? It's possible you're measuring an area still on the 20dB/dec slope and not seeing the full gain change.Not sure what you mean by "shelving". Post images if you can, diagrams and/or waveforms.
>>2992932I'm just controlling a baxandall with 2 digi pots. I also have a baxandall logarithmic volume control circuit with another pot. 50% at the volume pot should be -6dB volume attenuation.For the baxandall it's different.>Not sure what you mean by "shelving". there should be no amplification/attenuation of the bass/treble when the pot is at 50%.Right now I'm just showing a simple percent scale.https://www.guitarscience.net/tsc/baxandall_2.htm#RIN=600&R1=22k&R2=22k&R3=22k&R4=10k&R5=10k&RB=100k&RT=100k&RF=600&CB=47n&CT=1n&RB_pot=Linear&RT_pot=Linear
>>2992777no longer needed. I begged ai for some help about the issue, after narrowing some constraints like me being a retard who cant just buy parts easily because i dont really know what i am doing, it came up with a pretty decent idea. run the pins power from the open gpio D and Rx. once I do that, I can hard cycle them in software and save the thing from having to restart, thanks for your general assistance regardless. also i dont know why but the monitor no longer flickers, though again, that could be that i have less stuff plugged in right now.
>>2992932turns out using a reversed log scale is not represantative of the baxandall setting.Problem it's not exactly logarithmic but also not linear, so since I already wasted too much time on this miniscule issue I'm just gonna display dB linearly from -15 to +15dB, even if it does not correspond to reality.
When a piece of equipment running it's own embedded OS says "Power - 3.3V - 5V (operational voltage 3.3V)", does this mean just any USB battery pack with a jack adapter will work from amazon?I'm electrically challenged and not trying to fry expensive shit.
>>2993205It means that you use a 5V power bank or a 5V USB charger, and there is circuitry on the PCB to convert that 5V DC to 3.3V DC.
>>2993205>does this mean just any USB battery pack with a jack adapter will work from amazon?Yes. Make sure it's a straight-through jack adapter, there are some out there that step up to different voltages.
>>2993212>>2993214thank you guys, ordering the right stuff now
>>2993205>any USB battery pack with a jack adapter will work from amazon?noyou also have to take into consideration current ratingyour supply must meet or exceed required currentand just to be super sure, check polarity of the gadgetmost everything now is positive-on-inside but you never know until you checkratings and polarity are sometimes found as a sticker on the bottom of the unit
>>2989690>Where you'll end up?Celestial Arch Priest of the order of Saturn inscribing summoning circles to bind Laplace's demon and harness its power for your photon and antimatter imager.
How do you model these fuse clips in KiCAD? You need two of them but the standard fuse symbol in KiCAD can represent just one of them.
>>2993365Make a footprint with two of them, i.e. four holes. The rail pain is that the DRC will complain if you don’t connect both pins together, don’t think there’s a way to define pins as internally connected yet.
>>2993222spooky, hopefully the one I got works. USB A 5V 2.0 amp.I'll take a multimeter and test both first before I try I guess.
Just fixed a car key by throwing away the ripped battery basket and soldering two wires instead which I then promptly taped to the CR2032 battery it needs.feels good.
Where can I get practical experience in electronics?I graduated as an electronics engineer, but I have temporarily moved to a region where there are no relevant job postings apart from basic jobs in the power/energy sector. I am even willing to design electronic circuits for free if it helps me gain skills or build a portfolio, but I haven't found anything like that.Currently I just design electronic circuits for myself, but honestly it feels different from what might actually be needed in the industry (eg. Kicad vs Altium problem). It's sad that in this field there are no equivalents of remote unpaid internships like there are in IT.
>>2993510Step up your projects, aim for something fancy. Like a GaN BLDC driver, or some ultra low noise audio equipment, or some UHF radio equipment. Doesn’t matter if you don’t know enough to build it, you learn on the way.
>>2993510>practical experienceStart out with repairs. Then move on to modifications or conversions of existing products. Once you get an idea for your own project, look around junkyards, thrift stores, flea markets, and garage sales for prototypes. Avoid Amazon if you want to save money. Avoid Ali/Temu if you value your time (and possibly life lmao).
>>2993510>I graduated as an electronics engineeraccept your obsolescence or move to Shenzhen and compete with 130,000 new EE graduates each yearyour best selling point is that you can at least write proper English documentation
can I substitute a 2N6045 N-channel mosfet with a 13N10 NPN? it's a simple shortwave amplifier. the maximum values seem even higher on the 13N10.
>>2993645Would have to see a schematic. I’d suggest probably not, because gate drive and bias circuitry differs a lot between them. If it’s a linear amplifier, getting a MOSFET into the linear region is quite different from getting a BJT there.
>>2993700yeah I see, thx. It's a linear amplifier from rm italy. schematics are all over the net. but I had a feeling that wouldn't work.
>>2993645TIP102
>>2993708You mean the RT35? Doesn’t look like a linear amplifier with that common-source FET, more like a class-C switching amp, but I don’t know shit about RF amplifier topologies.
>>2993720noted>>2993776no, it's the kl-60
>>29936452N6045 is a darlington, not a MOSFET.
>>2989599i'm trying to understand the inner workings of peak current mode controllers. i managed to get a single ended controller working, now i'm trying to model a push-pull output controller. i copied the UC3846 block diagram here. it gives me a convergence error after a few picoseconds. why isn't this working? i know that my "t flip flop" equivalent works fine (in the boxed outline) and that running this in open loop also works fine, but obviously this creates an unregulated output.
>>2993830Maybe it has something to do with unconnected inputs of your logic devices?>https://www.allaboutcircuits.com/technical-articles/an-introduction-to-using-logic-gates-in-ltspice/SPICE is also not the ideal tool to simulate power supplies. Take a look at SIMPLIS, it is much faster as it uses piecewise linear models instead of complex devices like in SPICE.
>>2993871thanks. i did try this but it gives the same non-convergence error.truthfully i'm having trouble understanding the logic at the block diagram level. i think the block diagrams are over-simplifying something for ease of presentation which is giving these errors... but i can't picture what "should" be happening to understand why.
>>2993830>>2993871>>2993875okay, i feel like a massive retard. if i check "start external DC supply voltages at 0V" it appears to work. not sure if it's working correctly, but it at least regulates to 12V.not sure why the model absolutely refuses to start up without this option enabled.
So i want to build a little stepper controller and checked out what the established designa are doing. The TMC2240(stepper driver IC) has an advanced reference designs which looks like pic rel, but everyone else uses decouplers, yet this guy uses ESD/TVS diodes. My question is why, what's the advantage? Chatty only gives me a laudatio diodes and capacitors being fundamental different things..
Does anyone know of an alligator clip that has a screw in addition to a spring, so that it can be tightened to keep it in place? It's probably by a different name as nothing is coming up on a search.
>>2993909TVS diodes will clamp any overvoltage spikes. I’ve heard of stepper motors generating enough voltage to damage the control electronics, though I’ve hand-driven my 3D printer axes by hand and never had any issues. By decouplers, do you mean capacitors across the output or from the output to ground? Seems like putting a capacitive load on the output of a motor driver is a bad idea, even if it’s got chokes beforehand.What’s the project?
>>2993934Decoups would be sitting in the same place. pic rel the reference design, what most western OSH controller boards seem to do. Chinks usually leave them out altogether. Right now the goal is basically just make stepper move and get a feeling for future designs, got a load of Nema17s from a university dumpster, a few of them cost 100€+ anew, so those i would like to treat rather well. The TVS diode design is from a 3d printer board "prunt" that boasts being able to turn/adjust the motors without blowing everything up, but then we're back to A as, as far as i got it, a decoup does the same job, as long as i don't turn the stepper actively like a Dynamo and even then the TMC comes with an overcharge protection.
>>2993936If the TMC can handle power going backwards, you’d just need a single TVS diode or MOV or whatever across the main voltage rails, if anything at all. Though with clamping diodes right on the motor, you have the opportunity to add fuses to prevent the TVS diodes from failing, but that’s likely overkill. If it’s a prototype, I figure why not add footprints for optional components, you can solder them in later if you need them.
>>2993937>If it’s a prototype, I figure why not add footprints for optional components, you can solder them in later if you need them.I guess that would've been the obvious step. Thanks, nonetheless.>Though with clamping diodes right on the motor, you have the opportunity to add fuses to prevent the TVS diodes from failing, but that’s likely overkillI'm not sure i get this sentence, i want to add diodes and caps together and put a fuse where?
>>2993938If you have the diodes as in >>2993909, you could put a fuse on pin 1 and a fuse on pin 2 of the stepper connection (one for each motor phase). That way, if the stepper is generating excess voltage for a prolonged period of time, it will blow one or both phase fuses. Without the fuses, the TVS diodes would have to be capable of dumping all the heat produced, which may result in them failing open-circuit, and so sending the overvoltage condition down to the driver and the rest of your circuitry. But this really isn't something I'd worry about unless you specifically believe you're likely to find prolonged backdriving of your steppers, and at speeds higher than they could reach at their supply voltage (motor voltage/emf is proportional to speed).I'd probably just add caps, add a footprint for chokes that's easy to short out with a jumper wire or solder blob, and add a footprint for the TVS diodes too. And maybe add a ferrite sleeve around the wire going to the stepper motor. Through-hole footprints take up more room, but are probably easier to tweak. That's what I do for my first prototypes. I'd probably add a beefy TVS (or at least its footprint) from GND to VDD, to handle spikes from your PSU or from your motor or from any other peripheral you'll have.
>>2993940Yeah, i probably stick to the multifootprint and check how close i get to kaputt everything. Thanks for the explanations.
I calculated 2,685A peak inductor current for 80% efficiency, 600kHz, 3.3uH, 5V in and 14V, 500mA out. this seems to be well below the 3.7A switching current or am I missing something here?https://www.ti.com/lit/ds/symlink/tlv61048.pdf?HQS=dis-dk-null-digikeymode-dsf-pf-null-wwe&ts=1780295300234&ref_url=https%253A%252F%252Fwww.ti.com%252Fgeneral%252Fdocs%252Fsuppproductinfo.tsp%253FdistId%253D10%2526gotoUrl%253Dhttps%253A%252F%252Fwww.ti.com%252Flit%252Fgpn%252Ftlv61048
>breadboard circuit>everything works>solder everything on a perfboard>nothing worksThe virtual ground is getting pulled down to the negative rail by God knows what and I'm so fucking depressed I can hardly deal with it.
In case you're wondering why the traces look that retarded, pic related is why (the green wires are the aforementioned virtual ground).
>>2993959>>2993961Get a multimeter and start probing for shorts or bad connections. Also make sure devices are oriented correctly (i.e. pin 1 is where it is supposed to be).
>>2993942I get 2.586 A with your numbers, but otherwise this should be fine. 3.7 A is just the value where internal current limiter kicks in. You need to make sure you stay below that and everything will be fine.
>>2993959Put a current limited 0.5V or less across the shorter nets (e.g. 100mA), and use your multimeter to find where the voltages on the two nets converge.
>>2993968>>2993995I ended up isolating the signal generator subcircuit by desoldering connections. I basically had the virtual ground isolated, just the resistors+electrolytic caps voltage divider, and a single ceramic cap going to negative and that fucking node still didn't stay put at the expected 4.5V. Then I accidentally touched an empty pad and it read back like 2V and change. I knew about leakage capacitance and the perfboard pads should cause it, but that's excessive, also because other pads didn't have this issue. In other words the board is FUBAR.
>>2993998If it’s not a low-impedance short, then give your board a good scrub with IPA and an old toothbrush. Flux residue can absolutely cause that kind of behaviour. But if it’s under 10 ohms, it’s got to be a solder or component short.
>>2993976unfortunately the efficiency graph doesn't go beyond 300mA, even though it seems somewhat linear at the 5v graph. it's propably a gamble if this will work reliably. I searched the established manufacturers for hours till I found out about Silergy. seems the chinks seem to have exceeded at the switching reg business.The SY21222 sheet shows exactly the graph that I want and is also a real bargin at 50ct/pcs. https://www.mouser.de/datasheet/3/1517/1/SY21222_1MHz_2A_Current_Limit_Step_Up_Regulator_Datasheet_Rev.1.0.pdf
Ground loop isolator. Now I can’t hear the problem it was meant to solve, so improvements will be put aside until I can recreate the buzz.I see some ground loop isolators have series capacitors on their inputs, I can’t imagine why this would matter since transformers block DC anyhow. To stop DC biases from roasting the transformers?
>>2994070>since transformers block DC anyhowin this formula, if frequency is zero (i.e DC) then the impedance of the coil is very lowor almost a shot circuitwhich could easily cause problems for a given source, such as one with phantom power
>>2994085Yeah phantom power is the only real case I can think of this being a problem. But I see this circuit being used for 3.5mm isolators, where the only phantom power you'd ever see would be the <3V ~1k impedance for a miniature electret capsule. Those are usually more than tolerant of short circuits, at least in my experience. The transformers are still hundreds of ohms in DC anyhow.
I want to transfer data through a transparent plastic watertight container, and plan on doing so via optical isolation with discrete IR LED and phototransistor. Pic is for SDA, SCL just needs a single opto. The sensor in question is an SHT35, and the datasheet claims a maximum rise/fall time for its SDA and SLC lines of 300ns. Unfortunately for me, my phototransistors have a rise and fall time of 3us, and my LEDs are unspecified, I'll probably look into using a faster photodiode alongside a speedy small signal transistor. Anyone have any better ideas? I'm already using a wireless power coil pair for transmitting power through the wall, with a magsafe magnet array so I can easily remove and replace the transmitter+sensor.
>>2994192>discrete IR LED and phototransistormonumentally bad ideayou'll run into many many headaches with noise, sensitivity, ambient light, and loss of bladder controlwhat you wanna use instead is to use a dedicated IR pair that fixes all those problems for youif rise times dont match your needs, just add a tiny logic gate at the output like the SN74LV1T04
>>2994019Cleaned it, no change. Since at this point I'd have to desolder most components, I think it's time to go with a proper PCB because sure as fuck I don't want to remake the whole board from scratch. What service would /ohm/ recommend? I see things like PCBway and JLCPCB shilled on YT, but I'm always suspicious of things advertised there.Also, what are the good practices to follow when designing a PCB?
Which boost converter IC would you recommend that could run from 2s AA cells and power 2s3p or 2s4p white chip LEDs?Or, instead of booster IC can I just use a CMOS 555 to generate a square wave and drive a step-up transformer with it? ICM7555 operates down to 2V which isn't ideal, but acceptable.
>>2994201A: it’s shrouded on either side of a thin piece of plastic, enough that SCL and SDA do not interfere, so ambient light shouldn’t be an issueB: it’s I2C communication, being limited to significantly slower than 40kb/s might be problematicC: logic buffers and IR transmitters need to be compatible with the bidirectional topology of the SDA lineD: the oscillator circuits that run off the data lines to drive the LED is quite a lot of extra complexity>>2994208I use JLC, they’re somewhat cheaper, and because they’re the same company as LCSC you can get boards assembled with their parts fairly easily. Though I’d stick to their basic/preferred parts where possible. Definitely don’t get them to solder on any THT parts, it costs too much labour.All that said, I wouldn’t really recommend making a PCB of a circuit when that circuit has a fault, without at least discovering what that fault is. Did you try >>2993995 to see where on the board the short is? I often find myself using a craft knife to ensure there’s no solder between two pads.>>2994226Extremely suboptimal design either way. Are those constant current regulators going to be linear or switching? Why not just a small resistor on each LED in an 8P configuration without boosting? Why not just boost the voltage high enough to feed a single string of 8 LEDs, and do the constant current regulation in the switching converter’s own feedback loop? A transformer topology would be ideal for high voltage ratios, but transformer design and selection is a pain so you may want to avoid this.
>>2994248I would only order the PCB and then solder THT components myself, I have enough stock of all I need. Alternatively I could try my luck with toner transfer and ferric chloride, which is what I would have done before becoming a wagie, but nowadays I prefer throwing small amounts of money at the problem. The circuit might be faulty (although as I said before it worked on the goddamn breadboard) but I need to rule out whatever is happening on the stupid perfboard and any soldering error. Maybe I fucked up something on the schematic, pic related, but I've been staring at it for so long that now it's impossible for me to find a mistake, damn human psychology.
>>2994254>I need to rule out whatever is happening on the stupid perfboard and any soldering errorAgain, did you try the current limited source technique? Just use a damn diode and a series resistor with some alligator clips, pic related. Use a schottky diode if you're paranoid about frying your silicon. Increase or decrease the current as required to get a usable measurement.Is the ground rail pulled low when turned off, as measured my a resistance meter? Or is it just measurable as too low a voltage when it's turned on? Sure C17 isn't backwards? And R13/21 measure the same?
>>2994254why would you add gain to u1b? that's a non-inverting amplifier, so it has a gain of 2, but the pot rv2 can already go from rail to railalso d3 is backwards
How much would I want to kill myself trying to solder down a flex PCB to these 21 vias?I've never done anything that fiddly. These things are ~1mm apart.
>>2994356Is this for testing or a permanent hack?
>>2994358Permanent, ideally.
>>2994367Is the flex PCB designed to fit over the board you have there? If so, it's easy. You should clean the board thoroughly with IPA, and scuff up the vias you'll be soldering to. Tape the PCB down, solder two opposing corners, remove tape and solder the rest. Use flux core dolder, and extra flux (but sparingly).
>>2994368Thanks. Designing it myself, but I wanted to sanity check it first.
>>2994370Consider using some structural element in the device to wrap the flex cable around, even the PCB edge or mounting holes, to secure it mechanically. You want to relieve stress on the joints and prevent it from moving.
>>2994370Making a mod-chip, are you? What’s the host board from? I know some such mods involve desoldering a chip, using its footprint as pads for the flex PCB, and soldering that IC back atop the flex.
Do you really need diodes for 2 solar panels in parallel? (there is shadow depending on the time of day).
>>2994475Yes. Otherwise the unlit panel becomes a giant LED and wastes your power.
>>2994478Yeah that's what i thought
>>2994356If you don't have a microscope and a decent iron, don't even bother.
>>2994491Did you forfeit the game? FAG
>>2994356those are thru hole vias, right? stranded copper wire, flux it real well, put one of the strands into the via, solder itif you can do this, repeat with all viasif the vias or tracks peel off, its over for you
>>2994275Didn't have time until now. I found out that U2 is probably fried, since one input sinks about 100mA at 4,5V.>>2994306Because I copied the circuit without too much thought. I'll add some voltage dividers on both pots to scale the voltage way down and retain full range of motion out of the pots.>d3 is backwardsMissed that on the schematic (in the circuit it was fine), thanks.
>>2994475Yes, but most panels come with diodes from what I can see. Check your panel datasheet.>>2994529Instead of adding a voltage divider, either add resistors in series with either end of the pot, or turn its amplifier into a buffer; set its gain to 1.
>>2994534Good to hear. Will check the panel specs.
I thought I was being clever putting old lithium 14500 cells in those /csg/ freebie shavers that run off AA batteries. Turns out it wears down the little DC motor brushing very fast
>>2994545By running it at more than twice the voltage?If you’re a u.s. citizen, go overseas and plug your hot comb or hair drier into an outlet and see what happens at 220 V. It’s shocking.
>>2994545If it takes multiple batteries, put 1x 14500 in and short out the other contacts with dummy batteries.
>>2994534Pots are 100k and TL072 are not rail to rail, so now that I've done the math I need to bring the voltage down much more than what I can accomplish with just series resistance.>set its gain to 1Can't. I need to get the difference between the voltage at the wiper of the two pots and that circuit is optimal this way. With six additional resistors I managed to scale the error down by a factor of 10, and they fit in the current layout, so I'll try that way.
>>2994578It's the one cell shavers. I used diodes to drop the voltage. It gets a few years of use for quick trims.The axle length is non-standard on the nose hair trimmer I used the most. So I can't obtain a replacement motor. Damn cheap shit always has to be made out of non-standard parts they sourced from one factory that immediately goes out of existence.
I tested this circuit with a bipolar LED and it works quite well. I used a 555 + 74HC74 for generating a 200Hz 50% square wave to drive the CLK signal.I'm designing a control panel of sorts. It will have loads (up to 20) of bipolar LEDs driven by an STM32F410 MCU. With this approach I would need 20 of those 74hc132 NAND chips, which seems kind of excessive. What do you think?
It's baby's first larger kicad project. Question how to draw schematics "nice". Currently my stuff is all on left pic rel, because i started from what i need > what connectors do those use. However most of other schematics i look at seem to rather focus on right pic rel where USB, SD, etc. seem to be drawn as whole from MCU labels to physical connectors. Is there any standard, preference here, or does it not matter at all?
>>2994631Opinion: If your project is complex and uses a lot of parts, lay it out like the example on the left. If it's simple, keep it simple like the example on the right. Way easier to read at a glance. You won't have to unfold your poster-sized schematic on the drafting table.
>>2994631The main goal should be clear communication. It doesn't matter if it looks neat, but you have to jump around to understand what is going on. Use hierarchical sheets and apply black box abstraction principle.
>>2994631change the DN DP to a direct connection to that esd protection part, and make the GND on connectors a global label instead of using a symbol, easier to readalso the long wires make it hard to follow, why is the canbus connector that long?
>>2994645I tried to keep things list like to make it easier to reverse. All the labels are aligned as much as i thought reasonable.>DN DPRight side isn't mine, i just used it as example. ESD protection is another slide and not all labels final.>>2994642>>2994632Thanks.
>>2994624Can’t you go for 3-wire LEDs instead? Or are they fixed? If you don’t mind the processing overhead, handle the logic on the MCU instead. Charlieplex them if you need to save on pins.
>>2994192Of course, because the phototransistors would be pulling to ground, I can just add comparators in there to pull faster, and from as weak of a photodiode signal as I want. With hysteresis for noise reduction. The LM393 and 311 seem capable of rising and falling in a hundred ns or so.
could I connect a DC/DC adjustment feedback divider after the shunt resistors like this?
to compensate the shunt voltage drop
>>2994710sure, TI says a cap between feedback and the vout can be used to make the loop better
>>2994371>secure it mechanicallyThanks, I'll keep an eye out for a good spot for this>>2994412Trying to capture video from the DS Lite. There's not much room in the case to intercept the ribbon cable, so the plan is to tap into it at the vias. I've seen another capture mod do this but it only connects to six iirc.>>2994491No microscope. If it's a must for this kind of job I'll look into buying or borrowing one.>>2994515They're all through holes, but the ones on the right are directly underneath the cable connector on the other side.
hello. how can I improve this current limiting circuit?the comparator always swings around when limiting the current. there must be a cleaner way to implement this.https://filebin.net/n2r04yvmld1c1vvv/voltage-adjustable-boost-converter.aschttps://www.instructables.com/Adding-a-Current-Limit-Feature-to-a-BuckBoost-Conv/
>>2994722It’s supposed to “swing around” when limiting the current on a varying load.If you want to “dampen” the rate of change, you could probably add a cap across the inputs of U8 or something.
>>2994722If you want smooth transition from CV to and from CC, you’ll want U4 to have finite gain. U1 already has an error amplifier on its FB input, adding too much extra gain inline with this will make it unstable. Try a gain of 100 first. You may find that there’s no gain that results in good stability while regulating the current precisely enough, in which case you could add some integral gain to U4. Differential gain could help too. Pic related is an op-amp with both differential and integral gain. Though maybe there could be a cap or resistor across C1R1.Not sure what R4 is doing.Also unless U8 is a dedicated high-side capable current sense amplifier, it’s probably better to do low-side current sensing. Common LM334/358 op-amps can sense down to their ground rail.
I'm looking to anodise titanium, and someone on /g/ said "honestly if you dont need current control you can look also for a variable transformer and a full bridge rectifier"i guess i do actually need current for lager pieces, but can someone help me with getting a desktop powersupply?i was thinking this one? but i think i need more amperage and 0-100v range
>>2995245100V range and over 10A current means over a kilowatt of power. I suggest you do more research into what specs you actually need. Current required varies as a function of surface area, if you can find a maximum value in units along the lines of “amps per square centimetre”, that will help narrow-down your requirements, if amps even really matter. If I recall, voltage is proportional to anodised colour, but that would suggest that you want to go for a barely conductive solution so the volts can be high at low amps. Or maybe the growing oxide layer increases resistance and reduces the current, so even if your circuit starts off drawing 10A at 10V, it will rise under current limitation up to the desired 100V and desired colour.There are two main types of adjustable power supply, ones with a heavy mains-frequency multi-tap iron transformer inside them switched by relays with a final linear stage, and switched-mode supplies. Switched-mode supplies are noisier and not quite as electrically robust, but produce less heat and are generally cheaper per watt, for this they’re what I’d be aiming for. If you have a spare ATX or other sufficiently powerful AC-to-DC power supply handy, you could even buy yourself a DC-DC converter module, like the SK90, if not something bigger. I’m using an SK90 with a PD trigger module as my adjustable PSU. DC-to-DC converters don’t need to be safe and isolated like mains converters do, so they’re generally cheaper per watt still.
>>2995262you mean like a computer psu? i actually do have a spare 500w one.the guide im following says "DC Power Supply: Ideally 0-120V and 3A"https://hontitan.com/titanium-anodizing-guide-voltage-chart/but ive also seen up to 3A, but thats for larger pieces than id be working with. maybe current only affects the speed of which it anodises at?
>>2995265>you mean like a computer psu?yeah, that's what she meansif you were a proper hoarder like me, you'd have six of themmeaning you could add them in series using various voltage combos to achieve anything from 3V to 72V at 20A or moreone small problem is that the grounds of all the supplies would be shorted thru the ground lug on the power cord, so you cant wire them in seriesunless you break off the ground lug, and make sure none of the cases touch each otherthis video explains it well except the faggit completely ignores the common-ground problem: https://www.youtube.com/watch?v=6i49XO19Pgwalternately, you could use ungrounded laptop chargers (at, say, 19V @ 6A) wired in series
>>2995265Yeah a computer PSU. 120V * 3A = 360W < 500W, so that would work so long as you can get 360W on your +12V rail. You could use something like this:https://www.aliexpress.com/item/1005005137521429.htmlIt can’t go below its input voltage in case you need voltages below 12V, but it could boost your 12V rail up to 12-120V. I’d put a fuse in series with the ATX in case the output shorts.You can buy ATX breakout boards that plug into your power supply’s mobo cable so you don’t have to cut wires, even the simplest ones with no USBs have fuses and binding posts.Also just so you know, 120VDC is somewhat dangerous. If you put your hand from positive to negative, you will feel it. If you have wet hands and put 120V across either hand, it might put enough current through your heart to get you feeling funky. So common sense applies, I’d want to put the high voltage stuff in an enclosure so you can’t accidentally touch it, or at least keep one hand behind the back while you’re manipulating your anode.
>>2989599I have some experience with electronics but not a lot with audio.I have neighbor problems, talking did not solve it, so I will build a child repellant, a thing that makes 80-100 dB high frequency sound.What can you tell me about piezo speakers? How are the cheap 8 ohm ones operate around 17 kHz?I can't find frequency sheets for them.Do you think a simple D class amp will do it?
>>2995397>law law etc sued policeDon't apply, high frequency sounds are not covered by the local law, and the law can't be bothered to help me in my issue.
>>2995397>Do you think a simple D class amp will do it?you may already own a stereo rated for 40Khz bandwidth; check user manual
>>2995432the transducers maybe, the entire signal chain? Nope. Measured the sound with C weighting and it was around ~60 db at 18khz. Not enough.
>>2995397Class-D amps have an LC low pass filter as a part of their design, but they’ll probably have enough power below 20kHz. Pretty easy to look up spec sheets for amplifiers at least, though I guess if you’re cheating out with chinky amps that might not be so easy.It’s also an option to not use an amplifier, and just feed the tweeter a hard square wave from an H-bridge and a DC power supply. Or a half-bridge with a big enough series capacitor or bipolar supply. Not easy to adjust the volume on that, but likely cheaper and potentially more powerful. There are also dedicated piezo driving circuits for ultrasonic cleaners and the like, maybe you can adjust the frequency of one of those.I’d also recommend against this if there are any non-deaf pets nearby.
I'm going to try to repair an early 90s Technics stereo amplifier which lost one audio channel. I have a multimeter, capacitance meter, and some soldering skills, but no oscilloscope. There's a couple of large 6800uF capacitors (filter caps?) that are obviously done for because they are bulging. I'm going to replace those at least, and probably the speaker relays just to be sure.A couple of questions for you guys:Since the boards have dozens of caps, does it make sense to replace all of them? I couldn't find any kit that contains all of the caps so I'd need to buy them individually. I could of course test them in-circuit with my capacitance meter but apparently that's not necessarily accurate.What do you think would be the most likely cause for one channel being lost? I know the main volume pot is pretty worn out but mostly at the lower end so I doubt that would be the cause?
>>2995464Volume pot could be the cause, spray some contact cleaner in there and wind it around to see if that cleans anything up. Or replace it. Caps are only going to be the cause I’d they’re output capacitors, if they’re input supply caps after the main rectifier, you’d get either both or neither channels working. You should be able to measure larger capacitors in-circuit without issue, just know that they may be in parallel with other large caps so the readings may be those sums.Do you have a service manual with a schematic? Those service manuals also usually have a bunch of DC voltages to measure, especially for setting transistor bias.A handy troubleshooting method is to feed a constant 50/60Hz sine wave into the amp (from a web app on a phone, computer, etc.) and use your multimeter in AC volts mode to trace through the signal path to find where the signal disappears, or where it appears I’d you go end-to-start.When my amp died, it overheated and one of the power resistors cracked. I’ve seen that failure mode elsewhere too. I put a DVD player atop it and the airflow underneath its low-profile feet wasn’t enough, old audio equipment have much taller feet.
>>2995465I actually have a service manual, and it has a schematic and a parts list. I don't know if it shows measurement values, I'll need to check. What about measuring small caps in-circuit?
A stupid question perhaps, but what do you think could have broken on the motherboard of a laptop dropped one too many times?The power LED lights up briefly but shuts down shortly thereafter. I scanned for any missing resistors/capacitors/chips and couldn't find any. Pointers would suffice, if you would be so kind.
>>2995466Smaller caps might be measurable, but they might not be. Desolder one leg and it should be very feasible.Post schematic.>>2995472I’d look towards connectors and weighty components. Things that are likely to rip off pads when shocked. Power components like inductors and transformers, anything bolted or glued to a heat-sink, definitely your SATA port if it’s got one, maybe M.2 or RAM.Also display cables are pretty delicate.
>>2995464>What do you think would be the most likely cause for one channel being lost?dead output transistors is always the most likely causethey're the parts that works the hardestso they get the holocaust treatment: Extermination through Labor
>>2995462>I’d also recommend against this if there are any non-deaf pets nearby.luckly no, first thing I've checked. And It'll be just for a few minutes. I unfortunately can hear up to 20 kHz just fine, even though I am 40>>2995462>It’s also an option to not use an amplifier, and just feed the tweeter a hard square wave from an H-bridge and a DC power supply. Yeah, I think I'll got for something like that.Thanks.
dunno if this is the right place but how do i safely not kill myself trying to repair an old microwave oven?
>>2995562very carefully discharge the capacitors with a screwdriver or something like that. Google videos of that for your specific model or something similar.They are the big capacitors on the HV side of the system. Probably will make a loud clack and flash when you do it and damage the tool, so use something cheap.
>>2995564sounds like a good way to unsafely kill myself
>>2995562>repair an old microwave oven?microwaves aren't really repairable gadgetsmost you can reasonably do is replace a dead fuseif that doesnt fix it, borrow $20 from the bank and hitchhike to a thrift store
>>2995567https://www.youtube.com/watch?v=GaNbS-KEgrw>>2995575I had to replace a fan on mine. SHitty shaded pole couldn't start anymore. Without it it could only go up a minute before killing itself.
>>2995581>https://www.youtube.com/watch?v=GaNbS-KEgrwthat's a shitty technique coz it uses both hands if you screw up, your heart is gonna be in the current loopbetter to use long-nose pliers coz you only need one handand your heart never gets achy-breaky-n-shit
>>2995575I totally fixed my microwave.something was making a buzzing noise and could never turn on the cyclotron.Turned out to be a bad electrolytic capacitor letting too much unsmoothed pulsating DC through to the relay coil. 47 μF.
door switches wear out and they're both cheap and easy to replaceThe safety section here is pretty good:https://www.repairfaq.org/sam/micfaq.htmBasically, don't fuck with the HV circuit. If you can't tell what belongs to the HV circuit, don't fuck with it at all.But it's probably a blown fuse, bad door interlock switches, or maybe a blown thermal fuse if you've done something weird with your microwave. All of those can be replaced without even getting near the HV parts in most microwaves.
>>2995562>dunno if this is the right place but how do i safely not kill myself trying to repair an old microwave oven?there's a thread on here about just that:>>2958927>>2995575>replace a dead fuseor a dead door switch.
>>2989599I need to mount an ESP32 to a PCB board for a permanent installation. I'll only be using 4 pins out of the 36 on the board. Should I...A) ...solder ALL the female header pins to the board, even though I'll only ever be using 4?B) ...solder only the 4 needed female header pins on each side, but keep the header the full length of the ESP32 (18+18)?C) ...cut out and solder individual headers only for the 4 pins that are needed?pic related
>>2995844>I'll only be using 4 pinsJust solder wires or use jumpers.
>>2995844>for a permanent installationif it's permanent, then you shouldnt use female headers at allcoz it adds a point of failure: bad connection caused by oxidation or moisturejust solder the 4 male pins you need and maybe a few more for rigidity
>>2995845>Just solder wires>just solder the 4 male pins you need and maybe a few more for rigidityI'm a pussy when it comes to soldering and afraid of applying too much heat onto the ESP32 side so I thought female header would be easier in case of fucking up. I keep underestimating how much heat they can handle.>or use jumpers.You mean DuPont wires like this? This was my initial choice but I read somewhere that these were for prototyping and not really recommended for permanent installation, and as >>2995846 points out>coz it adds a point of failure: bad connection caused by oxidation or moistureI thought these are more likely to suffer from that compared to female headers which seemed tightly sealed when pressed all the way in.
>>2995853>I'm a pussy when it comes to solderingPractice on junk. It's easy. To help you on your way, tin the wire first and trim excess length so there is just enough wire exposed to solder the joint. Add a small amount of flux and fresh solder to the pins. Then hold the tinned wire to the pin and touch it just long enough to melt the solder together. Practice.
>>2995397>80-100 dB high frequency soundI don't think this will be quite loud enough. You'll want at least 120 dB as that's where things become painful. I was trying to develop dog barking deterrent by blasting a very loud ultrasonic chirp over phased array emitter, but I'm not sure how effective this would be. Low power noises are not going to do anything useful. You want to induce pain for reinforcement training, but it's difficult to transmit so much high frequency power as it gets rapidly attenuated in the air. What you need is an ultrasonic LRAD, but that's a bit difficult to build for a hobbyist.Another interesting thing is to build a ultrasonic array but then use a special driver to modulate audio in such a way to produce sound in a very specific direction like a beam (ultrasonic directional speaker). Here potential is to mess with people on deeper level as it is impossible to determine source of the sound. Beaming creepy sounds at neighbor's bedroom at 3 a.m. would be very funny.Another way to use sound is to go to lower frequencies by utilizing rotary subwoofers. Basically, you turn your entire room (like a garage) in to a resonant chamber, sending vibrations that travel very far making people feel uneasy. This is probably best used to mess with people's sleep so it is only usable when you're not at home.>https://www.youtube.com/watch?v=NZKCxIuJ-5MThen there is a whole chapter of "chemical warfare" by utilizing stinky chemistry. One idea I had is to repurpose a vortex cannon to shoot smelly vortex rings at the sources of noise, but I'm not sure how to make it stealthy. I guess it could work with speaker as an actuator, but I don't think range would be ideal. It's probably best to first generate some HHO gas and explode that to generate the impulse.>https://www.youtube.com/watch?v=JSm7Tp8iv3oI have yet to find a good tool to deal with shitty neighbors.
>>2995853>I'm a pussy when it comes to soldering>I keep underestimating how much heat they can handleAre you using good solder and flux and a semi-decent temperature controlled iron? Cheaping out on tools and supplies will make learning unnecessarily difficult because you can't tell whether you're fucking up or Chang's finest is fucking you over.
>>2995905not him but what's the correct temperature to use?
>>2995855Oh I know how to do it, it's just that I had a bad first experience with component-to-component soldering (wire soldering is easy) perhaps because of dodgy components (chink bulk mosfets) so it diminished my confidence when the thing failed.Also I thought if I do it this way then it's messier to replace the ESP32 with desoldering as opposed to pulling the thing out of the header slots.Additional retard question, I should solder the wires onto B since the male pins already exist, right? It's it's a pinless unsoldered board then it goes onto A(?)>>2995905Hakko 888D, Kester solder, and CAIG rosin. Literally the best.>Chang's finestThat's what happened I think so I never tried such soldering jobs again
>>2995919You can solder to B if you want, but you might have problems if you try to reuse it in a header socket. A is the preferred way and you can use smol wires for signals, but try to keep the length as short as possible. You might want to twist data pairs to reduce EMI. Also, you don't have to remove the pins from the ESP. Just solder directly onto the contacts.
>>2995921Also make sure to insulate the rest of the pins.
>>2995921>>2995922Noted, many thanks anonI got 3 projects, and just realized that one of them is using a component that has DuPont connectors, so I'll just use those, but for the rest I'll have to do soldering.>Also make sure to insulate the rest of the pins.So after all soldering is done, I should spray this onto the exposed pins (B)?
>>2995934Don't spray any connectors with conformal coating. That's for PCBs that will be exposed to moisture and airborne contaminates. It would be better to use a female header, hot glue, tape, etc. Or you can cut the pins flush with snips.
>>2995936>hot glueOoh I vaguely had it in mind but couldn't remember what it exactly was. This sounds great but I'm worried it would be a hassle to remove if I need to use the pins some day.>tapeShould I wrap tape around each pin or can I cover a whole side? I know it's a giga retard tier question but I wanna be sure. I'm really learning relatively new stuff here, and the thread's on bump limit anyway.
>>2995938Cover the whole side. The idea is to prevent shorts to ground while the board is powered. If you secure the board in a case then you don't really need to insulate the pins.
>>2995940You could shrink wrap the whole board in cellophane, or use large-diameter heat shrink instead of a case.
>>2995922>>2995936>>2995940>>2995941please ignore this guyeither he's trolling or has gone off the deep end
>>2995917It varies based on your iron, your solder, and what you're working on. You should be able to flow solder maybe half a second to a second after touching the iron to the joint. You don't want it much hotter than that though, or you run into issues with oxidation etc.I think I keep mine set to 300C most of the time. But mine is an uncalibrated 936 clone so I don't know what temperature that actually is.
>>2995945What's so crazy about any of that?
Does anyone here have an industrial camera for their electronics microscope? I'm looking at getting one but I don't know what to get. Anyone have a recommendation?
>>2995853>I keep underestimating how much heat they can handle.Through my bumbling I've never managed to destroy a chip/uC board by lingering with a soldering iron, even if I fuck up and have to reflow some of the connections multiple times. Sure it's possible, but if you basic soldering practices (as in, literally any tutorial) you'll probably be fine.Even if you do, it's not like an ESP32 is that expensive.
>>2995991Soldering it's rarely a problem. If you've got a reflow plate or hot air, maybe it's not too hard to cook the board for too long, saw that on a youtube video recently when his reflow plate was set to 350 instead of 250.But I've definitely overheated a part or two when trying to desolder. Usually it's just that the plastic gets too hot, but I'm pretty sure roasting components with an iron for like 30 seconds of solid contact isn't good for the silicon.
>>2995940>>2995941>If you secure the board in a case then you don't really need to insulate the pins.Oh that's great to hear, they're going into a box anyway.>>2995945Why am I "trolling"? I'm being genuine here and really trying to learn best practices. Otherwise I wouldn't have bothered to ask >> in the first place and just went with that.If you're really looking for a laugh then how about I put up the entire plan then? (9000 years in MS paint ofc and not to scale)The plan is to have the ESP32s reporting to Home Assistant the status of the gates. They already have ESPhome installed. Project Box #1 is a straight-forward gate OPEN or CLOSE. Box #2 is the same, but includes a switch to see if the gate is bolted down or not. Box #3 is to determine how much % open or closed the sliding gate is, and to inform if the gate is moving open or shut.Project Box #2 was already installed a few years ago but lacks the ESP32. Instead it has a photoresistor for daylight detection and uses an LED to act as a visual indicator at night, running on two 9V batteries in parallel that lasts only a few weeks.Both batteries are Lithium Ion batteries with a rocker switch so that they keep running unlike power banks that would shut off if low current is detected. The ESP32s would be sent to deep sleep if there's nothing detected from the pins.
>>2995997Forgot to link >>2995844
>>2995997>Why am I "trolling"?wasnt addressed to you, but the dude making silly suggestions about covering circuits in hot glue, tape, heat-shrink, cellophane, or anal lubeyou never see that silliness in gadgets you open upin rare cases where components need protection, the only ANSI-compliant solution is Hello Kitty band-aids
>>2996010>you never see that silliness in gadgets you open upAnon is using ESP32s to open and close gates. He's a beginner and it's important for him to know not to short things. The suggestions made were helpful to that end. Now that we know Anon is mounting the boards in a case, he doesn't need to worry about insulating the pins from shorts. Do you comprehend?
>>2995997With those waterproof boxes, you’ll have to decide if you want them hermetically sealed and resist air pressure changes and condensation, or to be open to the air and just have a roundabout path so water drops cannot intrude. For the former method, you’d want to close the box up on a cold dry day, or with desiccant inside, perhaps both. And you might still get air leaking past your cable gland or even inside wire insulation. For the latter, I’ve seen some people making windows with gore-tex, but it’s not like gore-tex prevents humid air, just rain drops, so an empty downward-facing cable gland would work fine too. Maybe with a fine rot-proof cloth to stop insect and dust ingress. It shouldn’t matter if humid air can enter the box so long as it can exit easily enough and equalise with the exterior humidity and temperature.>>2996011Instead of recommending that the pins be insulated from shorts with tape or hot glue, wouldn’t it be better to just recommend that the ESP32 is placed inside a case?
>>2996066>wouldn’t it be better to just recommend that the ESP32 is placed inside a case?It was suggested here >>2995936Go back to OPs first post >>2995844>I need to mount an ESP32 to a PCB board for a permanent installation
>>2996076My fault, it was suggested here >>2995940
>>2996077Yeah but I’d have suggested putting it in a case BEFORE hot snot. Neutral-cure silicone is better than hot snot anyhow.
I’ve got some amplified PC speakers with a 2-pin mains cable going into the amp+woofer assembly. It’s got a mains hum I’m trying to eliminate, but looking inside there’s a switching power supply. the amplifier is a single-chip power amp like a gainclone. The caps look fine, and I added a bunch of common-mode ferrite chokes on the AC and DC power lines (plus the sub wires) but got little improvement. Grounding the system’s 0V rail seems to reduce the noise a lot, but when I plug it into my grounded computer the noise gets a lot worse, so either way I’ve got to add a pair of isolation transformers. So I figure I should replace the two-wire power cable with a 3-wire one, but even grounded I can still hear a tiny bit of 50Hz hum, plus some high-pitched whining coming out of the stereo speakers.Any clues where to go from here? I can think of the following options:>it’s E-field noise - grounded metal shielding between the SMPS and amp>it’s B-field noise - iron shielding, minimising loop area by twisting wires>it’s normal-mode noise on the output of the power rail - more capacitance, RC or LC filtration, a capacitance multiplier, better PSRR inside the amp circuitryAny thoughts on what’s most likely? I guess if the humming is 100Hz or 50Hz that should tell me whether it’s coming through the power supply. If so, then adding extra capacitance to its input might be tough, and dampening it with output capacitance would be hard too.The whining is probably the ~10kHz switching I saw on the scope, that would definitely be pretty easy to stamp out with a normal-mode choke or LC filter if it’s conducted noise not radiated noise. The amplifier PCB doesn’t have a seperate ground plane, but it’s star-grounded with thin gaps between the star traces and the other traces, so loop area shouldn’t be an issue there. It has an aluminium chassis bent around the amplifier board acting as an enclosure but also shielding, grounding that should block E noise.
>>2996102I have a similar older set and I too got that issue. Sometimes it starts humming loudly so I just pull a bit on the audio cable going to the PC, it makes some static noise as I move it, and after that the humming is usually gone, so I don't think it's an issue with the power supply, the audio cable must be acting as an antenna.
>>2996102Try cleaning the volume pot and power switch.
>>2996114It's almost certainly not one of those. A dodgy pot might make a scratching or buzzing noise as it's adjusted, but it seems to work fine. A dodgy power switch can't be the problem, the power switch isn't getting hot and there's no intermittent power.There's already a ferrite bead acting as a normal-mode choke on the amp board right as the +12V comes into it, I'll make it a lot larger and add a diode across it so it can't inductively spike my power rail from an intermittent load. I'll also add a zener across the supply to be sure.
>>2996118>I'll make it a lot larger and add a diodeDid it hum when it was new? You shouldn't be adding components willy nilly. Test the power transformer and replace the 3.5mm cable with a 3.5mm jack and use a new patch cable.
>>2996118Ok I’ve added a pair of new holes for the new components. There was room on the board so why not. Pin vices are great, shitty blunt chinesium drill bits are not.Found an FR207 to be the freewheel diode, and a 1N4748 22V zener. Would rather have 15V, but the cap is rated at 25V so I’m probably fine. It’s probably ~5A maximum (25W @ 12.5V with a class-AB), so my 0.63mm magnet wire would be pushing it for the choke, 1mm would be safer. I’ll have to look into which core will get me the most inductance or attenuation at 10kHz without saturating at 5A, not that I ever run it near full power.I think I’ll just jam an IEC C14 in the case, and replace the cable entry with a blanking puck or fuse or something.>>2996119I’m just replacing one choke with another, and adding some protection components that won’t normally see any current.There is no mains frequency transformer, it’s an SMPS. It’s outputting 12.5V, so it’s good.Don’t know if it always hummed, it’s 2nd hand. My guess is yes, but that I’m using it with lower amplitude input signals (my diy line level output is kinda low, the isolation transformer can bump that up by 3dB) with a quiet computer and the volume turned down and notice the hum more than normal.
>>2996121With the bigger choke in place, the whine is basically gone. I'll still want to scope that power rail to see what kind of transients I get though. The hum mostly goes away with grounding, though oddly enough the volume of the remnant hum increases with decreasing volume. That sounds to me like a signal coupling to one side of the potentiometer, such that the pot being all the way to zero volume means the signal has the highest impedance, and hence is more susceptible to noise. If there's an amplifier right after the high impedance node then it liekly wouldn't matter.There's a wire coming from the main body, and that wire has on its end a little box (>>2996102) with:>the green male TRS cable that goes to the PC>the volume dial>the power button>a TRS headphone output socket>a green power LEDSince there's an LED, there has to be power in that end dongle, which might be where the noise is coming from. Clamping a ferrite around that cable didn't do anything, but it's definitely a possibility that I can add a bigger cap in there. Maybe there's an amplifier inside this little box, but maybe the power feeding the box is causing more noise than the amplifier is mitigating.>>2996119>replace the 3.5mm cable with a 3.5mm jack and use a new patch cable.May well be worth doing. I like the convenience of having this dongle where I can adjust volume and turn it on and off remotely, but redoing it all might be the way to go. A volume knob and power button seperated, on shielded cables if they're to be placed elsewhere from the main enclosure, and a TRS socket each for headphones and the PC (maybe RCAs). First I'll see if I can fix it as is, but even if I can I would prefer a box that cables plug into, instead of a box with permanent cables coming out of it. Hence the IEC socket instead of a hard-wired cable.
>>2996088Hot glue can be removed pretty easily with a drop of isopropyl alcohol, but you're right that silicone is better for a permanent solution.
>>2996118The pot and switch are mechanical devices that wear over time. Sometimes it's dirt on the wiper, other times it's loose solder joints or broken leads. A bad ground connection can cause noise.
>>2996124No amplifier, so the long unbuffered wire with audio and power next to one another seems likely to be the problem. There is the 12.5V rail so in principle I could add an amplifier, but it’s single supply and the pot is ground referenced, so I’d need high-pass caps on its input and output.Moving the volume knob (50k) to be on the box itself is probably the most sensible way to go. Same for the PC input and power button.
>>2996238The pot sits between the signal input and output to the amp. You can buy patch cables with an inline volume pot.
>>2996242That might be the way to go, just ditch the volume pot and put a TRS socket on the box directly. Though instead of buying an off the shelf cable, I'd make a little box with an input and output socket, a volume pot on the front, and clamp it right next to my audio mixer box under my desk. Having an accessible power switch is less of an issue.
>>2996256Well, I’ve added the isolation transformers to the line outputs of my audio mixer (had to cut the back plate and print a bracket to hold the two plates together), the mods to the speaker system will have to wait until I procure more components.I really should replace that ferrite toroid with something less prone to saturating.
>>2996280
>>2996281Ok, if all goes well I’ll be putting a TRS socket in place of the wired remote, and a power switch with built-in LED in place of the mains input. Then an IEC socket will get screwed into the MDF housing directly.And then design myself a volume control box to clamp under my desk next to my mixer.The power switch is just an enable signal to the power amp, I guess it’s safer for the electronics to stay powered up so any audio signal going into them will be within its rails, though leaving an SMPS like this on 24/7 isn’t ideal. My audio mixer is already powered from USB, I should probably make another USB-powered relay so the speakers are only powered while my computer is on. Did the same for my amplifier running off my TV.
I'm designing a kind of display panel with lots of LED lamps for a game. Instead of dedicated MCU I'm using a chain of jellybean shift register chips for driving the lamps. There's also a 7-segment display which has its own control signals. Turns out I overestimated the number of required registers and I'm left with two unused chips. I'm torn between redesigning the board (without registers 6 & 7) or just adding some extra LEDs. Bottom right has some unused space which might fit a LED bar graph or something..
>>2996349You could make some LEDs multi-colour, like those 4-pin RGB LEDs.Post schematic.
I got a few of these and I'm having trouble soldering good joints on the padsYes I'm using flux, iron temp should be okDidn't have as much trouble with cheaper phenolic paper perfboards
>>2996355Scuff the plating with fine grit sandpaper and clean with isopropyl alcohol.
>>2996355They have plated through-holes, which require more heat and solder than single-sided boards. In practice this will mean you need better thermal contact to the pad, lmao if you’re using a conical soldering tip instead of a flat-head, like my beloved D24. Having some solder already on the tip will improve thermal contact, allowing your iron to make joints faster, and makes shitty tip geometries a bit more forgiving.But they’re definitely more resistant to delamination.
>>2996360I don't know how it compares, but green scotchbrite works too
>>2996354Nice idea. In fact I've thought about using 3-pin red/green LEDs instead of bipolar red/green. That would remove the need for 5xNAND chips for driving them red/yellow/green.
>>2996437Half of the register chain
>>2996439And here is the bipolar LED drive thingy. The idea is to generate the clock signal with MCU timer. Then the duty cycle can be changed in software to fine-tune the red/green balance when outputting yellow (if necessary).3-pin LEDs would help to get rid of this complexity, but would require a few more resistors to tune the red/green colour balance.
>>2996440> resistors to tune the red/green colourOr just drive them all at the maximum (e.g. 20mA per LED, or the shift register max current /8) and strobe them in software to sort out the colour balance. Though through shift registers that will prove a bit of a pain, so I’d probably go out and buy a 3+ leg LED and test with different resistors.It’s your choice if you don’t want to do a redesign, but my design principles:>don’t leave for software what would better be done in hardware>a simpler circuit that is preferable, all else being equalWould definitely lead me to do so.It’s easy to get down the rabbit hole of sunk cost fallacy, feature creep, and “first concept bias”, every so often you need to take a step back and think about how your design answers the design requirements, and what compromises it makes. I mean maybr one of your design goals is to use a whole bunch of shift registers, or to demonstrate an unusual LED driving method. I’m definitely guilty of designing projects around obscure components like vacuum fluorescent displays or lots of shift registers, not that I completed either of those projects. The more complex and obtuse a project is, the more likely it is to become abandonware, managing motivation may or may not be a problem for you and your projects.I’m currently feature creeping the hell out of a temperature humidity sensor. Pray for me,
>>2996441>I’m currently feature creeping the hell out of a temperature humidity sensor.How?
>>2996442A crypto miner, and a 3 billion token LLM.
>>2996481That's a lot of tokens.
>>2996442Well it’s gotta be inside an airtight enclosure, so to get power to it I’ve got to use wireless power transfer, using a pair of coils with alignment magnets. But then I want it to track the temperature and humidity outside the enclosure too, so I’ve got to somehow send the I2C signals from another sensor through the transparent plastic. I think I’ve figured this out, you can run I2C arbitrarily slow so long as the edges are fast enough, Schmitt comparators on the photodiodes/phototransistors will sort that out. Then I need a display on the inside, showing a graph of the past data, especially absolute humidity over time so I can see to what extent the contents are offgassing or the seal is leaking. To see absolute humidity I need to calculate a psychrometric chart, already did this with a lookup table and a really crusty linear interpolation and it works.At the moment I’m trying to select a screen. Preferably an LCD so it’s not always lit up like an OLED (may not be a problem), and with multiple colours so I can display concurrent overlapping graphs. I kind of want a round display, to match the circular aesthetic of the charging coils, but displaying normal graphs on a circular display wouldn’t look very good. Unless I made the graphs radially drawn around the perimeter of the display.
Why is there so many types of cartridges? Which one is the best?
>>2996542>D24 for standard THTs>M4 metric thread for heat-set insert dies and those wide multi-pin tips>D12 for SOICs and 0603s (works ok on TSSOPs and QFPs and 0402s)>D52 for meaty THTs and SMDs like XT60s and D2PAKs>D08 for finer SMDs (my cheap T12 ones don't have a very well defined geometry and seem to be worse than a D12)>JL02 for really fine work that doesn't need much power (and stabbing yourself on your soldering iron stand)>C4 for adding solder to a flat surface for no reason>BC2 for drag soldering (I think JBC do concave chisel tips that hold more solder, idk I don't drag-solder)I own the first six, in order of how often I use them, along with K tips that I've stopped using for soldering, and a B tip I've stopped using for heat-set inserts. K tips are just D tips but with less range of motion, they're kinda useful for welding plastic I guess? Conical tips are bad.
>>2996572Thanks anon! And can you comment on why there's all these cartridge types (T12, SI, etc). Just because they want to control it?
>>2996671Each western manufacturer has their own type because there are no standards. Then the Chinese started using western cartridge formats as standards for their own irons, and modifying those standards to make new standards. T12 was probably the first to get copied, then I believe Miniware modified it with a flange and shorter length to make the tips on the TS100 iron. Then those got modified to be shorter and with a lower element resistance to give higher powers, I’ve seen these referred to by multiple names, like ST. The T12 got the same treatment, getting shortened and a lower element resistance for the SH62 iron IIRC, those tips have multiple names no too. Some irons can take multiple tip types, like the Sequre Si012 (Pro), and some stations can be used with different hand pieces for different cartridges.Lower resistance tips allow for higher power at the same voltage, which is important when you want more than 50W on USB C 20V. Or getting more than 8W out of a 1S lithium cell in a cordless iron. Shorter tip-to-grip distance is also generally considered to be a positive, especially for finer work. Hence the direction of modern tip evolution, and the more recent popularity of the JBC tips. JBC do the 115, 210, and 245 families ranging from tiny to moderate size and low to massive power ratings respectively. In principle, a T245 cartridge can handle 200W power, making it a breeze to blast through XT60s and D2PAKs and other tough situations. If I were picking a new iron tip ecosystem, wasn’t too worried about price, and wasn’t planning on doing any microsoldering, I’d definitely go for T245. And even then I could probably grab a T210 or T115 hand piece for smaller work if I wanted. But it’s also worth considering what models of USB iron are available for what tip ecosystem you’re going with, if you plan on doing portable work, Cheap and Cheerful on YouTube has a few reviews comparing different models. Benchtop stations often can use multiple.
>>2996676Thanks so much anon! I have an iron right now that uses 900M tips and I believe this came from Hakko. I've been having trouble with it and have had it burn my tips. I bought replacement tips but something is still wrong and tips just overheat. So, I've been looking at a new iron.I came across a guy on YT who repairs consoles and he uses JBC irons. He raves how great they are etc. I looked into them but they're like $1000. No joke. They're that much. I was floored. The guy did mention that cartridge irons are much better than these with interchangeable tips because they're more precise and also heat up much faster.So I've been looking at getting a new iron with cartridge style tips and got lost in all the types. From reading a bunch of articles, I think I came to a similar conclusion as you that C245 is the best all arounder (not sure if C245 == T245 tho).>Sequre Si012 (Pro)I came across this one in my research too. I like it and it's cheap. It uses SI/IS/T12 which is OK given how cheap it is. I might go with that.
>>2996679T245 is the Chinese name for the C245 from JBC. Yeah don’t buy from JBC if you have money to burn. The Chinese irons using the same tips are decently priced, maybe 30% more expensive than T12-style.With the Si012, or any other 20V max USB iron, note that you won’t get more than 50W on a USB C supply when using 8 ohm tips like T12 tips. The shorter TS tips are a lower resistance and can go up to 100W I believe, but the variety of soldering irons and stations for those tips isn’t as great. Same goes for the SH72 tips, though note that the Si012 can’t use those. Some portable irons have a DC barrel socket at the back, allowing you to use a DC power brick.I bought an M2 thumbscrew for my Si012 Pro, makes swapping tips quick. Had to cut it shorter and file part of it narrower though. The non-Pro model needs you to manually take it apart and swap parts around to change from TS to T12 tips, and the Pro Max or whatever has a pink PCB and RGB lights. The Pro is what I’d get. Also consider the Pinecil if you’re in the USA, or an iron that goes up to 28V if you might need the extra oomph.
>>2996296It's back together now, temporarily with the old wired remote with a 3.5mm plug on the end. Silent unless you hold the speaker right up to your ear, quieter than my PC in standby, bloody brilliant.>>2996679Sounds like your temperature regulation isn't working properly. Dodgy thermistor, wires, power transistor, or possibly feedback circuit. My T12 station (KSGER brand, aluminium housing, internal PSU, and slim blue handle) once had its MOSFET die short-circuit, which roasted my K tip to the point it glowed. Found schematics reverse engineered by russians online, desoldered the SMD P-channel MOSFET and soldered wires to a THT P-channel FET bolted to the case. Works perfectly fine still. So does that tip, somehow. There's something to be said for test equipment that you can get a schematic for. I'd rather have something that breaks every year if I can fix it in a day, compared to something that breaks every ten years and I can't fix it. There's also open source firmware for these stations. Though if you do get a T12 station, don't get one with an integrated PSU, the chinky PSUs are of dubious quality and cut it close with clearances.
Aww yeah. And the red LED is bright enough that I won’t forget to turn it off.
>>2996693>With the Si012, or any other 20V max USB iron, note that you won’t get more than 50W on a USB C supply when using 8 ohm tips like T12 tips. The shorter TS tips are a lower resistance and can go up to 100W I believe,Most of the stuff I work on doesn't require 100W. I work mostly on SMD and often on THT stuff. I've never worked on RF stuff so being able to solder antennas and other kinds of plugs is not something I really need (I presume that's what these high-watt tips are for) If it can handle game console stuff that's tied to ground planes I should be OK.Good to know about USB-C. I've noticed the iron you suggested has a DC power jack too which has no USB-C limitations.>I bought an M2 thumbscrew for my Si012 Pro, makes swapping tips quick. Greta tip! Thanks. I'll order this iron + screw from China directly since I see they're ridiculously priced on Amazon.>>2996703>I'd rather have something that breaks every year if I can fix it in a day, compared to something that breaks every ten years and I can't fix it. There's also open source firmware for these stations. Though if you do get a T12 station, don't get one with an integrated PSU, the chinky PSUs are of dubious quality and cut it close with clearances.I'm with you on the schematics but I don't have a second iron so to properly fix this one, I need a second one anyway. I'll figure out what's wrong with it and will fix it.
when upgrading the NAND flash storage of iphones, why do they mill the chip off??
>>2996833I'd guess it's less likely to damage the board compared to attempting to desolder it. Perhaps they glue the chips down, requiring excessive heat or force to desolder. Or maybe just quicker and requires less skill, and so is cheaper.
>>2996836it's gotta be something about excessive heat damaging components around. I'd think that CNC milling requires way more skill than doing the chip-off with hot air. If you're few microns off, you can easily destroy the pads.anyway, weird af. never seen this before. was watching some random vid in recommendations and it was some guy from china doing a phone upgrade to 2TB.
>>2996838>skillOnce you have the g-code perfected, just clamp the phone into the precision fixture and press the button. Maybe baby-step the Z with the help of a digital microscope.
>>2996833do they mill them the entire way or just enough to reduce the thermal mass to make desoldering quick? do you have a link?
>>2996880>>2996880>>2996880NEW THREADMIGRATE PLEASE
>>2996872>do they mill them the entire way or just enough to reduce the thermal mass to make desoldering quick? do you have a link?https://www.youtube.com/watch?v=2EyI3mwpr18 they mill it almost the entire way. only few microns are left. the amount of precision needed is insane and a damage to pads is probably common if you haven't done it hundreds of times.
