Thread arc-flashed: >>2855842>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.rs/>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:EEVblogW2AEWMoritz 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
>>2862970If you made a pyramid out of copper sheets for the top load, how would it affect the output?
My piece of shit cat peed on my Wii (don't know how long ago).I see corrosion mostly on the ground plane surrounding the main board and around the ports. Not so much on the rest of the PCB.Might be salvageable?Fucking disgusting taking it apart. The thing reeks.
>>2863038Better pic of the PCB
>>2863038>>2863040Clean it with vinegar and rinse it with isopropyl alcohol. It'll be fine.
>>2863038It just means your cat loves you.
>>2863038>>2863040Holy hell, did your cat drench the damned thing? First thing you need to do is clean the boards with 90+% IPA ASAP so as to limit the chemical damage. As for the chassis, wash it in a sink or bathtub with dish soap and the hottest water you can, and then follow up with pet urine remover.
>>2863060It was in a cardboard box that the cat decided to use as a litterbox for who knows how long. Could be weeks. Also got some on my original gamecube controller but that wasn't hit so hard so I think it'll be fine. Chucked the shell and buttons in some enzymatic cleaning solution and the smell is gone. Wiimote might be toast though.I'm not sure it's worth the effort to clean the wii vs just getting another used one. Doubt the stink will ever go away. Bet they're starting to get harder to come by at this point.
https://www.youtube.com/watch?v=04t7hLMj1V0
>>2863038>Might be salvageable?No. Smell isnt going anywhere.This is what you get for owning a c*t.
How can I make an inductor with a 1.5nH inductance?I need it for a radio bpf
>>2863148use an online calculator for an air-core solenoid to get you in the ballparkstart windingthen make an rlc tank circuit with a big film capacitor and small resistor, give it a square wave impulse, and measure the ringing frequency on your scope to figure out the exact inductanceX2 mains caps are good
>>2863165im broke i dont have an oscilloscopeis there another way?
This is a battery for the PS5 controller Somehow that white wire has come loose and slipped out Is that it for this battery? Death? I see no way to open the plastic casing. I genuinely don't even know how it happened I wasn't even pulling this portion
>>2863211Break plastic around the connector (maybe with iron, maybe with snips) and solder wire back. But probably wire isn't even needed. And if its required, it's probably a thermistor so you can probably replace it with 10k resistor or whatever between it and ground.
>>2863212Thank youI think the wire is neededThe controller just blinks an orange light without it and won't turn on. I'm not good with electronics desu, what do you mean by breaking it with iron or snips? The stuff about thermistor and 10k resistors is unfortunately completely above my headSide question, if I can't fix this battery, is getting any random cheap Chinese one fine or should I look for an official one?
>>2863213>what do you mean by breaking it with iron or snips?Break the plastic around the pad and just solder it to the connector.>The stuff about thermistor and 10k resistors is unfortunately completely above my headUsually batteries have a thermistor inside of them. Its used to monitor temperature of the battery.You can bypass it by having an external thermistor or just a resistor, so controller thinks battery is constantly at 25C. I.e. connect 10 kOhm resistor between white and black wire. You probably don't even need to solder anything as you can probably jam said resistor (pick a small one, like 1/8W 10K, you can buy kit of resistors for like $2 or less) straight into connector. Like on pic. >Side question, if I can't fix this battery, is getting any random cheap Chinese one fine or should I look for an official one?Chinese batteries usually have less capacity (and they lie about it) but should work.
>>2863205If you can measure frequency with a multimeter, then you might be able to make an oscillator with a known capacitor to measure. A Schmitt trigger oscillator with an LC low-pass filter as its delay element should do the trick. The tricky part will be getting the frequency low enough. An arduino could probably measure that frequency with some precision. Even if its clock frequency isn’t many times faster than the oscillation frequency, you could oversample and use some clever math to determine the real frequency, assuming it’s constant.If this is for radio stuff, troubleshooting any problems you encounter without a scope might be frustrating. Do what I did and get yourself an old surplus CRT scope from a university.
>>2863064>Bet they're starting to get harder to come by at this point.They're not, genuinely, have no fear anon. They're one of the most widely produced video game systems ever, over 100 million sold, with brand new ones in production through 2013 and sold as late as 2016. You can consistently buy pre-owned Wiis in the $20 - $50 range depending on condition and included accessories. A particularly nice one with lots of extra shit barely goes for $100. Checking eBay, they're currently averaging 400 good, working, used Wii consoles sold per day, or 12,000 every month, with an average bare console price around $30 and complete console price around $60.
r8 my solder job, created an analog volume adjuster, works perfectly BTW
This yellow shit on my capacitors They leaking or is it some kind of adhesive?
>>2863358That's adhesive. I've been told it's bad stuff and should be cleaned off, ideally before it gets old and crusty, but doesn't indicate a bad capacitor. I've no idea if that's true.
>>2863356Kinda gunge soldering, but it's what you expect with dotboard. I guess it's a stereo signal being stepped down by a dual-gang pot, but I can't see wires going to two of the three pins. Looks like it's just a series resistance, not a resistance to ground. Also you used the left-most pins, so I think you'd end up with clockwise = quieter, which isn't what I'd usually want.
>>2863271Yeah there's so many Wii's out there you can get them for free. Someone recently just gave me one even.
>>2863356Bleh, awful. I like it.
>>2863224Thanks for the responseWould it be dangerous to break the plastic? How would you suggest I do it please? Sorry if it's a stupid question, I'm genuinely not sure and have done dumb stuff before when assumingAs for the resistor, funny story. I could get the battery to sort of work somehow by just placing the white wire in it's slot and hoping it stayed put. In the adjusting, the black wire is now disconnected too. Would I use 2 resistors? I do know how to do basic soldering so it's not a lost cause hopefully.
>>2863366Yeah its L and R channels going through a variable resistance, the ground is just passed through. Also I got a reversed logarithmic pot, where the first part of the turn is the mos sensitive, so I wired it backwards to get finer control at louder volumes (lower resistance).It was really hard to keep all the tiny wires in place while soldering, so I just kept it next to the joint and let the solder flow onto it.>>2863371ty
>>2863383>Would it be dangerous to break the plastic?If you're not retarded, safe. If you fail and cut into battery itself (which is very hard) - small fireball.>>2863383>As for the resistor, funny story. I could get the battery to sort of work somehow by just placing the white wire in it's slot and hoping it stayed put. In the adjusting, the black wire is now disconnected too.>Would I use 2 resistors?You know what, just buy a battery
>>2863404>It was really hard to keep all the tiny wires in place while solderingnoob mistakeaccording to soldering bible, you always need physical bonding before any solder is appliedas shown in the pic, except you dont need several turns, just 3/4 of one turnwhich means you dont need to have 3 hands, each holding solder, iron, and wire(took a while to even find a reasonable pic to show coz the internet is flooded with the retard/noob implementations)
>>2863383>suggest I do it please? Sorry if it's a stupid questiontearing things apart is something you shoulda learnt in your early teensas an adult with tools, best thing to use is side cutters, as they get into tight spaces and are very sharpalternatives: end nippers, knives, files, dental picks, long-nose pliers, dremel grinding or cutting wheels, nail clippers, soldering irons, big nails heated on the stove, hacksaw or coping saw blade wrapped in tape
>>2863460> picrelAt that point shown, you don’t need to solder.Mechanically sound connections are also electrical code.I see lots of things basically what we called “tack soldered”> but smd is…yep. I love opening things and find out the rattling noise is a resistor that desoldered itself and fell off the board into the case.
>>2863468> nail clippersI’ve just been using random nail implements for wire cutting ever since I found out copper wire has about the same hardness as a fingernail.my wife is probably still looking for the missing tweezerman nippers, lol.
>>2863460>wire wrapThat's how computers were prototyped back in the day.
>>2863447>You know what, just buy a batterykek come on anon, have faith in meThat said I have cut into a battery in the past. But still, have faith. I just thought the plastic casing was there for a reason and couldn't just be torn apart like that. I got this far just messing with it. It just bothers me because there's nothing wrong with this other than a few loose wires>>2863468Thanks, I have some of these. I'm used to tearing things apart but it's doing it non destructively where I wasn't sure. I guess I can use the side cutters to pry off the plastic which hopefully creates enough space to solder the wires back. It just seems it'd be quite fiddly even after that due to the limited space to get the iron into
>>2863497> wire wrap for prototypingNot for prototyping. It was a pain in the fucking ass to re-do a wire-wrap connection, especially if it was the first one on the pin, and there was two more that followed it.It was for low-yield production. i.e. back-planes for custom computers.Trivia: as far as I remember, OK Industries also made some of the first solderless breadboards.
>>2863502>It was for low-yield production. i.e. back-planes for custom computers.aka prototypeshttps://www.youtube.com/watch?v=BaTjwo1ywcI
>>2863513>aka prototypescommercially available products you can buy at Sears =/= prototypes
>>2863516>Merry Christmas, Billy!I demand a refund.
>>2863519You joke, anon, but I actually got my wrapping tools as a birthday present.
>>2863521At least you didn't get a TRS-80. The wrap tool is more valuable. lmao
Idk if this is the right place to ask but are analog synthesizers filters fixed frequency? As in, will they attenuate the same frequency range if a low C and a middle C are passed through them, or will they somehow shift the range to compensate.
I'm having a nightmare of a time with this, can anyone help? The 3 pins snapped off on the right side of the image, leaving then poking through both sides. I managed to remove the first two by heating up the area and wiggling the pin freeThis last one is tiny and simply won't budge anywhere. How do I get the pin out? Other side looks the same, I prob should have pictured that though
>>2863546Add more solder. Just do it.
>>2863551I triedI even added more fluxAt this point I'm worried I've killed the board or something because no matter how much shit I try it just won't come loose. This is the other side
>>2863531their operation is typically fixed frequency, yes. to make them "shift range to compensate," you need a voltage controlled filter (VCF), and the same CV (control voltage) that gets sent from the keyboard to the VCO (oscillator) to make the pitch also gets set to the VCF to control its cutoff.
>>2863559The pin is stuck because it's attached to the ground plane of the PCB. You need more heat in a shorter time which means either a more powerful iron/larger tip or hot air.
>>2862970if a PTC is rated at 1000V is it safe to assume that it will thermally withstand 1000V without blowing up? i guess i mean to say, what exactly is "1000V" referring to: some sort of dielectric strength breakdown or its thermal capacity?https://www.vishay.com/docs/29072/ptccl.pdf
>>2863564Thank youThe only other iron I have is a cheap Chinese one which does get hotter but I've never used it I don't thinkWhat should my method be for taking it out then? Just continue heating up one side with copper wire until it drops out?I should mention the pin is bent in there as well
>>2863571Use the hotter iron and a large flat tip if you have one. Secure the board in place, add flux, ensure there is enough solder on the tip or the joint to transfer heat properly, then heat the joint and use tweezers to pull the pin out or use a paperclip to push it through. Make sure the board isn't sitting on a surface that draws heat away from your iron too.
>>2863571>What should my method be for taking it out then?the easiest way to get that pin out is to leave it the fuck alonewhen you pop in the new part, the 2 pins in the holes are more than enough to secure it in placethe third pin can be bent around and soldered on top(i learned this from replacing transistors: it's a lot quicker to cut the legs, and solder to those legs, than to remove the PCB to desolder from them from the bottom)
>>2863573Bloody hell, finally. Thank you very much, worked a charm. Now the fun is seeing if any of my repairs or indeed, the board itself even works because I tried so much shit that I tried that I might've borked something completely up somewhereOh well though, learning experience if so. >>2863599The pin was sticking out on both side though, I could get the new part in without getting rid of it
>>2863500Dammit now I have a new issueI reconnected the wires to the battery board. Tested the battery, it worked. Happy days. Then I left it for a while and later cleaned it up the board a little with some isopropylNow I'm putting it back together and the battery is no bueno again. What could I have done wrong or changed? When I connect it, the dualsense flashes blinks an orange light twice, which supposedly means a battery issue. But I don't understand why it's giving me an issue now and didn't before. Any ideas?
>>2863601>I tried so much shit that I tried that I might've borked somethingIf anything you might've broken a trace which can be bodged easily. In that case you carefully scrape the green solder mask away from the remainder of the trace and tin it, then bodge to the pin. You can use wire from a ribbon cable or a strands from copper wire painted with nail polish or covered & secured with tape.
>>2863603Is it charged? Maybe it discharged while you were power washing it or something.
>>2863608Well without the battery working I don't seem to have a way to test it. I'm not sure what happened. This shit was working fine beforeHow would I know if I broke a trace though? >>2863608Kek, it's not a charging issue because it doesn't charge. It jsut blinks orange which is what it was doing when the wires were disconnectedThen it stopped doing that once I connected the wires backThen it started doing it again after I replaced this potentiometer >>2863571The thing is, I don't know if it's something in my repair or if it's the battery again.
>>2863570>what exactly is "1000V" referring toobviously, you cant put 1000V across it when it has a resistance in the 100's of ohmsso it must refer to the voltage which, if exceeded, would allow electrons to fly out of it into neighboring parts
>>2863618>How would I know if I broke a trace though?Use a multimeter in continuity mode. Put one probe on the pad and the other probe at the end of the trace. If it beeps then it's connected.>I don't know if it's something in my repair or if it's the battery again.Probe the battery terminals for voltage and follow the power trace until you don't get a reading anymore.
>>2863622>Probe the battery terminals for voltage and follow the power trace until you don't get a reading anymore.I'm too thick to know how to put this into action anonI've also never tested something in continuity mode, I'm pretty new to repairing things in general which is why I don't mind mistakes but I'm not exactly sure what I'm doing. Probing traces sounds simple enough though and I've seen it before, but I'm not certain how to do it on the controller
>>2863634Do you have another controller that you could borrow the battery from to test? Maybe the USB port loosened from the PCB while you were removing the pin earlier. Look at it under magnification and gently wiggle the port to see if there are broken solder joints.Other than that you should watch yt vids of people using a multimeter to find faults. By the sound of it the problem is a bad connection somewhere, maybe in the battery pack.
>>2863642I'll try testing that later, I do have another controller that I'd have to open. Good idea thanksShould it work, then I'd be perplexed because I don't know what's wrong with the fixed batteryBut if it doesn't work, then I'd have no idea where to really begin with a diagnosis. I have seen people using multimeteres but generally I just copy and there doesn't seem to be much for the dualsense specifically. As for the USB port being loose, you mean the charging port? I don't think that's it because I get the blinking orange lights as soon as I plug in the battery pack, even without a cable. It's exactly what was happening when the battery wires were loose, then I fixed it, did further modifications on the controller, and suddenly it wasn't working again
>>2863646My reasoning is that the power light blinks when you plug it in so there is functionality to a degree, but because it isn't charging there could be a broken trace or solder joint that prevents the charge circuit from functioning. What happens if you connect it to a PC with a USB cable?
>>2863647Nothing seems to happen, it doesn't get detected on gamepad tester eitherIt doesn't seem to just be the charge circuit because I know the battery does have charge, it doesn't turn on at all. I tried to look online at what double blinking orange lights mean, but the answers weren't clear. Some say it's a battery issue, others say it is due to a short. But I was getting the same issue before due to this battery, and if I shorted something I can't think of what it might be and I'm not certain how to test. I will confess to something stupid. At one point a not small blob of solder fell off my iron and onto the board. I immediately picked it up with the copper wire, and it lifted up all in one piece, but it was pretty bad. Could my board be dead because of that? I rechecked the whole area compared to a scan of the motherboard and nothing seemed untoward. Tbh I'm still leaning on it being a battery issue, only because it matches the issue I was having before with the battery.
>>2863651>Could my board be dead because of that?If the battery was disconnected it should be okay, but check the area closely in case you missed a blob.
This is a very naive question, but electronics isn't my area of expertise:Is there a circuit/component that could work as kinda of a fixed value storage?The idea is that if a voltage is applied to it you'll be able to read a specific value, the format of the value not being that important as long as there are like 50+ distinct values.I guess it'd be somthing like a PLA but preferably more scalable and less flexible.
>>2863658Yeah, things use that all the time, and other complicated, related things like quadrature amplitude modulation.The easiest thing to do is have a capacitor hold the value. When you read it, you want a very high impedance voltage reader, like a JFET.Check out “sample and hold” circuits.
>>2863660I see, that's probably too complex for what I'm considering. I'll shelve it for now, but thanks for the response.
pulse position modulation
>>2863531Fixed frequency, yes. Conventional analog filters typically have a pass-band, say from 0-500Hz for a low-pass filter, then a rolloff at some multiple of +/-20dB/decade (6dB/octave). Some filters might level out after this rolloff, others keep going down. Generally we assume anything below an attenuation factor (e.g. 80dB) is in the filter’s stop-band.There are some filter topologies that might suit what you’re after. A “comb filter” has a frequency-domain shape that repeats in the harmonics of a chosen base frequency, which could hit 440Hz and 880Hz, but it wouldn’t jump to 1760Hz and 3520Hz, but also fill in 1320Hz, 2200Hz, 2640Hz, and 3080Hz.I’m general, I wouldn’t fuss too much over making your sound static. Having a timbre that varies across your musical scale adds dynamism to your instrument.>>2863618Freshly soldered wire probably broke off in there. Resolder and cover in epoxy or hot glue.>>2863658A memory chip? Parallel or serial EEPROM chips are fairly easy to interface with, but it is a fundamentally digital process. If it’s just one value and an analog output is fine, then a digital potentiometer IC isn’t a bad idea, but to set a certain value you’d need digital pulses. Arguably you could do this with an oscillator and comparator, to step up and down the pot when its voltage output is different to some input analog voltage.
any suggestions for a good solid polarized DC power connector with a locking mechanism?
>>2863733>suggestionsdunno if they qualify as "locking" but these magnetic pogos are kawaii as fuck
>>2863733Amass xt60 locking.It’s like a standard. You could also ask /rcg/
>>2863733Dsub 2W2 or 2V2Aviation/microphoneM8Deutch if you want waterproof
>>2863759>>2863784cringe and cringe!!!7w2 connector
>>2863806They are objectively the best connector I agree, but if the anon ONLY wants power, a smaller connector is probably nicer. Not that I wouldn't recommend adding communication between source and load.Also the 9W4 is a better connector for when you have more than just a positive rail and ground.
>>2863784>>2863806>>2863810You missed the point that OP wants a Locking DC power connector.
>>2863821Yeah, it's got thumbscrews. Extremely secure.
>>2863655You were right, thank you. There were blobs near this black connector. I didn't see them yesterday because I was operating in shitty light and didn't notice.. Daytime has made it much more apparent. Two things though I need help with please.How do I remove this excess solder without damaging the plastic port? Is it just the same copper wire procedure? Some of it just scraped off when I cleaned the area but it's largely still there, and I'm worried I'll burn the connector or something. Secondly, considering I already connected the battery to test, could I have killed the board already with this mistake?
>>2863921Apply flux to the blobs first. Clean your iron's tip so it's totally free of solder, then carefully touch the blob with the iron. Add more flux, clean the tip again and repeat until the blob disappears. Don't set the temp too high and don't dwell on the joint for longer than a second each time.The idea is to wick away the excess solder without using desoldering braid because braid can cause more problems if you're not careful (lifting traces, removing SMD components, etc).
>>2863943>without using desoldering braid because braid can cause more problems if you're not careful (lifting traces, removing SMD components, etc).That's kind of what makes me worry I screwed something up elsewhere.I've been relying on the copper braid to both try desolder the stuck pin, and to desolder the dropped solder. I wonder if somewhere along the line I did mess up an SMD component or lift a trace. I'll try what you said though, thanks. Would the plastic connector not burn with my solder iron coming into contact with it though? It's not clear in the picture but it sort of extends a little underneath as well so I can't just keep it away. My flux is also really shit and is some sort of hard gel in a tub. It's always annoying to apply, I kind of just dip my iron into at points to soften it and then lift it with something else. Picrel is the state of the connections after I struggled to get that pin out in case it shows any major issues
>>2863948The pads look to be intact but the right joint could use a touch more solder, unless I'm seeing things. As for the connector, the plastic is semi-resistant to heat, so if you work quickly and let the board cool between applications then it won't melt (too much lmao). I recommend that you cover the board with paper and tape so you only expose the area that you're working on, to prevent further accidents. Clean it up with IPA and a cotton swab after.
>>2863948Also, mix some of your flux with isopropyl alcohol so it's usable. Heat the flux so it's easier to stir.
>>2863951>to prevent further accidentskekI do have electrical tape but I would hope I can avoid anything major like that. I did use a little copper thread earlier to do a little cleaning, but this time I'll clean my tip, apply flux to the area and gently tap my iron against it for a second. I would guess ideally it would transfer the solder onto the tip? >>2863952Good tip thanks. Dumb question, but what should I be using to actually lift the flux and apply it to the board? Also, another dumb(er) question, how do I test my controller battery using a multimeter? With the connector in place I'm just not sure. I did learn how to test continuity at least, but again unsure what specifically I need to test to ensure the board hasn't been dedded by me. I've never used a multimeter before desu
>>2863956>ideally it would transfer the solder onto the tip?Yes, a tiny bit at a time.>what should I be using to actually lift the flux and apply itYou have several options. There are brush applicators, syringes, flux pens, droppers, toothpicks, bamboo skewers, a screwdriver, etc.>how do I test my controller battery using a multimeter?Make sure the probes are plugged into the right sockets, set the meter to DC Volts, put the red probe on the positive battery terminal, and the black probe on the negative terminal.
>>2863956It looks like there are two missing components. One right next to the small capacitor near the connector, and the other at the very bottom-middle (two solder pads).
>>2863962I don't think those are missingDamaged possibly but here's a look at the full board online and it looks about the same.If they are missing or damaged then I'm screwed because I have no idea what to do to fix that.>>2863961Thanks. I've used a metal pick but worried maybe I'd scratch something that way, Maybe I'll grab some toothpicks. As for the multimeter, this is where I'm being dumb. Where are the terminals on the battery?>Yes, a tiny bit at a time.I forgot to mention, I do have a solder sucker. But when I used it I just couldn't seem to get the application right. The nozzle on the sucker is fairly big while the board is really small. Also with the impact the board woudl just sort of shake after I used it and I was never sure I actually did anything. Worth trying again or just stick to the solder method?
>>2863976>I don't think those are missingYou're right. It's all there.>Where are the terminals on the battery?In your pic here >>2863603 where the red & black wires are soldered, and on the plug end where it plugs into the board.>stick to the solder method?Yes. Solder suckers are for clearing through-holes and are probably overkill in this application. If there are blobs that aren't shorting anything then you can leave them.
My shitty multimeter m-830b does not show digits, only dots and HV, no matter what mode I select. I tried different good batteries. Did I kill it or blow a fuse? I swear I didn't measure current in parallel
>>2863995Plug your probes like pic related and turn the dial to V 20 (top left).
>>2863996If it's still shitty then change the battery(ies).
>>2863996>>2863997Tried that again. No dice. All I can see is the dot moving from place to place and blank spaces where digits should be. I tried a bad battery just for good measure and the dot/HV faded out quickly. With good batteries the dots and HV persist. Nothing else is on display.What I wonder most is how I blew it, since it was sitting on a shelf for good 10 years and worked for a few days until suddenly it started doing this shit.Pic related, what I see.
>>2864001Do you have another set of probes?
>>2864001Should add, doesn't matter what I set it to or try to measure, the numbers refuse to be displayed. Even trying to measure a battery so it can show 1.5 doesn't work. Not even a display for open/short circuit.
>>2864003Do the probes feel loose? Are the banana jacks dirty or full of debris? If not, then take it apart. Maybe some battery corrosion or a loose connection on one or both banana jacks.
>>2864002Sadly no, and it doesn't care whether probes are attached or not. the probes did work the day before, only some wonky readings and only if I rotated them wrong.I'm very tempted to buy a new meter tomorrow and scrap this one for components but I want to know what's up first.
>>2864003If you put the meter in continuity mode and touch the probes together, does it beep?
>>2863976 (You)>>2863986I tried, but I wasn't really able to extract the solder. You see the solder on the right side? That's supposed to be there. My problem was I seemingly had a small splodge on the left. Very tiny, but definitely there. I don't know if it even made a different to anything since it was sort of underneath. Anyway, as I tried to get rid of it, I was careful, but I don't have a fine tip, and some of the plastic just sort of burned and covered up the loose solder. It's possible that solder was meant to be there anyway, like I said there's some closeby as is.I know the black connector looks broken here, it isn't. I just hadn't cleaned it up yet.I've also confirmed it's not the battery. Tested the same battery in another controller with no issues. Tested the good battery in the broken controller and same problem.Which means it has to be a short I suppose. A short caused by something I did.But it exceeds my knowledge and skills to know what I possibly could have done. One thing is that I get the blinking lights as soon as I connect the battery to the PCB, without any of the other connectors. It's literally just >>2863976 (You) with the battery inserted, and it's blinking orange lights.I'm guessing it was when I dropped the blob of solder, but nothing looks amiss.Any ideas on my next steps from here plz?I don't want to ripip a controller that was working fine.
>>2864001>sitting on a shelf for good 10 yearsgood chance the switch contacts are all oxidizedopen it up and hit it with contact cleaneror gently rub both PCB pads and springs (on the knob) with eraser
>>2864010Get a bright light and magnification, and look over every inch of the board for problems. That's all I can tell you, Anon. Good luck.
>>2863362Most of the glues used in old electronics aren't too bad, with one exception.Back in the early 80's some Japanese manufacturers used a particular type of glue that with age turned corrosive and highly conductive. Now this is fine if it's only used in a few places and you clean it off before turning the device on, but let me tell you there's nothing quite like firing up a 100w per channel stereo amp and having it blast a thumb sized hole through the PCB because the whole fucking thing is full of the stuff and shorted in every possible way.
>>2864012Is there still hope or is it possible it's dead for good? Considering I have no replacement pieces should anything be damaged, though I don't know if they can be bought. When you say problems, what should I look for? I think I should probably test for shortages but I don't know how.Also does the furthest right connector here look like it has too much solder on and could be shorting or nah? I wonder if some of my spillage got into thereRegardless, I'm very grateful to everyone who helped me itt. I might have killed a controller but I learnt a fair bit at least. Thanks bros. I hope I can fix this.
>>2864011Thanks, I'll try that. Still perplexed how it happily worked at first but then retired itself very quickly.
>>2864018>Is there still hope or is it possible it's dead for good?I don't know, Anon.It's hard to see, but it looks like some pins are bridged with solder, and it's stuck to the plastic. Try to pick it away with a small screwdriver before using your iron as you may not need it. Use plenty of flux if you do. Clean the connector thoroughly with IPA and a brush when you're finished.
fascinated by the design of a cheap garden light. there is a cheap tiny 4-pin controller and the ds is only available in Chinese. appears to be a boost controller / battery charger / joulie thief all in one chip. it doesn't even need a photo element. apparently when it gets dark the chip senses low voltage from the panel and turns the LED on via the battery. these chinese technologies are amazing.
>>2864021>bridged with solder, and it's stuck to the plastic.I think those are just threads from the cotton swab I used when cleaning. My solder blob didn't do that far, but it might have touched the far right connector. I wish I knew where to start or what I was looking for. I really hoped cleaning some of that excess solder today would do the trick, because I think the two pieces near the connector here >>2863956 were actually soldered together which would explain the short easilyI did also mess up the plastic connector for the mic, but that's a minor issue. I seem to have nudged it with the iron and burnt it. Fool to me for working on this in poor lighting last night though. Just wish I knew how to approach it or what I was looking for ;_;
Is it safe to scrub the whole board with a toothbrush and a lot of isopropyl, or could i damage something that way? Feels like it might pick up loose bits of possible solderI did give the whole board a look with a magnifying glass, honestly couldn't spot anything too amiss. Side question, can the crocodile clips of the helping hands damage the a motherboard like this? There might be some excess solder where I've marked in pic, but how would you suggest I take it out? It's in between and a bit further behind the gold connector, which I wouldn't want to damage.I also don't know why it's orange under the very last connector. Is it just part of the board or my error? Can't tell from this>>2863976Same with the little resistor, if that's what it is. It might have a little excess solder around it, but how would I clean that without displacing it?
>>2864008Those shitty meters don’t have a continuity beep. If it doesn’t display 0000 with no probes in it, then no amount of plugging new probes in or resoldering the banana sockets is going to fix that.
How hard is it to design a video card from an EE perspective? Why is fucking Nvidia worth 2 TRILLION? They are no apple, no Tesla, no Amazon, no MS, no Google. They make fucking chips. Input, output. VCC, VSS. and some signals. WTF?
>>2864061>Why is fucking Nvidia worth 2 TRILLION?coz AI is the new shiny thingit's creating a bigger bubble than networking did in 2000'seven fucking Linux had a bubble around that timefools figured they were getting in on the ground floor of another microsoft
I have a vintage korg keyboard. It all seems to be working except when on one specific instrument setting, which is producing gnarly static when keys are played.Could this be something simple like a grounding issue, or do I need to start learning electronics
>>2864061>How hard is it to design a video card from an EE perspective?not too hard. unless you mean a cutting-edge NVIDIA gpu, in which case its unfathomably difficult. take a look at the Vulkan standard. this fucker is over a thousand pages long, and thats just ONE of the APIs you need to support, to say nothing of the actual implementation. and dont forget CUDA support, too. oh, and youll need some HDMI and DP controllers on there. and a PCI-e controller. and a memory controller, specifically the fancy new ones that allow for direct CPU IO. and once you got all that down, you gotta get it up to 80+ TFLOPS. good luck!
>>2864079If you look at a graphics card, it’s basically the GPU and a bunch of support chips that takes the 12 V and turns it into 1.1 V at 100 A or more.
>>2864098well yea, but OP was asking why NVIDIA is worth 2 trillion, and the answer isnt because they make graphics cards, its because they make GPUs. i assumed he said graphics card when he meant to say GPU.
>>2864078Probably not grounding, but it might be something simple. In particular, I’d look for bulgy or leaky electrolytic capacitors, or just the selector switch itself. Spraying some contact cleaner or electronic cleaning solvent into the switch and moving it about a bunch is usually good enough to clear any gunk that might have accumulated inside it. Slide switches are especially bad for this. The same goes for any potentiometers (rotary or slide) that are specifically associated with this one instrument setting. If it’s more digital than I’m assuming, it could be that it has corrupted memory, in which case you’d have to hope that someone has uploaded the ROMs somewhere. That or you can read your own ROM chips, interpret the bits and bytes, then use context to find a flipped bit or two to reprogram.
>>2864078what specifically do you do to select this setting? it could be a dirty pot
>>2864099Nvidia has a big market cap due to hype.Even the VGA… nay… even the IBM monochrome adapter basically revolved around one chip.
am i reading this datasheet for this SPDT switch correctly? i don't really understand the schematic and the pin numbers arent even labeled so im sort of guessing herewhat i'm assuming is that, when not pressed, the pin closest to the button and the common pin are connected, and when it is pressed, the pin furthest from the button is connected to the common
How do you reflow shit with solderpaste in the oven without stencil. What are the tricks?First LED batch soldered fine, but second i had to manually move bunch of them with hot air.
>>2864187>i don't really understand the schematic this is where logic and common sense, if available in your area (not valid in the deep south), become useful because the shaft moves front to back when you push it, you can expect the 2 front pins to be normally connectedthen the 2 back pins become connected when you push it inso, the contacts move in relation to the shaft, even if the intern-produced drawing implies otherwise
>>2864061Even doing a basic one is hard enough. They all have custom CPU/shader architectures to start with. It's more than just generating a VGA signal from video RAM like 30 years ago.The current nvidia hype is because their GPUs are used for data crunching and AI.
>>2864128I've cleaned out all the switches / sliders associated with the static sound issue, so I'm wondering about the ROM now. Am I correct in that I need to be looking for the "EPROM" chip. Sounds like it could be fun. For context I'm working with a korg sas-20. All capacitors seem to look normal to me >>2864162It's a click in switch in a row of switches where whatever one has be pressed "unclicks" when a new one is clicked in. Like a cassette deck controls situation (play/pause/fastfoward/rewind)
>>2864246Ok, I just saw a video of someone properly cleaning a slide potentiometer, and realised I did a shit job. Will be trying this. Need to figure out what these other switches (for the instrument settings) are called because they aren't pots. I'll desolder and see if they come apart at all
>>2864246I found what I believe to be a service manual:https://www.synthxl.com/wp-content/uploads/2020/03/Korg-SAS-20-Service-Manual.pdfBlock diagram, schematics, parts list, and board-views. Probably trouble-shooting instructions too, though I doubt they'd be too helpful. At least it should have a calibration/adjustment guide for all the trimpots in there, which I'd go through before anything else.Seems like it's partially digital, so it could be an analogue problem or a digital one. It's a complex circuit, it has op-amps, BJTs, JFETs, logic ICs, at least one vactrol even. I doubt it would be switches though, as the switches are just doing logic voltages to the CPU. It would likely only be a potentiometer if that pot is being used exclusively by the noisy instrument. If it is an analogue problem, try to follow the schematic to see what else is active specifically for the noisy instrument. Not just pots and caps, but it could be thermal gunk drying out between matched transistors, drifted carbon composition resistors, etc.
If your house already is using the fresh water pipe as the primary bonding/grounding point, does the NEC require that you drive one grounding rod in addition to the fresh water pipe when say you upgrade the panel to a higher amperage?I get it that they do grounding rods on new construction.But if my fresh water pipe, which is metal and is already being used as the ground, am I really required to get a grounding rod put in addition to that?
I'm making a quick and dirty spot welder with 10 25V 3300 uf capacitors all wired in parallel. I have the terminals all soldered to a fairly heavy solid copper wire (from 120V in wall wiring) but I'm wondering if I need to do anything special for the welding contacts and/or the wires connecting them to the capacitor bank. I have some 20 gauge stranded copper wire laying around, would that be good? I know its not going to overheat, but I don't know if I need to worry about limiting the current or not.
>>2864307For how long is the site ground required to carry the full service current on both phases?Think about that question.But, another ground probably won’t hurt, go home depot, get rod, pound, get some of that #6 green ground wire and you’re good to go.
Can't wrap my ahead around this simple schematic. Where is the ground?? I guess the diode in the ground path threw me off. Even LTSpice is confused. I was able to run it like this once but now I am getting a floating node error. Where should I add the ground?? Is it V1 or V2 that should be grounded? LTSpice doesn't like floating power since it needs a ground reference. I think the theory is that if V1 > V2, the diode should be conducting and pulling the base of the Q1 to the ground, and when V2 > V1, Q1 opens. But I have no idea how think about it since I don't understand how to measure voltages on both sides of the diode, where is the reference point?
>>2864341Use + as the ref.Ever heard of negative rails?
>>2864335Three problems:You’re not gonna weld anything but tinfoil with that tiny cap bank.I’m not a guy that advocates crimping over soldering, but in this case you’re gonna want to crimp.20 ga isn’t gonna cut it. It’s not even house wire, which is 14 or 12. Get and use your dads old jumper cables and replace them with a new chinese set made with aluminum wire.
>>2864352only heard of negative rails in the context of a dual rail supply. but inverting + and - with a single supply is just bizarre. i guess this circuit could instead be changed by using a pnp and reversing the diode and moving it up to the + rail to make it make sense.
>>2864341voltage is all relative. ground any node you like, the circuit will behave exactly the same regardless of your choice (save for the voltages being shifted up/down).
>>2864355No, just keep it the same and read off negative voltages as need be. If the + looks more like a common reference rail to you, use it.>>2864364> it’s all relativeExactly. I feel like we just had this discussion, check out the hole flow vs electron flow thread.
Came across left one in pic related.I was thinking of using a Chinese high voltage transformer instead of coil to get my output. How do I tune it to be optimized?I have an LCR to measure my transformer
>>2864341LTspice fucks out if you don’t give every isolated circuit a ground node. That includes secondaries of transformers. Doesn’t matter where it is, but I’d put it on either side of the voltage source so your measurements make sense.
>>2864412Have it in fastid to save your time-tinyurl com 23cuorlv (add dot and slash)
If anyone here has pic related I'd very grateful if you take a little bit of your precious time and measure the total height of MHP50.Official datasheet says 51,5mm, some sources call 37mm.
>>2864354>>2864335I think I may have misrepresented this a bit by mistake. Im making a spot welder to build battery packs, all I'm welding is thin strips of nickle ribbon. Tinfoil is probably closer to what I'm aiming for than what you're thinking of.
>>2862970what's the cheapest way to get a 1000V DC power supply capable of supplying 100 ma? voltage stability doesn't matter, it can be rectified with no capacitors for all i care. my initial thought was a variac in front of a microwave oven transformer and some high voltage rectifier diodes... but i don't have any broken microwaves sitting around.
>>2864465>spot welder to build battery packsif you wanna use caps, you'll probably need Farads rather than millifaradsotherwise, you'll get sparks but no weld
>>2864412>using a Chinese high voltage transformer dont be a difficult childjust do what everyone else has already done, which is to take apart a Kodak/Fuji one-time use camera with flashthey're like $1 at the thrift store
>>2864472An old 12V linear wall wart transformer will give you 1000 V out if you feed it 100 VAC in.I recommend you go lower… like maybe 250 V and step it up with walton cockroft.… wall wart insulation is probably not rated for 1000 volts, that is why.Even microwave ovens double the output wit a single stage walton cockroft.
>>2864472>1000V DC @ 100 mathat's 100W of high voltageenough to kill an elephantgood thing you lack the knowledge to build itit's the only thing keeping the elephants on your street safe
>>2864481I tested it and it sort of worked. The power supply I had sitting around only goes up to 18 volts and the caps are rated for 25 so I have a little wiggle room to bump up the juice. I tried just putting 2 layers of nickel strips together and its a little inconsistent but definitely needs a little more penetration. It does make them stick a bit as is though, but one weld is not gonna hold it consistently or very tightly.I'm thinking I might just order another 10 of these things and add them in to double the capacitance.
>>2864450Don't own it, but the Aliexpress pic shows the bed surface as 50x50mm and the height from base to bed surface as 37mm.I waited 6 gorillion minutes to post this. Fuck you, go0km0ot nigger sellout faggot.
>>2864465Say you have two 0.2mm thick nickel strips, and you need to melt a 1mm^2 area. That’s like 5.5J total, so it’s in the ballpark of capacitor capabilities. You’ve got 10J in your capacitor bank at 25V, which is probably cutting it a bit close, but you’re not more than an order of magnitude away. You’ll want to switch the caps as fast as possible, I’d look into using an SCR.>>2864472100W is in the marginally expensive territory for DC-DC bricks, and very expensive for an AC transformer core unless you can find one 2nd hand. A CW multiplier off mains is probably going to be the cheapest method (not sure about capacitance) but it will be pretty dangerous being connected to mains. I’d look for a 2nd hand DC-DC brick in the 12-24V range and make yourself a ZVS driver with a small/mid-sized toroidal core. A (TL494) boost converter would work too, but you’d need a bigger inductor than a ZVS circuit. It’s also an option to go ZVS off rectified mains, and your transformer gives you the isolation you’d want, but it’s more of a pain to design at that primary voltage.>>2864487>An old 12V linear wall wart transformer will give you 1000 V out if you feed it 100 VAC inTried reversing a MOT like that once, immediately popped the breaker.
>>2864253Cheers mate. Had a good look in the manual and it has a bit in there about hooking up an oscilloscope to read the sine wave for the brass ensemble section and adjusting a variable resistor till you get a clean wave. Brass ensemble is one of the noisy ones. Will try source an oscilloscope
>>2864554Just found out oscilloscopes are expensive. Would there be anything stupid about adjusting the resistor live and playing the keys as I go to try find the right adjustment
>>2864556Not at all, but if there are like 5 things to adjust sequentially it might be really tedious. For single waveform analysis consider buying a cheap DSO138 or similar. They’re pretty shitty, but probably good enough.
>>2864521Love you, bro, guess the 37mm is correct number then. Chinks make very nice products but their spec sheets lack information badly.
>>2864556An USB scope like PicoScope doesn't cost that much and does the job just as good.
>>2864678
>>2864528>boost converteri always heard that boost converters aren't very good with huge boost ratios. ideally this would be done with 12v input so ~100x boost ratio.i did just find these chinky high voltage transformers that claim 60W, which is close enough to my needs. so i might go to the trouble of trying to make some sort of an isolated converter with a tl494.https://www.aliexpress.us/item/3256806241478979.html
>>2864680This is simultaneously stupid/absurd and ingenious and I love it
https://en.wikipedia.org/wiki/Helmholtz_coilhttps://www.researchgate.net/publication/48176965_Helicity_and_a-effect_by_current-driven_instabilities_of_helical_magnetic_fields
>>2864703https://www.nature.com/articles/ncomms9359https://www.nature.com/articles/am2011187
>>2864703>11kV electron beams move at 20% the speed of light0_0
>>2864678I don't know if I'd recommend paying $80 for a single-channel scope, unless you specifically need a portable scope. Either get a shittier single-channel scope for half the price, or save a bit more for a dual-channel scope. Be it a Hantek, a USB scope, or a used CRT scope.>>2864680The 7805 has built-in thermal regulation, but I doubt it's being used here, and it probably regulates to a temperature below the melting point of solder. I wonder if there are high-temperature voltage regulators you could use more easily as a hot-plate?>>2864685You have two options with a transformer converter. Either use it in a push-pull configuration (the TL494 can do this with a centre-tap primary) or use it like a boost converter. To use it like a boost converter the transformer needs an air-gap (i.e. to be a flyback transformer), it's hard to say whether what you have can do that.FYI, if you're using a TL494 I'd use it with external MOSFETs, instead of its own internal bipolar power transistors.
>>2864680https://www.youtube.com/watch?v=ot2PqusOoZ8
>>2864759portable scopes are actually pretty great, and idk of any big boy scopes with digital screen capture that would go for under $50
>>2864793>big boy scopes with digital screen capture that would go for under $50I was thinking along the line of the shitty DSO138s and their ilk. They're toys, but still suitable for the adjustment of the waves in this service manual: >>2864253. Single-shot capture and digital protocol interpretation isn't required for periodic analog work like audio, and even the numerical readouts like frequency, RMS, THD, etc. aren't a hard requirement. And if you do anything more demanding, you'll often want a second channel to compare two coincident signals. If the anon plans on getting into electronics and doesn't need portability, then he should get a CRT or cheap digital scope. If this is just a one-off repair, then a DSO138 is probably fine.
>>2864804idk whether the range is accurate, but $80 for 100MHz is a damn steal. the DSO138 only goes up to 200kHz (l0l) for $30, and needs to be modded to be portable.if these chinkscopes can go anywhere near VHF, i'd say buy it
>>2864793> digital screen capture that would go for under $50scopes having their own screens for the last 20 years is one of the biggest scams ever.you could just as well use laptops, PCs, playstations, iphones and ipads, or even digital picture frames.… just ridiculous.
Personally I prefer giant hulking scopes with CRT displays on them.
>>2864818>biggest scams evertrue, buying anything is a scamwhen i need a scope, i order a Rigol, use it for a week, then return it to amazonbut the synth guy could probably get away with using a sound-card scope(BTW, i wouldnt buy a synth either, when a pirate version of Logic Pro comes with dozens included)
>>2864816>but $80 for 100MHz is a damn stealYes, if you just need one channel, and don't need an external trigger input. For what it is, it has good specs. But I'd rather have a 20MHz scope with two channels, all else being equal.>>2864818>>2864823I agree with the sentiment, but I think the software interface is kinda shitty. Much better to just adjust knobs.
>>2862970what sort of tesla coils designs have you done and how much RF noise did it generate? is it a narrow band based on the resonant frequency or is their some broad interference?
>>2864837idk bro i just found the image on an image search for "drsstc", i have never made a tesla coil before except for a slayer exciter kitif it really is properly resonant, you'll most prominently get that fundamental resonant peak, but i bet you'd still have a substantial amount of square harmonics unless you're doing proper zvs or zcs
https://github.com/74HC14/power-negotiation
>>2864708https://en.wikipedia.org/wiki/Chua%27s_circuithttps://en.wikipedia.org/wiki/Lorenz_system#Analysishttps://en.wikipedia.org/wiki/Negative_resistance#Oscillators
>>2864837i have not, but spark gaps are usually broadband as fuck. best bet is to get a RTL-SDR and a random wire antenna, then monitor the entire waterfall
>>2864886I kinda want to make a Chua diode, but is there any reason to besides having a random number generator? Is there anything neat I could plot with it on my scope in XY mode?
>>2864881Hmm, I'm realising that Multi-Master I2C is a lot better than UART, if I can isolate and extend it to comfortably run multiple metres.Does anyone have recommendations for I2C extension? Especially if they're also isolating, or at the very least can have a 50V offset between the ground on either side of the IC. Also I'd want them to run off 3.3V, but maybe that's silly, 5V is probably doable by changing my schematic a bit.
>>2864901 You can get white noise from a regular zener operated at it’s knee voltage.
>>2864909Look into RS422. Industrial standard.
>>2864828> software interface is kinda shittyI have a crt tek scope, and i completely agree—for long term use—sw scopes have shit interfaces.Short term, you could tolerate.BUT you could attach a scope control panel with the nice tactile dials, buttons, lights, to another USB port. For that, even USB 1.1 or bluetooth would be fine.Just like you could buy those joysticks that were shaped like steering wheels, pedals, and shifters for grand turismo on your praystation for car bros.
>>2864901https://youtu.be/rtR63-ecUNo?list=PLz-ePwn2hOw87QOrpFxTFOYvvOAe9-00p
https://www.codrey.com/electronic-circuits/white-noise-generator-an-analog-way/
>>2864939Osci-render and OsciStudio are neat. I wonder what can be done with an ultrasonic array interference pattern in 3D space with physical objects & gases.
I'm considering the new ifixit soldering iron, I'm at a point in my hobby where quality of life is one of my main priorities.Problem is I've become very dependent on this angled or bent tip and I don't think I'd survive without it.Am I alone in this preference or does anybody else main this tip?Would you expect the ifixit team to release this tip further down the line?
>>2865007> ifixitIt’s a soldering iron for field work.I’ve got a couple of butane irons for that kind of thing…Like when you go on site, crawl inside the mainframe, and the only power available is the huge 3-phase power plug, and you’d rather not clip across the power terminals (or, if they turned it off) Or, when you’re under the raised floor re-wiring a 25-pin D connector.I think i’ve got some bent tips around… never used them before. Standard chisel tip for 99.9% of everything. Once, I did some soldering with a lighter, a nail and a pair of pliers (nail gets hot). It went fine, but don’t put the nail point in the flame—it builds up soot and you can’t tin it.
I'm pretty retarded so hopefully someone can help meThe battery for my impact driver is dead and it's been discontinued so i can't get a new charger at the store.I have an agilent bench power supply i got for freeCan i charge the battery with this without blowing anything up?
>>2865069> charge with my ultra-expensive agilent bench supplyYou don’t say what models or anything, but generally older NiCd packs can be re-charged manually. Newer models have DRM and shit in their chargers and batterpacks.If it’s an 18 V pack, you might want to set the bench supply to, like 19 or 20 V and set the output current limit to 100 mA to test trickle charge it and see if that works.If it does, as you build confidence, checking if it gets too hot, etc, you could increase the current somewhat. But, it’s easier on the battery if you don’t quick-charge it.
>>2865074Its an agilent e3610a that only outputs up to 15 volts dc apparently so it won't work on my 18v lithium pack unfortunatelyAs stated initially I'm retarded, guess I'll have to buy a chinese knockoff charger
>>2865077What's the model of your impact driver?
>>2864934I need a multi-master multi-slave bus with collision avoidance and arbitration, and I need it to be isolatable with 5 wires or less. Isolating two differential pairs optically would require six wires, four for data and two for power. If there's a single pair protocol that acts as a bus I'm all ears, and I'd tentatively accept a two pair bus protocol that can be isolated with transformers. I'm trying to keep the BOM cost down and make it usable by common low-cost MCUs, so probably no CAN, but I'll consider it if there are cheap CAN transceivers that handle multi-master collision detection and arbitration.If I2C is good to 1m at 100kHz due to the capacitance of its wiring, would it naturally be good to 100m at 1kHz? I'd use properly shielded cable. Or is the high bus capacitance potentially damaging for the FETs when they pull the bus low?>>2865007>the new ifixit soldering ironIt's 5 times the price of a Pinecil, with only a few quality of life differences. Why?
>I2C multi-master multi-slave over 100m wiringDude, just use ethernet or something.
>>2865078Harbor freight earthquake xt lolApparently there is a charger in stock at a store an hour away, can't order them online anymore it says in store only Just got a 15 minute post timer, pretty crazy.
>>2865081In practice I'd only ever use it in 1-5m lengths, maybe up to 10m if I'm doing something real strange. I'm looking into CAN more seriously now. There are ICs like the MCP2515 that can allow any MCU with SPI to talk CAN and handle all the arbitration and retransmission of signals, but I'd still need a seperate bus transceiver and isolator. MCUs like the AT90CAN series might be cheaper and easier though.Gotta figure out where to buy the wire from too. Local shops don't have shielded twisted pair, but they do have shielded 4-core microphone cable, I wonder how much the twisted pairs matter if it's already shielded?
>>2865080> needs and wantsRS485 then. The other standard.>>2865096You can do ethernet over cat 1 no problem.Cat 1 is telephone wire, btw.Cheap, plentiful, and everywhere.>>2865081> dude, …This guy is probably right.Apparently, even an esp has a fake ether phy you can solder onto
What's the difference between all these multi-testers? Which one should I get?
>>2865096>AT90CANTurns out they're a lot more expensive than using CAN controller transceiver ICs like the TCAN4550. Though I'm not sure what I'd use for the isolated side, I'd want to use another TCAN4550 but the only isolators I can find are also transceivers, so I think I need a standalone controller instead. If only Microchip's website wasn't ass to navigate.>>2865111Ah, I didn't know RS485 was multipoint. I'll look into that too.>ethernet over cat 1I was under the impression that CAT1-4 referred to the number of twisted pairs present in the wire, so CAT1 would only have two conductors and so be unable to send an RX and TX signal at once like ethernet defines. Telephone connectors are often 4P2C or 6P2C or 2-pin BT, after all. But I could be wrong. I also don't know if anything implies it being twisted, since I've definitely seen 8P8C terminated flat ribbon ethernet cables before.I can locally buy 4-wire and 6-wire flat ribbon telephone cable, in addition to 4-core shielded cable for microphone use, but if these protocols call for two twisted pairs I'm hesitant to use them.Ethernet itself isn't a suitable protocol for me, it needs to be a multipoint bus. Requiring active switching components in any splitter is a pain.
>>2865118I bought an LCR-TC1, the UI looked the same as the TC-T7-H. I can't imagine there being an appreciable difference between the three, except the top one having a backlit LCD instead of an OLED. Still haven't figured out anything useful to do with the K and A pins on the ZIF socket. They're handy, but won't measure really small capacitors or inductors, and they struggle with inductors with too high an ESR. Not that accurate for inductors either. They're definitely useful, but no substitute for measuring inductance via scope for critical uses.
>>2865135Excellent points anon. I think TC1 can do thyristors etc that others can't.But yeah, these days everything is SMD and you can't test that shit easily. Not sure what the solution is.
>>2865134> Ethernet itself isn't a suitable protocolAhh, you probably want something like token ring then.
>>2865111>>2865134Looking into RS485, it lacks the collision avoidance and arbitration of CAN and I2C. While it's possible to detect collisions, preventing them seems difficult considering I2C and CAN controllers do it automatically. I'll be potentially having multiple identical masters and slaves, after all.>>2865182While I wouldn't use a standard abandoned 20 years ago, a ring topology is an interesting idea. Like a two-directional version of what WS2812s use. If I had connectors with switches in them like 3.5mm jacks, it would be quite possible to make such a protocol hot-pluggable with passive splitters. I won't be using such connectors, but it still isn't out of the question to use a ring topology instead of a bus topology. A UART ring would be very easy to implement, with each node simply retransmitting any message not addressed for it. It might be possible to use a single JFET between comms lines in a splitter, and turn it off when a new load is connected.I'll likely still use CAN though. Not only is it a robust protocol with all the features I need, its controllers, isolators, and transceivers aren't particularly expensive (though it would be nice to have some of that built into the MCU), and it's something I'd like to get some experience with for 3D printers and other projects.
>>2865077>only outputs up to 15 volts dc apparently so it won't work on my 18v lithium pack you can use a fixed voltage charger in series, and still enjoy adjustable voltage and current limitinga 12V@2A supply from a router, for example, extends your range from 0-15V to 12-27Vif only extending your penis was that easy
what kind of diode has the highest voltage drop without having an insane forward voltage? I want to drop voltage to slow the speed of a high amp low volt dc motor (30a run 70a start @12v) without using resistors or pwm or generally anything fancy pants, so a diode chain seems right up my alley, however I also don't want to have to chain like 9 diodes to get my desired drop.
>>2865268zener? or better yet, a shunt like a TL431.
>>2865282What does a 100 amp TL431 look like?
>>2865282don't zeners have a similar drop to regular diodes
>>2865268>highest voltage drop without having an insane forward voltageAren't those the same thing? Either way, 30A through a conventional 0.7V diode is going to dissipate 21W of power, you'd need heat-sinks for that.If you're trying to linearly regulate the speed of a motor, there's no way around heat production. If the motor acts like a 0.17Ω resistor on startup, then you can calculate for yourself how much power a linear element would dissipate if it were dropping a certain voltage.There are two sensible soft-start methods:>a big power resistor and a relay that bypasses it (a big NTC thermistor might be feasible too)>PWMI'd do the latter. There's probably motor driver ICs that monitor current for regulation, with which you can use to control a MOSFET on a DC motor.Or just run it on a lower voltage supply in the first place.
>>2862970I'm having trouble looking for a part; are there any listings of potentiometers that will fit with a rotating wheel? I struggled to find any that fit that description, and what I bought wound up being something weird where the center pin had a higher resistance to one side than the two side pins had to each other.
>>2865422Describe this better please, an image would be ideal. What's the difference between a wheel and a wide flat knob stuck to a normal pot?FYI don't use trimpots without first checking their cycle life, it's like 100 turns of use.
>>2862970Is Electronics for Dummies (like me) a passable book? Seems to be co-authored by some people from the recommended books section.>Books:>https://libgen.rs/No workie :'(
>>2865458libgen.is is currently working, same for libgen.st
I replaced a potentiometer on my controller, and now it seems permanently off centre and to the right, regardless of which white plastic wiper(?) I useCould I have damaged something, or did I simply use a bad part?
>>2865461>use a bad part?could be, obviously you need the replacement to hold the same number of kilo-ohmsif some kilo-ohms leaked out, you gotta top it off with a syringeanother possibility is you soldered it badlyor you damaged traces, or pads, or vias during desoldering or soldering
would it be possible to use a depletion-mode n-channel fet (maybe a jfet) as a high-side pass transistor to make a highly stable low-dropout linear regulator? The regulation of a JFET seems pretty good in spice with just a zener, if you used a TL431 (ideally a lower-current equivalent) you'd be able to make it even better. Though the gate current I'm seeing is a tad concerning, at least it still works with a gate diode.My intention is to make a 3.3V linear regulator that can regulate voltages both down to 5V and above 60V. All the 100V regulators have really high dropouts. An enhancement-mode MOSFET with guaranteed less than 1.7V dropout would work too, I guess.
Anyone recognize whatever the hell this is?Weird white crystal structures that turn into a powder when touched. Found on the chassis of an FM tuner, exclusively near the line outputs.I'm guessing corrosion of some kind but I've never heard of anything like this before. It's on the internal shielding on the RCA outputs, and on the parts of the chassis directly near it. None on the PCB itself.
>>2865468The part I replaced it with is new, but it's cheap and Chinese so could be bad. It's not like all the way to the right, but enough to register as a permanent right input. Say like 1/8th off. Ate the any easy way to check those, and if so, are they things I can fix?
>>2865432Sorry about the bad description, I was a bit tired when I posted that.The original pot (as far as I found with both testing it and looking up "D50K") was 50K Ohms. I'm trying to replace it because my attempts to get rid of the "dirty" "scratching noise" it was causing weren't effective while it was still in board. However, in case finding the correct replacement part proves to be too much of a pain in the ass, I'm considering prying up the plastic disc and trying to spray contact cleaner into the pot now that it's been desoldered. As for the replacement pots, pins one and three test 50K to each other, but pin two reads 50K as its minimum value, and 100K as its maximum. I've never encountered a pot like that before, and from what I've been told IRL, it's meant for Fade/Balance and Left/Right adjustment in audio systems.
>>2865515It's a dual-gang pot wired so that when you turn it, one terminal increases in resistance while the other decreases. Turn the pot all the way to the left and measure the resistance between terminals, then turn it all the way to the right and measure, then center.
>>2865522Not sure if I'm somehow measuring it wrong, I'm misremembering what I got last night, or I somehow have a defective batch (since I'm getting near identical readings from different pots), but twisting the knob on the pot doesn't seem to be affecting the values. From pin one to two, I'm getting ~100K; one to three, ~50K; and two to three, ~50K. I'm getting the same numbers regardless of knob position, and I'm wondering what the hell I'm doing wrong here, if anything.
>>2865593What you’re doing sounds right.Pins 1 & 2 should vary between 0 and 50KPins 2 & 3 should vary between 0 and 50KPins 1 & 3 should be fixed at 50KThat’s pretty standard.Also, they can be used for balance, but it’s just easier to make them that way, it’s very common to just use pins 1 and 2 as variable resistor for, say, volume control.
>>2865475I’m guessing that’s zinc oxide (or some other oxide of whatever they plated the metal with, e.g. tin)the same stuff they put into some sun tan lotions, diaper rash cream, and some paints.
>>2865601I'm just wondering why twisting the knob isn't changing the resistance values. Decided to try and get readings again, and I'm still getting 100k between one and two, and 50K between one and three and two and three. What's the probability that I got bad pots with the wiper disconnected from the knob, and stuck on one side of the pot?
>>2865616Adding onto this: There was also some "cream" colored junk on and near the original pot before I attempted to clean it. I removed it with some 90% IPA. Not sure how much it'd affect things, but I figured I should mention it.
>>2865616>>2865626Well fug me. I found my problem: I double checked the documentation, and for some ungodly reason, "pin" 2 is the two rear pins. Man, connecting this thing to the board correctly is going to be a nightmare.
>decide to build a 2 gain headphone power audio amplifier circuit on a perfboard (TPA6111A2)>design it all according to the best practices described in datasheets design procedure, with carefully picked component values>high pitched noise can be heard on output, even when powered from very clean 3.3V or 5V lineevery fucking time, i hate analog circuits so much it's unreal, it's all black magic
>>2862970So, my mom fried a dewalt 20v 10ah battery by leaving it in the mower all winter, I tried to jump it with another pack to bring the voltage up enough that the charger will recognize it, but it's not taking it. Just running a wire from B+ to B+ and B- to B-. Short of cracking the thing open and manually charging each cell with a power supply, is there anything else I can try? I'm not really an electronics guy.
>>2865639>lithium batteriesPlaying with these is a good way to have a battery fire. If they won't accept a charge, you're best off replacing the entire pack. Mixing new cells with questionable ones has a bad habit of leading to trouble.
Silicon controlled switch; SCR with an additional pin for turning the damn thing off
>>2865636 Just add a few filtering caps here and there maybe it'll help
>>2865639Sounds like a recent pack. Older packs didn’t have much (if anything) in them, but newer ones have special needs.For example, the ryobi 18 V one + lithium pack apparently needs +5 V on the middle pin before the pack will “allow” it to be charged.Unless the charge conditions are documented, or reverse engineered, you’re probably gonna have trouble.> 10 AhThat’s friggin’ huge!
>>2865639>Short of cracking the thing open and manually charging each cell with a power supply, is there anything else I can try?this is the only logical next stepunless you have a bench supply capable of going well over 20V while being able to limit current>>2865636>even when powered from very clean 3.3V or 5V line$100 says you're using a switching power supply which BY DEFINITION is not clean in any wayit's dirtier than your momand can't be cleaned up using filters caps or chokes coz the high-frequency noise hops/skips/jumps over any filteringwith audio, use ONLY linear supplies, batteries, or solar panels balance on your head>>2865655>SCR with an additional pinpart number or it didnt happen
>>2865684>high-frequency noise hops/skips/jumps over any filteringHigh-frequency noise is the easiest thing to filter out of a DC line, what are you even on about?. It's low frequency and the low-frequency components of white noise that's hard to attenuate passively.Even a simple LC filter should work here, as long as you go a bit heavy on the component values. Failing that, you can always combine it with the simple active filter that is a linear regulator.
>>2865636What power supply did you use? If it’s switching, don’t trust it without a zener-capacitor-transistor regulator afterwards. Monolithic linear regulators are shit at attenuating SMPS noise.It could also be oscillation in your amp chip, see if a small cap between output and inverting input helps.Post schematic.>>2865639Hook it up to a 19-24V power supply with a series resistor (e.g. 100-1000Ω power resistor) if not a current limited supply to see if any current is going into it. Those batteries can have perma-fail circuits that burn a fuse (and set software bits) when voltage goes below a certain level. Check out Tool Scientist’s teardown.
>>2865705>High-frequency noise is the easiest thing to filter out of a DC linecaps and coils cant stop noise when it's travelling thru the airit's like using a road block to stop jets
>>2865515i hope that alarm clock's alert tone can be set to the guitar riff from "bad to the bone">>2865722there's also common-mode interference
>>2865736It'd be a funny modification project, kek. But unfortunately, I don't think it'd be as effective at waking me up as the current tone.
https://www.youtube.com/watch?v=Fy2_CUBz40Athe madmen did itthey've printed a circuitboard
>>2865684>>2865712thanks, you're right, it's a switching power supply.I've connected the circuit to 3.6V Li-ion battery, and the noise is all gone, so it must be all been power related.I wonder what kind of magic filtering retail audio equipment is doing. For example, USB sound cards (like the apple USB - 3.5mm dongle) are powered entirely from USBs 5V line (which is noisy as fuck), and somehow they produce clean noise-free sound.
>>2865684NTE239
>>2865775They likely use chips with a far higher power-supply ripple rejection, they might also use a series choke. If the noise is way above audio frequencies (especially if it's spread-spectrum) it won't be very audible either.Your chip has 70dB PSRR, while an audio op-amp like the OPA2134 has over 100dB PSRR.For radiated interference, minimising loop area helps against magnetic noise, while grounded shielding helps against electric noise. Common-mode probably isn't an issue.
does anyone know if you can make an oled display transparent by disassembling it like an lcd? there is a 1.5 inch one out there, but I would like something 4-5 inches.
>>2863570okay i think this is my final thought. i'm trying to make my own """lo z""" adapter for my DMM, for measuring """ghost voltages""" and also quickly discharging capacitors.>fast blow fuse (1KV, 315mA)>3.3k fixed resistance (5W, 7KV pulse rated)>2 x 1.1k PTCs (1KV continuous rating)i think this looks reasonable given what i've seen in DMM tear-down videos but i'm not quite sure how to calculate this. absolute worst case would be the dead cold PTCs + fixed resistance equaling 5.5k cold resistance @ 1KV input = 181W dissipation... but this should be rapidly clamped. and i have a fuse to save my ass.
>https://www.youtube.com/watch?v=Fy2_CUBz40A>project binky: episode 39>prints solder traces onto a bare fr4 boardWhat is stopping someone from taking a soldering iron, putting on a small reservoir as a solder pot like>https://www.youtube.com/watch?v=9epxc6zpAh4and then getting some kind of valve to pour out solder like a solder pen.Although I'm not sure what mini valve would work with the high temperatures needed for molten solder. >>2865776It's in the special devices section of the book along with things like the PUT from the make electronics book.>https://www.allaboutcircuits.com/textbook/semiconductors/chpt-7/silicon-controlled-switch-scs/It's also all over the internet, if you just search silicon controlled switch. The all about circuits example shows a motor, but the book says it's max power output is around 275mW so you won't be running much.
>>2865836That solder pot's WAY too small to be useful. Also, the application it's used for in that video can readily be done with a normal soldering iron as long as the wires aren't too big.t. someone who's used an actual solder pot
>>2865678Yeah, the thing's only about a year old. Some scumbag saleman sold her on a meme mower, when she had a perfectly good gas mower with electric start, and despite me warning her not to keep the batteries in the goddamn thing when she's not using it, she did, and now she's out a $200 battery. I was hoping to save the battery because she's too stupid to learn from an expensive mistake and I figure I'm probably gonna be doing this again next year.
Is there a specific way to put a board/PCB into the metal helping hands or can you do it any way?Is it possible you can damage a board by placing it in the helping hands by scratching it or something? I'm worried I have
i'm making a double sided pcb with a MCU, DC regulators, and sensors on the top side and a 1W LoRa modem on the bottom side. space is really limited, so i have the DC-DC switching supply and MCU, along with power traces and SPI lines right on top of the modem i know the datasheet for the LoRa modem advises against this because it can fuck with the receiving side of the RF chip, so what are some possible ways to reduce interference and get the best range possible?
>>2865890>damage a board by placing it in the helping hands generally, PCBs can be scratched, drilled, sawed, filed, sanded, wire-brushed, lasered, tasered, dropped from airplanes into molten solder, acid, or lava; burned by torchesand still surviveany traces that were damaged can easily be repaired or replaced by wirethe only thing that can totally destroy a PCB is a noob with his helping handsbut that's easily avoided by wrapping 2 layers of masking tape over each jawor using inch-long pieces of heat shrink or aquarium tubing
>>2865950I am that noob anon. Other than tape what's a safe way of using the helping hands? It just felt odd clamping down hard on the board, and then when I went to use a solder sucker and shook the whole thing I think it was about the worst thing I could have done. Does this look like a broken trace to you?
>>2865953>Does this look like a broken trace to you?no, you just knocked off some solder mask (green paint) on the ground planethat's totally a non-issuethe lil trace next to it seems only mildly scuffed, not broken
Hey, looking for a hot-air station that won't burn down my house with chinesium components. Looked at the following recommended by plebbit, is this a fake or real version, and will it burn my house down?https://www.aliexpress.com/item/1005006856624471.htmlAny recommendations as well? Preferably as cheap as possible without burning the house down, if it has a soldering iron it's a bonus, needs to be good quality, I don't want blown transformers or fuses or DOA.
>>2865961i have the 957dw+, works fine. https://www.tequipment.net/Quick/957DW+/Desoldering-Equipment/Rework-Stations/
>>2865939Do a 4 layer board instead, to allow an unbroken ground plane between the SMPS and LoRa module. They’re only mildly more expensive from JLC. If you’re etching or routing the board yourself, then you can laminate two pieces of 2-sided FR-4 with unclad board in between. 4-sided vias are done the same way as for 2-sided boards, but you may need to indent your holes a bit to give the electroless silver plating a bit more room to bite between the layers.
>>2865950> picrelkek.. wtf is that supposed to be?
does anyone know what kind of sensor these devices use and that are available to buy? I would like to make my own version with an esp32https://mopeka.com/product/mopeka-pro-check-universal-steel-tanks/
>>2866026>non-pressurizedThese types of gauges/sensors work based off of temperature differential between the tank and surrounding environment.
>>2866032>These types of gauges/sensors work based off of temperature differential between the tank and surrounding environment.There's no way that's how that works. Beyond the fact that you can't do that for propane (the ones that work via thermochromic ink can only work on the side), the listing clearly states that it also works for things that don't cool themselves as the tank is emptied. "Diesel, Oil, Water, Propane, Butane, Anhydrous and other liquid commodities".My guess? It's some kind of ultrasonic sensor. It either compares resonant frequencies (which will change at varying levels of fullness) or possibly time-of-flight of a pulse reflecting off the surface of the liquid inside....which, looking up the manual for the thing, means I'm gay for even bothering to speculate. It is, indeed, a sonar sensor.https://mopeka.com/wp-content/uploads/2024/07/mopeka-procheck-universal.pdfIn any event, the hardware for this is dead simple. I strongly suspect the software side, however, is, uh...non-trivial.
>>2866035Time of flight ultrasonic is commonplace for tank level sensors. You can just buy a dedicated time-to-digital converter IC for that.
>>2866039>Time of flight ultrasonic is commonplace for tank level sensorsYes, but, to my knowledge, that's for sensors that sit in the top airspace of a tank. That's a much more well-defined reflection than going through the tank wall itself. I have no idea if there are any ready-to-go solutions for that one.
>>2866013i'm already doing 4 layers, with a dedicated ground plane closer to the RF module side. all the other layers have signals running across them but i could still copper fill them and do some ground stitching. not sure if that'll do anything though
>>2866046I think it would definitely be feasible to just couple the transducer to the top surface of the tank, like an ultrasonic cleaner does. Presumably the time-of-flight of any resonant modes travelling through the walls of the tank will be far shorter than the distances through air/gas in the top of the tank, but you could further dampen that by coupling the other side of the transducer to a ring around the transducer's centre.
does ESR depend on capacitance? if all the capacitors are ceramic, do i really need to use multiple decades in parallel?
Can i somehow measure ripple of the power supply without a scope?This stubborn piece of shit has strange faults with different symptoms ranging from hearable audio noise of drum and mechanism motors or fading video noise on power-on to voltage constantly rising very slowly on some of the power rails (just enough to set the level meter controller's mute pin to high and knock the arrows out). Even after replacing all of the faulty shit in the power supply it seems to still have problems.Strangely enough, when the mainboard is disconnected from the power supply, one of the power rails keeps its voltage and decreases it gradually instead of discharging immediately.
Idk anything about electronics. Trying to bypass the auto-off 3 hour timer on a heated blanket. Apparently this red CBB YC might control the timer. If I run a wire where I circled in the picture, will the blanket always stay on?
>>2866057>does ESR depend on capacitanceIndirectly it does, especially with spiral-wound caps with only one starting point. With SMD ceramics, less so, but there may still be a significant difference between 100pF and 100nF. But there are also differences in parasitic inductance, and in the dielectric material itself. For MLCCs, the inductance is far more significant than the ESR, which only comes into play exactly at the self-resonance frequency. I checked out a Samsung MLCC datasheet but didn't see a specific information about any size of capacitor, besides examples.I'd just follow the datasheet unless you have a good reason not to add extra caps.>>2866062Simplest method is to put your DMM in AC mode and measure the AC voltage across the DC output, with a good meter you can also get a reading of its frequency.
>>2866075>unless you have a good reason not to add extra caps.is laziness a good reason?
>>2866069>400V 670nF>two diodes feeding a zener diode>nearby power resistorNo, that's almost certainly a capacitive dropper cap, bypassing it will fry your electronics. I'd guess that it's probably not possible to bypass the timer function, as that 16-pin chip in the middle is going to be doing the timing inside itself. Bypassing the TRIAC so it's always on will also bypass the circuit that turns the blanket off when the NTC thermistor detects an overtemperature condition, which is a really fucking bad idea.There's only two options I can see:First, you could try to see if any of the little ceramic caps like C5 or C7 are part of an RC oscillator that feeds the IC's clock. Using a larger capacitor could then cause the timer to run a lot slower, maybe 9 hours would be fine for you. But it's still possible that the overtemperature circuit relies on a certain clock speed, say if it uses a capacitive ramp ADC. On the other hand, it may just use an asynchronous comparator for overtemp shut-off, in which case you could stop the main chip's clock oscillator entirely. Depends entirely on what that chip really is. Doesn't look like you can garner a part name off that blank face though, and I wouldn't attempt to bugger with the circuit without a datasheet, or maybe an oscilloscope to find a convincing relaxation oscillator signal. And it may just have an internal RC oscillator, like most cheap microcontrollers have these days, no cap to bugger with. Try reverse engineering the schematic if you're keen, I guess.The other option is to replace that PCB with something else, like an STC1000 or PID controller or maybe the board from a different electric blanket.I wouldn't advise doing any of that though, electric blankets are deathtraps without fucking around with their circuitry. Just buy a better (i.e. simpler) electric blanket. Not some branded wifi enabled bullshit that analyses your wet dreams.
>>2866069>bypass the auto-off 3 hour timer on a heated blanketlast week noticed they were selling Noma timers at the dollar storeif you use one to cut off power for 1 min every 2h57m, that should reset the 3-hour timeout
>>2866069Please remember that it's also a safety feature, don't holocaust a loved one, anon.
>>2866069>>2866079Oh, option 3 is to make a circuit to retrigger it once it turns off. You could probably use a single relay with a mains-voltage coil that "presses" the turn-on button when it loses power. Though the relay would run kinda hot all the time, there's also a small chance it would prevent the overtemperature protection from working.>>2866091Depends on his blanket, but I suspect it would start latched-off when it's powered on.
>>2865960Thanks, that saves some worry
dumb question, but what can I use to keep these connections in place once they're made? They keep snapping off as I insert/re-insert the battery. I don't have any electrical putty, I have electrical tape and that's it
>>2866069Ohh buddy you really shouldn't be playing with house current.
Appreciate the replies. I have decided it would be unwise of me to fuck around with the electric blanket. Originally, I had uploaded that photo to AI and asked it what I should do. Picrel was its response, which is why I assumed removing CBB YC might be the move. Glad I asked here and didn't just do it. >>2866079Thank you>>2866103It's for the cats :-)
Hey /diy/, first time posting here. I wanna keep my cat inside but don't wanna keep my whole house locked 24/7. Is there a way I could modify one of those to activate as the cat goes near sensors in the doors and windows? If this already exists I don't there there are options in the market in my country.Don't have any electronics diy experience but any help is welcome :)
>>2866164Forgot pic
>>2866164Does your cat know how to use doorknobs? I'm confused by the situation.
>>2866159Use a plant heating mat or waterbed heater with a weighted blanket on top. Insulate it from the floor with a rubber mat or sheet of OSB cut to size.
>>2866166I don't wanna keep all the doors and windows closed I live in a tropical climate dude
>>2866170Have you got/considered screens? Both window screens and screen doors are standard where I live.You can get pet proof ones, and it's possible to install them in a way they can be easily opened/removed (though most people here just leave them in all the time).
>>2866129Epoxy, hot-glue, neutral-cure silicone, UV-cure adhesive, so long as it's gap-filling, sets, and sticks to the board.>>2866159AI simply does not have the ability to reverse engineer a circuit board. Removing or shorting a cap out would have vastly different results in any situation, evidently there's just not enough training data out there. Or at least, whatever training data does exist isn't properly arranged in order to relate the responses to any images.
>>2866221shit I don't have any of those to hand. thanks for the response though
>>2866129>They keep snapping offkeep any glues off the PCB so you can make measurements and repairsinstead, use small drop of super-glue to attach each wire to plastic case at circled areasa rubber band can clamp each wire down until glue driesacetone can undo super-glue if needed
I'm trying to measure the capacitance of single capacitors and a bank of capacitors using a multimeter but no matter what I do it always reads 0 uf.Im using a milwaukee 2216-20 multimeter set to capacitance mode.I'm trying to measure individual electrolytic capacitors rated for 25V and 3300 uF, and a bank of 10 of the same capacitors connected in parallel.Things I've checked/tried:Ensured capacitors are fully discharged before testingThe capacitors are brand new and I have tested them to make sure they charge and are not totally DOA.I've double checked to make sure I am using the correct multimeter setting and the probes are in the correct holes.I've tried switching the polarity of the capacitor terminals (connect + lead to both + and - terminal on capacitor)What am I doing wrong here?
>>2866260post a picture
>>2866260>I'm trying to measure>a bank of 10 of the same capacitors connected in parallelLift the anode lead (+) of each cap to disconnect them from the circuit and try again.
>>2866265>>2866260Here you go>>2866266They are all soldered together. But even when I measure the individual capacitors that are not connected to any others I still get 0 uF.
>>2866267lol thats not zero, its overload
>>2866255Great idea. Thanks very much. You think I could just use electrical tape instead of glue or it wouldn't hold?This isn't a part I plan to constantly readjust, but my controller has been acting up and so I've been having to constantly test and retest, meaning yanking the battery constantly and because it sits loose without the holder, on occasion the wires rip off. Also you reckon I should bend back or cover the plastic I broken into or will it be fine?
>>28662673000uF is out of range for that meter.
>>2866260Manual says it can only measure up to 1000 uF
>>2866269>>2866272fucking hell I'm a moron. God damn I'm stupid. Jesus chirst how did I miss this.
>>2866277happens to the best of us fren <3
>>2866277>I made a mistake so I must sudokuAre you Asian, Anon? I don't mean brown poo Asian, but squinty yellow Asian.
>>2866280>Are you Asian, Anon?nope, very white I tried testing them a week ago and couldnt figure out what was wrong, and also looked again today, just surprised I mistook OL for 0 I guess>>2866278lol it really does.On a semi-related note, here is the bank of 10 already soldered together. The plan is to add up to 10 more to this, and I'm trying to decide what the best way to do that is. I think I can solder on the extras upside down above the existing ones, mirroring it vertically. The other option is to make another little bank and connect it to this existing one. Another thing to consider is that I also plan to eventually add a separate charge port/connector of some kind and maybe even 3d print a little enclosure for it too.Its a cheap spot welder for putting together battery packs from individual cells.
>>2866159>removing the capacitor may cause the circuit to behave unpredictably>shorting it will notwhat
>>2866312Removing it makes a break in the wire, shorting it turns it into a wire. But the AI has missed something here. Changing *anything* will result in unpredictable behavior if you don't analyze what the circuit does/think about what will happen, so by definition both options would make it behave "unpredictably"
>>2866322>But the AI has missed something hereThe AI answered confidently
>>2866271>use electrical tapesure but electrical tape sticks best to itselfso you have to wrap it all around the battery a couple of times, which may make for a tight fit>should bend back or cover the plastic I broken anything that's sticking up gets chopped off like Bruce Jenner's stick shift
Free lab: Ohm's law demonstration.
go back >>>/gif/
>>2866312There is actually some sense to it, now that I think harder. If it was considering it to be a timing capacitor (such as with a 555 timer), shorting it out would just leave the timer in a fixed state. But desoldering a timing capacitor would just leave stray capacitance and propagation delay, causing the oscillator to run much faster. If there’s any circuit an AI might have enough training data to intuit with regards to, it would be a 555 circuit.But in this case, it’s obvious the AI didn’t train on a thousand hours of Big Clive footage.Anyone else wanna collaborate on a project to train a neural network to convert schematic images into netlists?
Okay I'm retarded but I want to somehow convert several devices that are powered by 9v batteries to being plugged into an american wall outlet. I know how to solder the wires but not much else. Is this feasible?
>>2866364>Is this feasible?impossible to sayi searched all the literature and no one's tried it before
>>2866364>buy 9V wall adapters>buy chassis-mount DC jacks>solder up with correct plug polarity>profitBeware that for audio uses, common switched-mode supplies can be damn noisy.
Can anyone advise me on strange PC motherboard working? >Want to read the PLED pin with microcontroller>5v when power on, 0v when off.>Microcontroller is PULL DOWN and IN>Whether the PC is ON or OFF the PLED always outputs 5v when the microcontroller is connected.Why might this be? When google and my trusty new friend Claude can't help - I come to you retards.
>>2866364Yes, it's feasible. You can replace the 9V battery snap on connector with a barrel jack and power it with a 9V wall wart, or a USB-C trigger board instead of a barrel jack, and power it with a USB-C PSU.
>>2866394Measure the PLED- pin instead, it should go from 5V when off to 0V when on, as I think it gets turned on by a low-side transistor.
>>2866448im confused, dont I need to connect + to a gpio pin and - to ground?
>>2866456It's a power output going to LEDs, it's going to be switched on and off with a MOSFET. Low-side N-channel MOSFETs have better specs than high-side P-channel MOSFETs, so you basically only ever see N-channels. Pic related, consider the R_load's two ends to be either sides of your connector. You'll need to use some other 0V reference.
>>2866479Interesting. I have ground from the USB 2.0 header. Ill give a try tomorrow thanks
I'm looking for a chip consisting of a crystal oscillator driver and a PLL for frequency multiplication. I feel like there's got to be plenty of models available but google and digikey search aren't helping. Digikey does a really bad job indicating if their PLL chips can have a crystal connected directly to them. Anybody know the name of a chip like I'm describing?
>>2866497I had a look under the name "DDS", but I still just found chips with a single pin clock input. Probably because TCXOs and their ovenised variants are objectively better than bare crystals. If you really want to just use a crystal by itself, chuck it across a CMOS inverter I guess.
What kind of LED panel should I buy to cheap out on photography/videography lighting? I'm not paying NEEWER $150 for an rgb panel with a diffuser and tripod.If I'm not concerned with color cast, etc, can I just get a grow light on amazon for $20 (the led panel type) and then jb weld it to a shitty tripod?Just looked on amazon and the panels are less $20 and more $40I fucking hate this planet
>>2866159>people ask AI for advice>people actually put their house on fire because they think the randomly generated words have meaningEvolution at work. Really fucking shame you still asked some humans.
>>2866332Thank you
>>2866525Its 2024 grandpa get with the times, the stuff ai can do is amazing and its the worst itll ever be
>>2866578Get fried by your own stupidity, boomer.
>>2866583im not sure you know what boomer means, grandpa.
>>2866586Boomers are the main group of people who fully believe in AI.
I asked this before but I think it got lost in the noise.Im making a spot welder for tacking together battery packs and want to add 10 more capacitors to this, should I solder them on by vertically mirroring the bottom and have the new capacitors coming out of the top upside down, or should I make another little module and connect that to the existing one somehow?Im thinking having them on the top would be better. I wouldnt have to add any more wiring that way and there wouldnt be any chance of current limiting the connection between the two, but I'm afraid it would look stupid and/or cover up the cool looking top of the existing one.Fucking hell I've typed like 8 captchas to post this
>>2866678this isnt really a question about electronics
I want to make my own (analog) guitar pedals, I'm an electronics engineer grad student so I know (sort of) how to manipulate a signal in the way I want it to be, but I don't know precisely what guitar pedals really do (like an overdrive/wah/chorus/fuzz...) to the signal - I mean, I can kind of guess it or reverse engineer it from existing schematics, but I was looking for a comprehensive source that tells you "This effect usually achieves this sound with a transfer function that looks sort of like this" or whatever
>>2866678bus bars
>the device says i2c address is 0x78 on back>it doesn't work>scan all addresses, it is 0x3cam I missing something or are these chinks trolling me
>>2866694With vs. without LSB which is used for I forgot what.
>>2866700PS: I think saying 0x78 is more correct, while 0x3C would be used by someone who only uses I2C libraries.
>>2866694>>28667000x78 = 011110000x3C = 00111100hmmm i wonder what it could be...
>>2866700oh sorry i thought you were OP
>>2866700>>2866701>>2866703so it is about bit order and people have disagreements on how address should be represented?
>>2866706honestly my first thought was that you were fucking up the transmission somehow.
>>2866706>bit orderIt's not the order. The LSB is the R/W bit. It's a question of convention whether the address should include the lower bit (0x78), or only the 7 upper bits (0x3C). You could argue for either.
>>2866708I am using hardware i2c on pico.
>>2866686>"This effect usually achieves this sound with a transfer function that looks sort of like this" or whateverLOLGuitar shit is for meatbrains, forget you ever learned the term "transfer function" and start gluing shit together.Roughly speaking, fuzz/overdrive/distortion are all the same (diode/tranny saturation), and chorus/delay/echo/reverb/flanger are all variants of delay (look up the Haas effect - there's a fundamental difference between sub-25ms and >25ms delays), often with an op-amp based triangle wave LFO build in. If you really want to delve into complex nerd shit, look up how a crybaby wah pedal works. Genuine masterpiece in analog design, and requires a bit of electromechanical knowhow to pull off. Octave doublers and halvers are also pretty cool.
>>2866694Also speaking of these SH1107 displays, they all seem to have their own flavor of how memory is mapped to display. Different type/resolution of displays often requires different addresses or other constants
>>2866678Technically, shorter wires are better. Especially for very short high-current pulses. In practice though I’m not sure how much of an impact it will make.>>2866686All I can recommend is the YouTube channels Moritz Klein and Lantertronics. Sound-au.com might have some stuff too. Moritz just did a video on BBD ICs, which are used to make delay, chorus, phaser, and flanger effects IIRC.Generally there are a few main categories of guitar effect:>harmonic distortion by clipping or similar such as fuzz, overdrive, octave>VCA-based, like a tremolo, sustain, or compressor>filter-based, like a wah>delay-based, like the chorus and such I referred to aboveI’m probably forgetting something.There’s also a lot to learn from the modular synth world, with VCAs, VCOs, VCFs, side-chains, using the envelope of a signal for feedback, that sort of thing.I want to make an e-bow.
I don't have any experience with battery monitoring. As far as I can tell these two have the same specs, except one has a slightly nicer display. Is there any other reason to get the more expensive one?https://www.altronics.com.au/p/q0591-flush-mount-power-monitor-panel-with-100a-shunt/https://www.altronics.com.au/p/q0594-flush-mount-50a-coulometer-with-shunt/The use case is I have a 12V battery that I want to power a little camping fridge. I'd like to monitor the battery so I know how long it will power the fridge for.
>>2866764The main reason to get the more expensive one is it presumably converts the battery voltage into a percent value, assuming a certain chemistry. But if you don't mind remembering what voltage means what (or printing off a chart) then it doesn't really matter. When it's being charged the voltage goes up to 14V or more anyhow, so either way you won't get a good reading.The cheaper meter measures watt-hours, while the more expensive one measures amp-hours, which are a bit more accurate for estimating remaining capacity, but you'll likely have to reset them to 100% after each charge cycle. I've tested the cheaper one with positive AND negative currents (i.e. having all current going to and from the battery going through the shunt) but it only integrated the outgoing current into its Wh reading. At that point you might as well just get a voltage meter, as the Wh reading really isn't that useful unless you also have a way of monitoring the input power (e.g. display on your solar charge controller). And Ah would be better either way, since voltage drop in the cable reduces the perceived Wh reading.If the more expensive one from your links does bidirectional current, then you can probably rely on its Ah value going up and down to stay accurate, but I've no experience with this model. I assume they realise when they're being overcharged and just clamp the maximum capacity to 100%.Picrel does bidirectional current, I have tested the Powertech branded version of it, it's 500A maximum and 8-80VDC.t. works retail in a place that sells these in AU/NZ
Are there any power muxes with 8 channels?
>>2866913Probably not. Just use MOSFETs and a bit of digital logic, maybe also comparators. Why would you want such a thing in the first place? Why not just use diodes?
How is it that the ISO1050 has a ±58V bus fault tolerance, but can only handle ±12V common mode range? What do these terms actually mean?
>>2866913> Power mux with 8 channels.You do like this
>variable supply voltage of 5V or more>want to use isolated CAN transceiver IC that needs a 5V rail (4.5-5.5V)>use linear regulator with under 150mV dropout set to 4.7VI see no problem with this whatsoever.>>2867021Ah I see, the common mode range is the range within which messages must still be intelligible, while the fault tolerance range is the range in which it can physically survive. If I want to extend it beyond this I suspect TVS diodes alone won't be enough, they'll blow up if exposed to a continuous short. Maybe I can put a series polyfuse on each data line before the TVS diodes?
