Old thread is no longer bumpin' >>3002473>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.>Comprehensive list of electronics resources:https://github.com/kitspace/awesome-electronics>Project ideas:https://hackaday.iohttps://instructables.com/tag/type-id/category-technology/https://adafruit.comhttps://makezine.com/category/electronics/>Books:https://libgen.is/>Principles (by increasing skill level):Mims III, Getting Started in ElectronicsGeier, How to Diagnose & Fix Everything ElectronicKybett & Boysen, All New Electronics Self-Teaching GuideScherz & Monk, Practical Electronics for InventorsHorowitz and Hill, The Art of Electronics>Recommended software tools:KiCAD 6+CircuitmakerLogisim Evolution>Recommended Components/equipment:OctopartLCSCeBay/AliExpress sellers, for component assortments/sample kits (caveat emptor)Local independent electronics distributorsladyada.net/library/procure/hobbyist.html>Most relevant YouTube channels:EEVblogW2AEWMoritz Klein>microcontroller specific problems?>>>/diy/mcg>I have junk, what do?Can it run Doom?>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?>>>/x/
>>3007000Literal page 2 bake? That’s barely half the thread’s full lifetime. It’s a general, not like front page bumping matters at all. Waiting until page 8-10 is how it’s been done for at least a few years.
>>3007000I'm looking for a new Multimeter and I can't decide between the Amazon Commercial 90DM619 and the Kaiweets HT118E.I've also taken a look at the UNI-T UT139C, but that's not available right now.Any meters that I'm missing? Budget is 50€ tops.
>>300847790DM610*Missing my Numpad right now.
>>3007000>>3008491>Diodes pointing towards FB means you get the greater of the two feedback signals, diodes pointing away from FB (wth a pull-up resistors) means you get the lesser of the two feedbacks signals.i see this now (in ltspice.) thanks for saving me a frustratingly stupid board revision.>Even the small amount of ripple that gets through your low-pass filter will be hugely amplified by your error amplifiers, resulting in a bunch of output ripple.are PWM DACs more difficult than i'm perceiving? settling time doesn't really matter to me. 100 khz PWM through a 30K and 100nF RC filter should yield roughly 1.65 mv ripple peak to peak on a 3.3V input. that's close to 11 bits? afaik DACs don't have output ripple but shouldn't this ripple be functionally the same as the precision/accuracy of a 10-11 bit DAC?>Seems like Q1A is a bit superfluousQ1A exists to shut off the charging power path no matter what happens. i selected them to withstand VCC (20V from USB-C.) normal charge termination? shut off charging. buck converter fails and the output rail sees 20V? shut off charging.>If it’s tied to ground in a single-supply circuit, it will clip any negative voltagesi don't want to charge a dead battery since it's unsafe. off-board comparators check for a minimum voltage, like 3.0V for an 18650. a reverse polarity cell would read 0V, as would an absent cell. a dead cell would read <3V. comparators trigger SD LATCH, no current flow can occur because Q1A/Q1B are held off.
>>3008496typo:Q1B exists to shut off the charging power path no matter what happens. i selected them to withstand VCC (20V from USB-C.) normal charge termination? shut off charging. buck converter fails and the output rail sees 20V? shut off charging.Q1A exists to shut off the discharging power path in the case of the IRFP250N blowing up.
>>3008497> IRFP250NWhy not use bipolar, they’re more robust and usually handle around 60 V
>>3008498>Why not use bipolar, they’re more robust and usually handle around 60 Vi have a dozen IRFP250N on hand. i've used them in pic related to 100W and 10A sustained. they should be more than adequate for 10-20W (heat sink limited).
>>3008496>that's close to 11 bitsYeah but the R2R DAC isn’t oscillating by half an LSB thousands of times per second. If your error amplifier gain is like 0dB at the PWM frequency it’s probably not an issue, but I’d definitely calculate that.Q1A won’t shut off charging, only discharging. If your buck converter outputs 20V, you’ll have to catch that in software and shut off Q1B.I guess worst case with that voltage sense amplifier is it starts clipping the signal, so you detect a 0V battery or a backwards battery as the same. But I’d still want to be able to tell the difference between those, and avoid any issues with the amplifier not behaving well close to its negative output rail. I’d want to be able to measure down 2.5V at least, for LFPs and DW01-protected cells.
>>3008501I’m looking at the datasheet, you’ll be in the thermal instability range at anywhere below 45A in the VCCS operating mode. So I’d be cautious.
How does an op-amp work?
>>3008550> how opamp workIt’s like a super-good transistor.The “op” is that you can configure it to do summing, difference, integration, inverting, etc etc ad nauseam with a bit of extra circuitry.The “amp” is that it amplifies with configurable gain.
>>3008550Long-tailed pair (possibly with darlingtons) as an initial differential amplifier, plus a few additional (I think common-emitter) gain stages, followed by a push-pull output stage. The long-tailed pair has a very high effective input impedance, and the push-pull stage has a very low effective output impedance. With all that gain in the middle, any nonlinearities and parasitic behaviour flattens out when you use negative feedback.
This is what I am being taught in college.It's flat out 2 amps and I have calculated the math all other resistors. Am I retarded?
>>3008582Here is another one, one typo means the problem is wrong, even spaces count the problem as wrong and it does not ask for the math. I did it in fractions, not decimals.
>>3008582I don't know why but my screenshots are always sideways when they are vertical in ny gallery. Anyways, I ain't ask for homework, these are already counted against me.
>>3007000Can I run 24v through a 12v KDC4 switch. 12v isnt giving my motors the torque I want and the electronics housing is designed for the kdc4. Now Im reading that kdc4 switches are designed for AC and not really meant to handle more than 12v but im confused because some switches say up to 36v (despite have a 12v label).
>>3008587>>3008583>>3008582It is because you are posting from a phone. Phones assume all their users are retarded, when only most of their users are retarded. Post from a PC. You know, like the one you are taking the picture of? You can screenshot whatever you want using Windows Key + Shift + S. If that is too hard, and you use Google Photos, you can access your phones on the web by going to photos.google.com. You can then download them and use an image viewer like IrfanView to make sure they are rotated properly before posting them here.If you are on an iPhone, well, just ignore everything I just said and deal with the fact that your pictures are sometimes rotated.
>>3008613Usually you can, but it will have it’s current derated.DC has an sustained arcing problem, that’s why the DC current rating is so ridiculously low. There’s probably a formula for it based off the AC rating, but it’s likely non-linear and they can’t print every DC voltage/current rating on it.
>>3008619Is there any way I can figure out the dc/current rating. I realized I forgot to include the current. The switch I have is rated for 12v 40a or 250vac 30a. Im trying to run 24v 8~10a max.
>>3008615Fair
>>3008628At absolute worst it will be 50% of the 12V rating, it’s probably closer to 75%. So 10A will be fine if it’s rated for 40A at 12V. One technique is to find comparable rocker switches on places like DigiKey that give you more thorough datasheets.
>>3008615I actually did try doing a screenshot but the screenshot takes up too much space to be used on 4chan.
>>3008641How to prove you are a Zoomer without outright saying you are a Zoomer.You can change the file format of the image. Use JPG instead of PNG. It takes up much less space. Also, don't take a full screen capture. Use 'snipping area' to only capture the part of the screen you need.
>>3008636Thanks. I was afraid I was going to have change to a different switch model and have to design the housing from scratch.
They don't seem to make pcb-mountable SSRs at the current rating I need (5-6A) plus they're kinda pricey anyway. So I'm thinking of implementing it myself.Is it just an opto and a triac? Just wire the micro into a zero-crossing opto then wire that up to the triac?Do I need to care about zero-crossing on the micro, maybe to align the control signal it emits?
>>3008692If they were to implement SSRs today, they’d probably use two mosfets back-to-back in opposite directions to handle the AC.I don’t think you have to worry about zero crossing that much in this application unless the noise spike is causing problems.Why solid state? Lots of things still use regular relays for switching heating elements (stoves, toaster ovens). Some even manage to attempt to control the relay at the z/c like mr carlson did on his refrigerator to increase the lifespan of the little pcb relay… in addition to the snubber network.
>>3008693>they’d probably use two mosfets back-to-back in opposite directions to handle the ACI've seen this in diagrams too, any advantages to this approach?>I don’t think you have to worry about zero crossing that much in this applicationSpace is pretty tight so I was hoping it'd reduce heat somewhat not having to switch at the peak. I may be misunderstanding this though.>Why solid state?Fast switching to vary power to a heating element since it's heating a very small mass and has to stick closely to a temperature.(Specifically it's for a coffee machine)
>>3008666I wish I was a zoomer lol, grew up without a phone. But good tip.
>>3008696What's growing up with a phone got to do with anything? When I was a kid, phones came in two types: Rotary and Touch-Tone. When smartphones came out I hated them. I only got one because a new job I got in 2014 required one. I still hate them. Laptops and tablets too. 104 keys, a full sized mouse, and at least two big screens is the only way to do it. Gotta have a sound system too. Headphones are junk.>I wish I was a zoomer lolAre you saying you are were born before Windows 95 released yet don't know how to use a computer? Fuck dude, what have you been doing? Not getting ripped and fucking chicks, that's for sure. You are on 4chan.
>>3008692If you want easy-mode, buy a digitally controlled dimmerlink board from rbdimmer.com. Cheaper than aliexpress. You don’t need to care about zero crossing synchronisation, there’s a little MCU that handles that for you, just speak UART or I2C to it and say what dimming percent to set. They make both monolithic boards with a triac and optotriac, and controller boards that have just the MCU on it. That said, my reading suggests they don’t do pulse skipping, only phase-angle control. So good for loads that need high speed, bad for situations where EMI matters.A conventional circuit with zero-crossing is definitely doable yourself, just make sure you’ve got enough timers and interrupt time for it. Maybe the RP2040’s PIO system can handle it for you without interrupting the CPU. If you want to do phase angle control, I believe optotriacs with built-in zero-crossing circuits won’t work, they wait until zero crossing before turning on the output. Just learnt this today.If speed REALLY doesn’t matter, as in lots of full AC cycles between turning on and off, then forget the zero crossing and just switch it on and off open-loop. A zero-crossing optotriac will make for low-transient switching operations.But if you want something faster, especially PID control, then pulse skipping, if not full phase-angle, with a zero-crossing detection circuit is the way to go. They’re pretty easy, just an optocoupler and some diodes and resistors and stuff. It’s basically an established design. The code is the harder part for me.>>3008693I’ve also seen people put a bridge rectifier in series with the AC load and put a single MOSFET in there. Easier to drive, but in both cases they need isolated driving circuits that are more difficult than an optotriac. At least you can just arbitrarily PWM the MOSFETs without caring about zero crossing, but whether you should is another matter. Seems like a recipe for even more EMI than phase-angle control.
>>3008697Based cellphone hater. I’m waiting for an open source hardware dumbphone that’s actually good. Calls, texts, maps, ideally an end-to-end encrypted messaging platform, and maybe an authenticator for 2-factor things. Headphone jack. Can act as a 4G router for your cyberdeck. A week of battery life because it doesn’t do anything in the background, besides polling for messages and calls. Let people write custom executables for it in Fortran.>headphonesYou should take the chifi IEM pill. When the cables break, you replace just the cables. I recommend the Truthear Gate, though lately I got the Salnotes Zero 2 and it’s been great.
How do I make my own drill battery charger if the one that came with my drill craps out? Does it have those microcontroller thingies that would detect you're using a counterfeit one? It's 20V and I just wanna hook it up to a regular 20V power supply
>>3008700Sorry bro, they ain't gonna hold a candle to my 5 speaker surround sound system with full range speakers. When I upgrade my rig, once the AI bubble pops, I'm going to get a sound card that can handle 7 speaker surround. I already have the speakers for it. Earbuds are even worse than headphones. Their tinny little dogshit drivers cannot handle proper sound output. Especially when trying to reproduce wildly different frequencies simultaneously. Headphones are super bad about it and earbuds are worse.At least they don't put a dent in your head. Picture related.
>>3008707Get a CC/CV DC-DC converter module. Probably a buck converter module like an LM2596 (the one with two or three trimpots), run it off a 24V supply. Set to probably 21.0V and some sensible amount of current (less than the converter’s maximum, and less than your 24V adapter’s maximum too), verify the settings with your multimeter. Wire the output up to one of those tool battery adapters. I think you can typically just feed power into its pins without any communication, though I’d probably seek a second opinion from an authority on your battery brand in particular.>>3008709I like having channel separation and no destructive interference between channels in the event my head is 5mm off the centre of the room. Proper IEMs often use multiple types of drivers to cover a wider range of frequencies. Because the required SPL at the driver is so low, the drivers end up being significantly underdriven, with plenty of headroom. If the frequency response is still a bit off, EQ can cover for that so long as you’re not running into distortion. Also I only have two ears, and the vast majority of music is only mixed in stereo anyhow.Now I’d you’re arguing that the phase relationship isn’t accounted for by standard EQs, you’re right. But:>human ears can’t really hear phase offsets in a note, though this isn’t an absolute I suspect there are cases where it might be noticeable>a digital EQ could be designed to compensate phase too, it’s quite possible that such a thing already exists>the phase relationship between multiple speakers that are spatially separated is even more significant and harder to control
>>3008697This was my first phone, so you're gate keeping a person who is already further down the path than you.Anyways, I had the instructor run through the math, this is an electrical engineer, only to figure out that 6/3 is 2.
>>3008700The vacuum tubes are EMP resistant for when the government electrocutes your balls
>>3008724I spend most of my time on video games and movies/TV, so much of it does have surround sound mixes. I'm in a computer chair connected to a mouse and keyboard so I don't have a problem with moving out of the sweet spot. Plus, my amplifiers allow for multiple speaker configurations. If I wanted to, I could just get another set of speakers, mount them in an idea position for music listening only, and then turn a knob on the amp powering the front channels to have them power the 'music' speakers.As for EQs, I listen to so many different genres of music from so many different eras that programming an EQ to be able to handle every album would be a nightmare. Everything from Anamanaguchi to the ZZ Top. Brian Bennett to Chuck Berry. Motörhead to Matthieu Chedid. Then add all the different games, movies, and TV shows I watch? Nah. I'd rather have a system that just sounds good no matter what I'm doing. Plus I like to feel it in my chest when shit blows up. You can't do that with earbuds and you don't even have to have the volume up that high to do it with full sized multi-driver speakers.
>>3008768No you just EQ to make the speakers or IEMs sound neutral (e.g. harman target, or perfectly flat), then listen to the audio as intended by the album. The audio chain between the .mp3 bits and the sound pressure should be transparent, it shouldn’t colour the sound one way or the other. Swapping between EQs each time you listen to a different genre is absurd. If the mix is so bad you have to EQ it differently to make it sound good, then bake a modified frequency response into your .wav so it sounds like god intended without having to fiddle with your EQ settings.
I found a 2tb external hard drive with 30% health. Is it still possible to repair it?
>>3008795Are the platters ok? Are the heads safely parked? The spindle motor/bearing?
>>3008699>rbdimmer.comLooks like cuckflare cucked them out of potential visits. Is "dimmerlink" a generic name or their own product?
>>3008666>Be GenX>Be completely forgottenAlso first half of GenZ is millennial-Lite and better with computers than actual millennials (I use Debian btw).t. 28 y/o comp-sci Zoomer
>>3008819I think it’s their trademark. I haven’t seen an equivalent from any other brand, except for arguably the Kemo M150.Also I’m pretty sure you could replace the variable resistor in a normal analogue dimmer circuit with an LDR and blast it with an LED controlled by a microcontroller, the only issue being its maximum voltage rating. Maybe you could put a few LDRs in series and balance them with TVS diodes in parallel with each. Otherwise, looks like wider diameter photocells have higher voltage ratings, with the 20mm ones being capable of 500V.
>>3008695> mosfets, any advantages to this approach?Modern mosfets (hexfets) have insanely low “on” resistance and need less heatsinking which can be a major space saver.>>3008699> a bridge rectifier in series with the AC load and put a single MOSFET in thereThat’s brilliant, especially if you have some spare bridge rectifiers around… same power, just pulsed DC.
>>3008824Ah, but the first half of Millennials (and the back half of Gen-X) are Xenials!>Xennials are described as having had an analog childhood and a digital young adulthoodWe are a post-computer generation but a pre-internet generation. Early Gen-Xers were already preteenagers/teens when computers started entering the home but many later ones, and early Millennials, grew up with early these computers. Remember, many of those home machines booted up to a BASIC interpreter or had one built in. That started you off in a very different mindset then starting from a GUI. Even business machines, like the IBM and its clones, generally booted to a command line (DOS). Plus all the best games ran in DOS.You had to know how to use a computer to install games. It was a completely different experience to what came later. Check this shit out:https://youtu.be/V-t-zTkNka8?t=90https://www.tiktok.com/@geekjam/video/7397922669213076779https://youtu.be/cioyLQ2O6ycWhen you put a disk/disc into your PC it didn't do shit in DOS. You have to know what the drive letter was, how to list the contents of the directory, start the installer, configure your own sound & graphics settings, maybe even fuck around with extended memory, and then know how to navigate to where you installed the thing. Only then could you play. Lord fucking save you if you needed to setup a boot disk (fuck you Ultima VII).Then came Windows and Direct X and installers became this:https://www.youtube.com/watch?v=TCymoV8jVkwPop in the CD, it would autorun (this guy had to do it manually because modern PCs turn that shit off), chose install, and hit next a bunch. Done. If you were born too late you simply had no idea.Even old consoles didn't hold you hand. No cartridge? Here's a flashing screen. Figure it out, dumbass. Better have it tuned the correct channel and have the switches set correctly. Some of you have no idea what I'm talking about.The PlayStation gave you this:https://youtu.be/r_Ifccgl05A
>>3008824>>3008867Xenials are the technology Precursors. Elder Gods. I've used a rotary phone. I have watched a film... on film using a projector that I operated. I have swapped reel to reel tapes (for music and data). I have programmed a VCR. I have tuned a TV. Not changed a channel, *tuned* each channel button using switches and dials like a DJ. Picture related. No one can do that anymore. Analog TV is dead. I've been on the roof of a house fucking with an antenna. I know why the save icon looks like that because I lived it.Before USB was a glint in Joe Decuir's eye I battled with parallel ports, serial ports, Centronics ports, PS/2 ports (fuck you IBM), and game ports. I used to keep a floppy disk with backup copies of all my computers drivers for when shit hit the fan. I've had to manually configure IRQ ports. Copyright protection used to mean looking up a line in the manual to type in or using a Dial-a-Pirate:https://youtu.be/7tMGNgofeyU Not connecting to the internet. Fancy programs used a thing called a 'dongle' to prevent piracy. No, I'm being serious. That is what it is called. Troubleshooting the office copier that has brought everyone to a standstill? That doesn't even work up a sweat. I can deploy that at the server level using a GPO, preconfigure and lock down the settings so no one can fuck it up, and even make sure the Mongos can see two entries when printing; one for black & white only and one for color, just to make it as simple as possible.Comparing early GenZ to an early Millennial is laughable. I remember when Linux wasn't even a thing. I remember when Windows Updates weren't even a thing either. Shit, we used to reinstall our operating systems once a year just to keep the performance up. I've been using emulators and virtual machines to run different OS's and systems on their non-native hardware longer than you have been alive. I went to a vintage gaming show and bought a T-shirt there back when you wert still in diapers.
>>3008873> Centronics portsUSB C connectors have 24 pins.We’re back baby, we’re back!
Needed to modify a w1099 temperature+humidity control module. By default its humidity regulation would vent all the hot air I’m building up and prevent it from getting up to temperature, so I had to ensure the humidity controlled load would only activate when the heater was off. Next, because this is a 12V module and I want to run it at 24V, I had to add a 12V regulator, linear because I don’t have any 24V capable miniature buck converters lying about. Then that was dissipating too much power, so I swapped the relays for MOSFETs. I was going to have to add an additional BJT to invert the signal going to the FET gate, until I realised the 5V MCU outputs were capable of driving a logic-level power FET (IRLZ44N) by themselves. So I desoldered the onboard BJTs and ran a jumper wire to the FET gates. Hopefully this setup should work more reliably than the original relay design, I’m only switching 2A@24V, but there’s going to be a bit of heat nearby.I might need to blob something in to mitigate vibration, but it feels pretty rigid.
I need some BNC to RCA adapters to use a PVM I picked up with more devices. Is stuff from Hosa (hosatech.com) worth a damn or is it just rebranded Chinese trash like everyone else's shit?
I've decided I want to spend more time learning the actual theory/math behind this shit. I have tinkered and got things to work on my breadboard, but I don't like having such a big knowledge gap. For people who know their shit (even on a smaller scale like just small circuit stuff), how did you best learn it?
>>3008956University courses that recorded on YT, edx and mit. And also free pdf uni textbooks from web. That's how I did it
>>3008956Once you get ohm’s law, KCL/KVL, complex impedences, and the common components (passives, transistors, op-amps), you should have enough of an intuition to get by self-taught. When you need to learn how to make a good feedback loop, you look into control theory. When you need to do some dac or adc work, you look into nyquist sampling theory. When you need to handle high frequencies over significant distances, you look into transmission lines. That’s how I did it, having learnt the basics from a university course.
>>3008975We can tell you haven't been to a university because of how you write.
>>3008956A lot of the app notes and circuit descriptions have a “theory of operation” section, so just stop ignoring those. That way, if you’re using a component or IC, you’ll have a reason to go in-depth on things that you don’t know that was mentioned in those app notes.
I would like to see that wonderful photo of an ATX power supply turned into a benchtop supply. Barrier terminal block on top of the housing with voltages written in Sharpie.Do any of you know what I'm talking about?Please share it. Also do me a huge favor and have a great day. Thank you.
>>3009285I have the pic, but my testicles are visible and I'll get banned with a rubber hammer by an unpaid intern if I post it. Just use your imagination.
Speaking of benchtop, I think a benchtop multimeter is preferable to a handheld. Especially if it has two independent inputs
>>3009297Benchtop makes sense if you already have two handheld meters, or need it to do kelvin 4-wire testing or to have more than 4-6 digits. So, less than 0.1% of multimeter owners. That said, I want to buy some of those symbol Nixie tubes (Ω, V, A, F, H, and m, μ, M, n, p, k) and make a benchtop meter for that.
I got a pretty good accuracy with my 0-500mA high side current sense circuit. Should certainly be accurate enough for my project (fan controller thingy). Schematic coming up.
>>3009344
>>3009345I don’t get the principle of operation. I see circuits like this inside op-amp internal schematics, what is that arrangement of transistors called?
Found an old router. What parts can I salvage from it? Would like the antennas but they're probably going to be too big for my laptop's wifi card.
>>3009448Turn it into a flash drive NAS that holds OS install media, drivers, and docs.or install Doom. Once you start salvaging components it will be useless, so make it do something useful.
Anybody got some good recommendations to study these topics?
>>3009349AFAIK it has two current mirrors which force the currents on both legs of the circuit to be equal. R3 adds a small offset to the output voltage so it would start at 75mV when the load current is 0mA.
>>3009538I'm familiar with the normal 2 transistor current-mirror, but the 4-transistor doesn't seem to be a trivial extension of that. Even then, all the 4-transistor current-mirrors I see people using have 4 NPNs, not 2 NPNs and 2 PNPs. It doesn't seem obvious how they'd be different, but that just makes me more curious why that choice was made.Also, how a current mirror makes for a good differential amplifier, especially one with a single-ended output relative to ground or 12V, isn't obvious to me either. I guess a long-tailed pair would be less linear, and maybe the current mirror is much better at being immune to common-mode noise? But I'd want to test what fluctuations in that 12V rail do to this circuit, seems to me that the current through both brances of the mirror is fundamentally dependant on that 12V rail, and so any voltage measured will be proportional to the 12V rail (e.g. Vout = k * V1 * I * (R1 + R2)).
>>3009504ETA-International study guide.
>magic smoke escapes the power tool>look inside>0.2uF 5 connector capacitor from west germanythey sure don't make em like they used towhat now?
>>3009640It's a dual capacitor meant to reduce arcing thus extending brush life, as well as noise filtration. You can still run the tool without the cap, but you should check and/or replace the brushes first.
>first time ever building something that uses a gyrator>it actually worksamazingfor those wondering it's for the supply side of a bias tee. I want to present >1 MOhm impedance to a 700 Hz signal coming back up the coax. the gyrator simulates a 1 kH inductorI had to add a diode to bring the overshoot under control during startup, but other than that it's been behaving excellentlynow to solder this up and put it in a nice 3D printed box
>>3009809>>3009810>>3009811Look at this butthole talkin shit.
>>3009793What sensor needs 1kH? Is the output signal really low frequency?
>>3009837I could bump the frequency up with the current choice of opamp. but I also need to spin a new design that uses a less power, because 50 mW is way too high. the most extreme is MAX40018 which only pulls 1.6 µA quiescent current per channel, but it has a pathetic gain-bandwidth product of 9 kHz. the AD8505 is more reasonable, but still only 95 kHz. and it uses a whopping 27.5 µA per channel
>>3009837oh and I designed the sensor myself if that isn't clear
>>3009844What kind of sensor is it? What aspect of reality does it measure? Temperature? Radiant intensity? I've only seen bias tees used in RX antennas.
What can I make with a solenoid water pump salvaged from an old steamer?
>>3009868not sure how much I can reveal at the moment. that said, here's the realization of the circuitI had issues with the output sagging seemingly at random which I traced to leakage into the 10 MOhm series network. letting the resistor hang in the air, and drilling out all copper around the high impedance node solved the issue. all my multimeters are too low impedance to actually measure there
If you guys were to recommend ONE book that everyone interested in electrical stuff should read, what would it be? I'm talking extreme basics: what is current, voltage, amps, etc. Essentially something like an electric for dummies handbook.
>>3009911Forrest Mims
>>3009907Spray that circuit with some conformal coating to prevent atmospheric dust and grime from causing leakage problems.
you wanna see what a motherfucker looks like?
>>3009953Oof, did that failure damage anything else? Overvoltage to a CPU or RAM?
>>3009960luckily no. i measured 8 ohms between atx 12v and gnd. i was scared it was going through silicon because it was low but not zero. so i removed the cpu and measured again: 8 ohms.measuring closer to ground zero was 2 ohms or less, measuring across the blown cap was dead short. basic cleaning with alcohol actually removed the short, but the smug jackass in me wanted to clean it properly, so i put flux and solder and wicked it back out. the fucking short came back.i added solder and wicked it out again and again till there was no solder left, but the short stayed. i was mad and disappointed,the pads were gone, the nearby resistor came out, the mosfet underneath was starting to feel the heat. i hated myself for wanting to do it right, and mostly didn't understand where the connection was happening. i knew it wasn't the mosfet but where else.
>>3009962i ended up digging under the surface and severing the two sides physically. which removed the short. i double checked components against a boardview to make sure they were happy, and put it back together. it worked thankfully.
>>3009940good idea. I even got some PCB laquer recently not that I expect dust to be a huge problem here since it's going in a box
What to do with a dead graphics card
>>3010076If the silicon is dead then it's trash, otherwise it's practice.
>>3010076Might be some intact high bandwidth memory on it? That shit’s worth more than gold these days.
>>3010076snip the edge connectors and sell them to a gold refiner. you'll probably want to collect at least 1 kg of them first
are you really supposed to just pray you don't bridge the pins when measuring a laptop charger ic? are there like, one sided probes available?
>>3010194yeah it's a risk. you gotta use test points, and finer probes. i burned an ic inside a tv because of clumsy measuring.
>>3010194What do you mean by measure? Where are you measuring?
>>3010194There are SMD probing stations with needle-like probes held in articulated mounts. Usually designed around a microscope, they look pretty expensive but maybe you can get some aliexpress probe holders to use alongside a PCB holder. You can also get micro gripper probes, they have little claws that extend like a pearl-clutch, and are small enough to grab a TSSOP pin without shorting to nearby pins. Without any fancy hardware, maybe you should try soldering tiny wires onto pads you want to measure. You can solder them on while it’s not powered, and inspect the joint closely for shorts before you risk turning the power on.
Do I need thicker wires for this one?
>>3010248It's 16W, so 68mA minimum. It might have a terrible power factor, but if your wire can handle 0.5A you should be fine. In other words, you could use wire as thin as 30awg and you'd probably be alright, though I'd probably use something like 24awg. More important would be finding wire that's got mains rated insulation, if that means 10A mains wire then so be it. Though I'd want to use either very rigid wire (well supported >1mm strands) or very flexible wire (<0.1mm strands) if there's any chance that the vibration of the pump could work harden and embrittle the wire. Fastening the wire down tightly with cable clamps and isolating the vibration of the pump as much as possible is what I'd attempt.
Looking for some great needle nose pliers for soldering, anyone? Shopping from Amazon only.
>>3010248power = voltage x currentso current = power / voltageso current = 16W / 220V = 0.072A meaning the thinnest wire you have rated for 220V is more than adequate
>>3010194>bridge the pins when measuring a laptop charger ic?if the cable is made using 2 wires side by side, then stick needles in the 2 wires and measurethe holes will close when you remove the needlesalternately, salvage a female connector from some old equipment
>>3010278I recommend a set of small stainless forceps. They clamp onto the part or wire so you don’t need to provide constant tension with your fingers while soldering fiddly parts, and they provide more clamping force than reverse springloaded tweezers. Otherwise, anything with a return spring, thin jaws, and grippy teeth, pic related.>>3010282Watch out for power factor!>>3010283He’s talking about the IC, the thing on a circuit board, probably on the laptop board not inside the charger. Presumably he’s measuring more than just the output voltage.
>>3010092> sell them to a gold refinerThose edge cards have an expected plug-in cycle life of approximately 1 time.For this reason, they’ve perfected getting the gold plating as close to 1 atom thick as possible. You’d need 10’s of thousands of these things to get a negligible amount of gold out of them. The cost of cyanuric acid alone far outweighs the amount of gold you you’d get.
>>3010352ok just give all connectors to me if you don't want 'em
i'm trying to turn an open collector comparator into a latching signal. when the comparator output goes low, the latch goes high. the latch can only be reset if the comparator output returns to high.this seems to work in falstad. as far as i can tell, "setup and hold" constraints don't exist for SR latches because they aren't clocked circuits? would the only edge case therefore be some sort of minimum pulse time for the circuit to latch?https://www.falstad.com/s.php?s=zTQ17G
Is there any benefit to desoldering smd components and IC chips
>>3010386after some more reading, apparently these do have setup and hold constraints. my "enable" signal (analogy to the clock in a D latch, i guess?) will always be pulled up, and so i am guaranteed to meet the setup and hold constraints. is that right?
>>3010387>any benefit to desoldering smd componentswhen society collapses, these will be used as the standard exchange currency for hookers and dope
>>3010391Them some funny lookin' chips ya got there, boi.
>>3010387Yeah, it’s the same benefit you get from desoldering thru hole components.Most commonly, you can get cool regulators, tvm diodes, polyfuses, current shunts… things like that. I make things like oscillators with discrete transistors, I got about 30 of them from an old sony TV… used 2 of them to make the speed control signal for a delta fan.
>>3010392it's gay-ai. the uncanny wall is proving to be impenetrable.
>>3010386So you want it to be manually reset, but only for this to be able to happen when the comparator isn’t still trying to set it? Yeah, an SR latch with a tiny bit of combinatorial logic on the input is the way to go. It doesn’t need to be a gated latch, that enable input is superfluous. Then you can DeMorgan your circuit to make a simpler one out of NOR gates.While flip-flop ICs already have edge triggered clock inputs, I can’t think of a situation where this would be overridden by the comparator signal. Maybe a JK flip-flop, with K tied high and J tied low, reset into CLK, and the comparator going into an asynchronous SET pin? I’d want to browse some datasheets to find one with asynchronous set/reset pins, and where the async set being high overrides the resetting clock input.I guess the same idea would apply to a D flip-flop with async set/reset, if you tie D low.>>3010387To replace dead chips, obviously.Sometimes a chip will have firmware programmed onto it, or it will be otherwise hard-paired to work with specific other serial numbered components, so you’ll have to desolder it from a bad PCB and transplant it on the replacement PCB.And some chips are just valuable enough to be worth the labour even for reselling.
Why use any of those convenient pre-made LCD adaptor boards when you can spend the time and money to make your own, using much bigger PDIP ICs?
I think it was last thread someone helped me with the layout of this awful Frankenstein board with its mix of THT and SMT components
>>3010314With serrated or smooth jaws?
>>3010490>serrated or smooth you need both for diff jobsserrated is a better choice 90% of the time, tho
>>3010497Different anon, what do you use smooth jaws for? I find their low gripping power basically makes them useless. If someone made pliers with grippy vulcanised rubber or hard silicone jaw covers though, that could be handy.
>>3010519>what do you use smooth jaws for?straightening things like wires, component leads, and chip pins without damaging themalso forming wires and sheet metal into shapes, again without scratchingadjusting links in jewellery chains; metal glass frames; grabbing tiny plastic lenses
>>3010520I don't see how it matters for component leads and chip pins. Insulated wires, especially with soft insulation, I can understand. Same for jewellery, glass, optics, etc.
>>3010521nta, but first thing that would comes to mind are gold plated pins for example. They are not gold plated for fun, nor for the great conductivity of gold, but because you don't want them to corrode.If you scratch those you could drastically reduce their life span. Also silver wire or magnet wire. The point is to being able to grab and bend stuff without scratching thin coatings for electrical reasons and not just for having a pretty surface finish.>just my 2 cents
>>3010524Ah I see where you’re coming from. If I was going to solder to them anyhow who cares, but if it’s part of a connector then yeah it would be valuable to preserve the coating. Though even then, the corners on some flat jawed pliers could bite into the coating, especially thin magnet wire. I’ll see if anyone has made rubber jawed pliers or forceps.
>>3010527>rubber jawed pliers or forcepsJust get some round-nose pliers.
Has anyone here gone through the process of lab testing a design for CE compliance? Do you have any advice?
Can I post here without being bullied? I've always like the idea of making little things with components. I've just no idea where or how to get started.It's mostly because I have a little device and the button stopped working. When I took it apart it the little button/switch inside had snapped from the solder. I bought a replacement switch, solder iron, all of that shit...and that was pretty much it. It's sort of like a tactile switch, but the more rectangular kind and it's absolutely tiny which just makes it more difficult for someone like me.Where do I start bros? What do I practice on first?
Pins 4 and 5 have no continuity on my VGA cable. I'd get a new one but I also want some learning experience. Where should I begin.
>>3010565> little device and the button stopped workingSecret Plot Device.
>>3010573Do you realize how rare it is to have a broken VGA cable?
>>3010573>Where should I beginfor a clean-looking result, you'd need like $50 in parts and toolsbut a used one at the thrift store is like $2for a learning experience, i'd suggest convincing your sister to experimentthey're the best teachers>>3010565>What do I practice on first?youtube videos"Basketball players who only visualized shooting improved their free-throw accuracy by 23%, nearly matching the 24% improvement of players who practiced physically" -- Alan Richardson, 1960
Any recommendations for an inline mains plug power meter? I want a compact one to chuck in my toolbox to help me troubleshoot electronics. Having no screen and a Bluetooth app instead would be fine, but I’m looking for one that accurately measures power factor on nonlinear/ switching loads. My current cheap one is measuring 80W from a 50W supply, and browsing about it’s hard to tell which ones are measuring phase offset for reactive loads, and which ones are actually continually multiplying the instantaneous voltage and current values and taking the rms of that.I’ve considered making my own, if it’s just measuring current then it’s pretty trivial to cram a current transformer inside a piggyback plug and run wires to my DMM. That would be useful for 99% of uses, so I’d consider making one of those for on the road, and having a nice Hopi meter or equivalent at home. Adding power-factor would require a microcontroller, I’d probably take a series resistor (plus TVS) from the mains input and run it into a little audio transformer to make a power supply and an isolated voltage measurement waveform. Maybe I could cram it all in the housing of a smart-plug. But the coding sounds like a pain.Any recommendations? AU plug btw.
>>3010565>snapped from the solder.If it was just a cold joint it's probably an easy fix.If the pad lifted it could be significantly more difficult.
>>3010573IIRC many VGA cables don't have all wires to begin with, if you haven't yet it would be good to make sure they're meant to be there before assuming it's broken
>>3008666I love how Gen X doesn't even exist at all. Either too tied up around work or collecting their Funko!Pops. Strange nobody even mentions them ever.
>>3007000are there any off the shelf solutions for low voltage ideal diodes? most ideal diode controllers use the bus voltage to power the IC, meaning it won't function with low voltage. i need it to function with a bus voltage as low as 0.7V.
I'm starting a community on making our own RAM. It doesn't matter if it's 512mb or 4gb. If my RAM sticks crap out I ain't shelling 100 bucks for 1 stick.
>>3010650i guess i mean to say, other than LTC4353 which is pure ass rape at $12 ea.
Don't know anything about electrical work but it looks like my first project is going to be replacing outlets. Got almost all the tools I need: screwdriver (obviously), voltage tester, pliers. About to go to Ace and buy a set of wire cutters. Anything in particular I should look for?
>>3010670The only tool you need is the screwdriver. You can test for voltage with any device that plugs into an outlet. A nightlight for example. Pliers are unneeded. Same with wire cutters.Replacing an outlet laterally consists of turning off the breakers, checking the outlet with a lamp, unscrewing the faceplate, unscrewing the outlet from the box, pulling the outlet out, unscrewing the screw terminals to remove the wires, putting the wires on the new outlet terminals, tightening the screw terminals, placing the outlet back in the box, screwing it to the box, placing the faceplate on it, and screwing it down.
>>3010670Get a square drive bit if your outlets will accept it (most do). Phillips sucks dick.>>3010706You mustn't have ever replaced backstabbed outlets. They get extremely hot under load and you end up having to cut off at least an inch of wire to get to clean copper and uncooked insulation when replacing them.
>>3010706Like I said, I'm new to all of this. I watched several videos, one of which suggested having wire cutters handy in case the wires were inserted into the back of the outlet and became a bitch to get out (like the anon below you said). I bought a pair of Klein cutters as I've had good experiences with that brand previously. Unfortunately it was all for naught. I get to the house, plug in the wire tester, then go to the breaker box in the basement. The panel is not labeled (for the most part). Some switches ARE, with things like "sump pump," "microwave," other appliances. So I start at the bottom, flip, go back upstairs, check. I repeated that process for every single unlabeled switch on the panel (30 or so), and none of them killed outlet I was testing. By then I was tired from going up and down the stairs a hundred times so I got fed up and left. Later this week I'll go back with my wife and skip the marathon.As for the actual replacement, I'm pretty confident I can do it. Every video I watched echoed your steps. Got the tools, got the replacement parts. In the meantime I'll just curse my FIL for not labeling the panel. It's funny because he was one of the most particular, organized people I've ever met. We're talking about a guy who saved everything. I was going through a desk in his office and found receipts for every single electronic/appliance/material/home good he ever purchased. Example: the Zenith 32" color TV set (with remote!) back in 1978. I found a notebook detailing all of the materials he bought to build the house. All this is to say that I'm surprised a guy like that didn't label his panel. Who knows. Maybe the paper slipped off or is in a drawer somewhere. >>3010711The way Phillips is designed had to be some guy fucking with us. The shape itself seems tailor made to make stripping the screw easier. What the fuck was he thinking?
>>3010711>Get a square drive bit if your outlets will accept itWhich won't help with the faceplate or stab in connectors. You can generally release stab ins with a flathead unless they are melted in. You could get a multibit driver or just a second screwdriver but, eh. Robersons are very nice otherwise. Their only real problem is their heads are ugly. So, not for finish work that people will see but great for everything else.>>3010713>The shape itself seems tailor made to make stripping the screw easier. What the fuck was he thinking?>>3010711>Phillips sucks dick.Agreed but there was a method to the madness. They were designed to be used in manufacturing with early powered drivers that had primitive clutches or no clutches at all. It was preferable for the head to cam out than either overdrive the screw into the material or have it snap at the shaft. Specifically, it would throw out the driver, which often cammed out the screw, instead of driving the screw further into the material and potentially causing bigger problems. This 'feature' of the Phillips was known at least as early as 1942. They caught on and became so entrenched that they still dominate even though better clutches and better head designs have been around for decades.
>>3010650At some point, you just gotta use a comparator or long tailed pair to switch the MOSFET. Have you tried looking at the energy harvesting field?>>3010651You’ll be lucky to get 64M. What’s the plan, those share-a-wafer custom silicon providers? I want someone to make Optane again, or just some form of high reliability (single level) flash storage.>>3010723The worst part of Phillips is probably not the camming out, but the presence of JIS and PoziDriv and one or two other too similar looking bit types that people get confused. Additionally, some narrow screws in plastic enclosures use PH2, but are down holes thinner than the standard 5-6mm PH2 shaft. Had to go out of my way to buy 4mm PH2 and 3mm PH1 bits from aliexpress, 150mm long.You’d ever have that problem with hex keys. Probably torx too, I think they’re usually not much wider shanks than the torx shape itself?
>>3010732I stripped a torx screw on a smart plug a while back because it was like a T6.5
>>3010670Turn off the breaker and follow the code where you live.
>>3010723>Their only real problem is their heads are ugly. So, not for finish work that people will see but great for everything else.I know it's a regional thing, but it's kind of funny to see this. Exposed robertson heads are everywhere where I live and nobody thinks twice about it. Though, faceplates are still often godawful flat for some reason.While torx is in theory stronger, from what I've seen, robertson generally does better in less optimal situations (which is usually the case). Either one is way better than phillips.
>>3010732>At some point, you just gotta use a comparator or long tailed pair to switch the MOSFET. Have you tried looking at the energy harvesting field?pretending for a second that i had a charge pump or floating supply to address the highs side NMOS drive requirements, would this stand a chance at working IRL?https://www.falstad.com/s.php?s=KN2O0ki think i would need a linear solution (op amps) rather than hysteretic. initially i thought TI LM74610 would have worked as an off-the-shelf solution then i read the details of its hysteretic operation: it won't clamp reverse current until V(drain,source) > 20 mV. this is several amps of current flow for a low RDS_on FET, with a potential indefinite reverse current flow if the 20 mV threshold is never crossed.
What do they mean when they used to build gadgets from off the shelf components?
>>3010765>high side NMOSAww, you can’t have low-side NMOS? And your current is high enough that PMOS isn’t an option? If your current is high, you’re probably best off using a dedicated gate driver with at least sn amp of source and sink current. You can probably find such a driver with a built-in charge pump, then control it from a comparator.You don’t want something linear, you want your FET either hard on or hard off. Anything in between and it dies to ohmic losses or spirito instability. And op-amps are slow when used in saturation, though with some diodes you can mostly avoid this. You want both speed and minimal hysteresis, I guess you should experiment for yourself what parts and assemblies might be suitable for this.
>>3010740> like a T6.5That should be illegal.Next they’ll “invent” T6.25 and T6.75I was already through with torx, the screws simply don’t stay on the driver bit when you have to put the screw in a recessed box, then I end up cutting my hand open trying to fish out dropped screws in the box already overfilled with live wires and splices.
>>3010723> phillips… preferable for the head to cam outThat is a myth. It was never designed to cam-out. It was designed to make it very easy to set the screw in the bit, and can be done in a factory when dealing with 1000s of screws. It’s self-setting. Any drywaller will tell you that, and it’s why they’re used for sheetrock (with clutches) because they don’t cam out without the clutch… especially on a new ph2 bit. But I can do 1 every second because I don’t have have to wiggle the bit back and forth to get the bit seated in the screwhead like all others.
Desoldering SMD components isn't worth it imho. Boomers were lucky they could get free components back then.
>>3010808It's possible it's Torx Plus, but it's not like it would be easy to tell at that size.
>>3010821> Torx PlusAnother torx standard? roflmao… i hope you’re pulling my leg here… that’s insane
>>3010818do you not have a heat gun?
>>3010834They introduce a new variation every time the patent expires. Gotta keep the royalties flowing somehow.
>>3010818It is worth it if the chips are worth saving. CPUs, RAM, and flash memory chips come to mind.>>3010834There’s also Torx Ttap. And it’s also similar looking to Polydrive.
>>3010850and the torxheads keep crying that the entire planet hasn't taken up the standard yet.i wonder why?
How do I turn this phone on without a battery? It vibrates when I hold the power button but there's no display.
>>3010856Idk man, what voltage are you feeding it? It looks like that resistor goes from V+ to V-, but usually the thermistors are a third pin to ground. If you have a real battery, you could measure the voltages on its pins and compare them to your spoofing setup.
How easy is it to fix a TV? Is it as simple as opening it up and seeing something with a burn mark on it that needs replaced?
>>3010959No. If the problem is something nonspecific, like it won't turn on, it can take hours for a skilled tech to figure out what is wrong.
>>3010959Very easy. I'm not even trained nor can read schematic
>>3010962Fuck sake. I think one of them might need the screen replaced because there's sound and no picture, but the other one just doesn't turn on.>>3010964Sounds dubious.
My next project is going to convert an old Samsung into a janky droid deck with a rudimentary controller or mini PC. Probably without a battery.
>>3010959opening the back without breaking the panel takes: 5-10 minutes. longer if the back is clipped on and have to be pried off.confirming power supply outputs correct voltages: 5-10 minutesdiagnosing why it's not outputting correct voltages: 5 minutes to never.confirming if the backlight is functioning by detaching motherboard: 2 minutes.confirming no short on main board by probing inductors: 1-2 minutesfixing a shorted power rail by removing or replacing component: 10-20 minutes .. zero minutes if you use a screwdriver to knock a shorted capconfirming correct voltage on all power rails: 5-35 minutes depending on how quickly you can trace lines and see the small text. fixing missing voltage by replacing mosfet, or ic: 10-30 minutesconfirming no shorts on t-con: 1-5 minutesreplacing component on t-con: 5:20 minuetsreplacing a COF chip: 30 minutes and about $15,000 for the tap bonding machinereplacing panel: 20 minutes if it's a matter of ordering a new one and wiring mainboard, psu and speakers ..etc to it
Just tried to solder a SoM onto a prototype PCB and shit doesn't work. Don't know if it's because I messed up the soldering or because the board itself is defective. Either way that's probably a few hundred dollars and weeks of time wasted to produce a new one.
>>3010791i found this from TI, using a nice yet affordable comparator that i wasn't familiar with (TLV1805.) https://www.ti.com/lit/an/snoaa23a/snoaa23a.pdfi think i'll try building the nmos version, although i still don't quite understand the point of the "anchoring" diode they use (DB2430100L), even after reading the description.>The output diode D4 is used to "anchor" the output during light or floating loads. At light or no loads (less than reverse current threshold), there is a possibility the MOSFET could turn on due to the comparator offset voltage. The diode provides enough of a negative leakage to turn the MOSFET off.
>>3011015Looks like a reasonable circuit. Ultimately there’s some amount of time and voltage slack in your circuit, the amount of current you’ll be seeing will determine whether the delay will cause that body diode to cook.What’s the application? Solar?
If I power a 12V brushed DC motor with 48V or even more, but with current limiting to within its design current, will anything go wrong? Maybe I’d need a fairly conservative current limit, or a constant power circuit, but it seems reasonable to expect it won’t die by overheating if this is done properly. The speed will slowly creep up, to a much higher top speed than possible at its design voltage. Does high speed damage the brushes? Would the higher voltage cause excessive arcing at the commutator? Is there a fluid you can submerge a brushed DC motor in to prevent arcing, I wonder?
>>3011036>What’s the application? Solar?battery charging
This logic chip can debounce 6 mechanical switch contacts
>>3011084So can a 74HC14 with some caps and resistors, but neat to know there are dedicated ICs out there.
>>3010670Following up on this. Got some time to go to the house and get into it. I got a whopping four outlets and one switch changed. Very small in the grand scheme of what needs done, but I'm feeling good about it, maybe even a bit proud. Never done anything like this before. One of them took me nearly an hour; what I THINK happened is the ground wire wasn't long enough when they initially wired everything, so they spliced another piece to it, which resulted in the box being extremely cramped. After I got it wired I was having a hell of a time making the outlet not be cocked to one side so I spent a stupid amount of time straightening it. In the end I was 95% happy with it (pic related). Like anon warned of here >>3010711, they used the "insert the wire into the back of the outlet instead of using the screws" method, and they were indeed stuck like hell. I clipped them as close as I could and re-stripped them, then screwed them down. This is pretty tedious work but it's actually been very gratifying being able to DIY something and having it be successful. This house has so many damn outlets. That room in my picture has nine alone, and it's only about 12' x 14'. Total for just the upstairs is probably 70-80 outlets. Will take a while but paying a professional I'm sure it'd cost me hundreds in just labor. After I finish this I will work on replacing the doorbell chime. Need to research that one a bit more first and figure out the transformer issue.
>>3010959First step is probably determining if it's a TV nice enough to bother repairing.>>3010975What's the reasoning behind blurring the photo?
>>3011135Forgot the picture.
1998 sony handycam shuts off when flipping the switch to camera mode to open the lenses. It still has current but the entire thing goes off and the lights on the playback buttons go black. When switching to playback mode the entire thing goes back to life.
>>3011140Also forgot to mention that it's hooked up to its own power adapter. Don't really have those specific sony alkaline batteries available.
>>3011140It’s probably drawing too many amps for one reason or another. Dodgy motor, or dodgy motor driver. Maybe it requires the battery to buffer its power because the adapter can’t source enough instantaneous current. For a similar reason, maybe capacitors that handle inrush have gone bad.Gonna take some nostalgic images with CCD artefacts?
Debounce THIS
>>3011159For what purpose does that existI know reed relays are used in signal switching, but that seems excessive
i'm trying to layout a current sense resistor and current sense op amp. pic related is the optimal solution, but my current flow is in the opposite direction. this means the left side of the resistor has to connect to (IN+), and the right side of the resistor has to connect to (IN-). i don't want do deal with two sided assembly. what's the preferred approach?>keep op amp positioned as the picture shows>route one shunt trace on top of board>route another shunt trace on bottom of board>use vias on both traces to match impedanceOR>rotate op amp 180 degrees>route shunt traces on top of board>route REF and OUT on the bottom layer with viasi don't need the utmost accuracy or anything, i'm just wondering if one option is materially better than the another. FWIW it will be a 4 layer board and the middle 2 layers are both ground pours.
>>3011194I don’t see why the sense input lines would need to be short, length-matched, or just on one side of the board. They’re low impedance signals after all. Current sense amps are only so fast (I’m surprised there aren’t low pass filters on the sense lines), and you need to have extremely fast signals for an extra few mm to matter. Vias to flip the input wires seems trivial and with no downside.That said, flipping the part and running more traces underneath it seems relatively elegant. Are you using REF, or just tying it to GND?
>>3011194Some INAs may have alternative pin orderings available. Maybe check that first >>3011189 Probably a switch matrix for some huge automated testing systems
