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Charles Ford posted:I suspect they weren't "recycled" (like they weren't pulled off a board or anything), but programmed at the Microsemi factory (as a service they offer), placed on the reel, then at some point they fell into the hands of PCBWay's suppliers. If you want to count just selling pre-owned, unused otherwise original parts as counterfeit then sure, of course. I feel like I'm in bizarro land, how are you not upset about being sold defective parts? Parts that are, at best some form of supply chain injection or (IMO more likely to be) some sort of ewaste counterfeit?
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Apr 26, 2024 21:04
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Are you surprised? Did they have a contract that specifies preferred suppliers? Did they ask where their stuff comes from? You can be upset, but like, garbage in, garbage out. Pcbway is really good for what it is, but they're only going to do as well as you force them to. They don't know whether your primary motivator is "cheap" or "legit". Most of their customers only care about the former. Especially at the tail end of a supply chain crunch
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Apr 26, 2024 21:21
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Exactly - I'm not really bothered as it's a bit of a gamble. This isn't the first time they've done something wrong (though last time it was just using the wrong IC entirely - same 74 series chip but different parameters so it'd burn out being fed the wrong voltage in a few minutes, which they also blamed on the mystery "suppliers") and they'll give me a refund on the parts + an amount to cover extra effort in fixing it. Though last time they did also offer to fix it, so I'll be interested to see what they actually say this time. It's such a saving over the US companies I've used before that even with the need to swap out those chips (which I already have a stock of) it's still going to have been cheaper. The real main issue is my SMD soldering is shoddy, but it's also a skill I want to improve, so I can live with that aspect. I've also actually sent them parts before too, which obviously makes it much more likely it'll be fine, so possibly for more exotic parts I'll just do that again next time. The first time I did it I was a bit worried they might just steal my parts, though, as you need to send extras in case there's trouble. e: I will say I am actually mildly interested in who PCBWay's suppliers are. There's hints on their site they'll use Digikey/Mouser but during the semiconductor shortage they were also able to source seemingly legit CPUs/etc. that weren't in stock anywhere I'd buy anything from. They wouldn't tell me when I asked. Charles Ford fucked around with this message at 22:15 on Apr 26, 2024 |
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Apr 26, 2024 21:27
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They definitely buy most of my parts from digikey - that's what takes three weeks to clear their customs
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Apr 26, 2024 22:24
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Speaking of aftermarket chips, does anyone know anything about *selling* into that market? I have maybe $5k worth of STM32F4xx chips at work that we bought when they first started appearing on the market after covid. They weren't the exact model I wanted but they could be made to work in a pinch and after two years of absolutely NOTHING being available we just said 'gently caress it, buy them all' and ended up only using a handful before the processor I really wanted started being commercially available again. So I have ~350 factory new processors that I'll almost certainly never use, it would make sense for our lab to sell them off as surplus and get a bit of cash back if we could, but I have no idea about where to even start looking for reputable buyers. Also I'm sure the university I work for is going to have some major red tape involved in trying to surplus a bunch of non-trackable items.
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Apr 26, 2024 23:02
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Cyril Sneer posted:Quick question. I lost the IR remote for this RGB LED string: You didn't actually ask a question  Anyway that says it requires an RF remote, not an IR remote, so that's probably why the others didn't work 
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Apr 26, 2024 23:05
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PDP-1 posted:Speaking of aftermarket chips, does anyone know anything about *selling* into that market? eBay?
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Apr 26, 2024 23:12
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Shame Boy posted:You didn't actually ask a question Hah, good catch. Yeah, I think you're right. I never realized they even used different technologies for this.
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Apr 26, 2024 23:33
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Cyril Sneer posted:Hah, good catch. Crude RF transmitter/receiver hardware has gotten cheap enough that a lot of things that previously were IR now just throw that in there instead. Confusingly they sometimes just re-use the plastic mold for the remote, and to fill the hole at the top where the IR LED would have gone they put a normal LED that just blinks when you press a button.
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Apr 26, 2024 23:40
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Anyone have a versatile charger they're happy with? I need to charge a variety of 18650 lithium and the like, sometimes SLA ups batteries below 10Ah, that kind of stuff. * I have a lovely one meant for RC/drone lipo packs, which works ok for those specifically, but can't tweak voltage limits on different chemistries, the fan is dying, and the UI sucks. * I have a really good victron charger for car batteries or larger sealed lead acid, but it only has 3A and 10A settings, and SLA batteries below 12Ah or so shouldn't be charged above 2A. * My benchtop power supply will oscillate weirdly around the CV/CC transition point as a battery charges, and I'm worried about it being damaged. I suppose as it nears the CV setpoint, it backs off the current from the CC limit, which causes the voltage across the battery to drop slightly, which lets the current rise again, and so on in oscillation. Also a regular benchtop supply doesn't do absorption phase time limiting and backoff to float, etc..etc.. The main things would be having actual charge profiles with bulk/absorb/float and so forth, as well as actually customizable current limits and voltage setpoints as weird chemistries come and go.
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Apr 27, 2024 21:32
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I would like to confirm/deny my hypothesis about why this lamp stopped working. I have this USB work light https://assets.cdn.jula.com/preset:...=19790101000000 https://www.jula.se/catalog/el-och-belysning/armaturer/arbetsbelysning/arbetslampor/batteridriven-arbetslampa-led-024720/ It runs on a rechargeable battery and charges with USB-C A few days ago my girlfriend plugged a USB-C laptop charger into it. It ran for a minute or so and then went out and now it won't turn on. The specs for the lamp says "Input: 5V 1A" and the laptop charger says "Output: 20V 3.25A / 15V 3A / 9V 2A / 5V 2A" So my guess is that the laptop charger gave it 5V and 2A and fried it due to too many amps? Pictures of the disassembled lamp and of the charger: https://imgur.com/a/Dh4wOmN I can't see anything that looks fried though. Would this be something that could be fixed with some tinkering?
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Apr 27, 2024 21:47
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USB-C stuff negotiates voltage levels and poo poo before turning on the juice, so that should work fine. USB-C laptop charger powering a desk lamp is A-OK.
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Apr 27, 2024 23:16
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A power supply never gives more than the device "asks for". That lithium cell can deliver dozens of amps, but the circuitry ensures that there will never be too high of a current flowing through the LEDs. There are exceptions - extremely dodgy AliExpress/wish/temu devices that don't have an actual charge controller for the lithium cell - but this device looks like it has some generic charge regulator IC (by looks - i haven't verified it with the datasheet) so you can hook it up to a 100a power supply and it will still be fine. The only thing i can think of, is that the power supply does not correctly switch between voltages. Measure.to verify. Also check to see if the cell isn't deep discharged. Sometimes the charger locks out in such a case.
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Apr 27, 2024 23:21
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LimaBiker posted:Also check to see if the cell isn't deep discharged. Sometimes the charger locks out in such a case. I think it could just be this - if it was switched on and charging, the LEDs probably used more current than the battery was receiving from the charger, so despite being "on charge" it went flat. This could be because it didn't correctly ask the laptop power supply for 5V 1A with the proper USB process, so the laptop followed the USB spec and only have it 250mA. This is a common issue for cheap electronics as they don't want to pay for a chip to do USB power negotiations, so both the charger and device just offer 1A without the negotiation. I can't think of any reason why that charger would've damaged the device though. I think it's extremely unlikely the laptop charger put out more than 5V - the USB PD spec is designed specifically to stop that happening, and USB laptop power supplies are either compliant or need to be recalled.
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Apr 28, 2024 04:56
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