What Should I Salvage from this Old PSU? - Page 1
Forum section: electronics / beginners

author: DW1961
author_rank: Frequent Contributor
timestamp: June 20, 2023, 07:09:33 am
content: Just wondering if I should salvage anything from this? It's just an old PSU I literally found on the side of the road while driving buy.

author: mengfei
author_rank: Regular Contributor
timestamp: June 20, 2023, 07:52:15 am
content: if your a DIY'er I guess those semi conductors would be of use, caps & ecaps would have degrade for the type of usage & inductors are rarely being used unless you have a lot of inductance project

author: Smokey
author_rank: Super Contributor
timestamp: June 20, 2023, 07:57:49 am
content: I would grab the toroid cores.Be prepared, as we have been discussing in the other thread, for a terrible PCB design with no thermal relief on anything that is super hard to desolder.

author: armandine2
author_rank: Frequent Contributor
timestamp: June 20, 2023, 08:03:43 am
content: Heat sinks etcmight be fun to know/measure what toroid ring cores you have.on Sunday I also picked up some electronics road kill, a small circular pcb which had an ADE7753 chip (Single-Phase Multifunction Metering IC with di/dt Sensor Interface) that looks undamaged.

author: magic
author_rank: Super Contributor
timestamp: June 20, 2023, 09:10:52 am
content: Note that one of the inductors on the secondary may be part of a mag-amp, not much useful for anything other than building a mag-amp.The blue inductor on the primary is probably part of active PFC, fairly substantial inductance like ~1mH and good for a few amps.It all looks like a decent PSU, but a bit old-fashioned indeed. Maybe from the 2000s or so. Some stuff may be broken, or it wouldn't get thrown out.

author: Gyro
author_rank: Super Contributor
timestamp: June 20, 2023, 09:33:26 am
content: There's very little to be honest. As others have mentioned, caps will either be already dead or will die from seal failure during the excessive heat and mechanical stress of removal. The inductors maybe, although there is a distinct limit to how many of those you're likely to need (unless you're in the habit of building big SMPSs!). The heatsinks won't be easy to reuse as they are probably solder-in tab types, and designed for forced air cooling (little better than Aluminium sheet in that respect). Possibly useful for just cooling bits on the bench rather than a PCB.Mosfets and rectifiers if you can get them out with minimal thermal and mechanical stress, but the rest is pretty much junk, sorry.P.S. Bits from the case are probably the most useful, IEC connector switch, fan. People have been known to re-use PC PSU cases for various projects, but you probably need to avoid anything mains because the case holes and slots are too big.

author: Kleinstein
author_rank: Super Contributor
timestamp: June 20, 2023, 09:39:05 am
content: It depends on what part you aready have and what type of projects one is interested in.It could be as little as the srews.

author: RoGeorge
author_rank: Super Contributor
timestamp: June 20, 2023, 11:00:02 am
content: Pretty much everything worth salvaging if you are into electronics. Except maybe the electrolytic capacitors, which might have developed high ESR, though they look OK from the picture.To give a few examples from what I've reused already from former PC power supplies:- power double diode, to protect the lab power supply while charging a car battery- TL413 voltage reference/stabilizer, did an audio amplifier- magnetics, made a diode ring mixer and a directional coupler (good enough for low frequency RF)- radiators, for a MOSFET battery discharger- wires, real copper thick wires good to 10-100A, copper wires are expensive and hard to find- power resistors of low values, already aged and good for current shunt measure/protection in a DIY power supply- optocouplers, mains filter, various resistors/capacitors, thermistors, etc.

author: DW1961
author_rank: Frequent Contributor
timestamp: June 20, 2023, 05:10:12 pm
content: Quote from: mengfei on June 20, 2023, 07:52:15 amI've not even going to try to save the caps. hard to test them correctly and bleh

author: DW1961
author_rank: Frequent Contributor
timestamp: June 20, 2023, 05:12:16 pm
content: Quote from: magic on June 20, 2023, 09:10:52 amOh it was definitely fried. There was some sort of input power daughter card on it and it was crispy along with the caps on it. I think it's a 2008 model.

author: DW1961
author_rank: Frequent Contributor
timestamp: June 20, 2023, 05:15:44 pm
content: Quote from: Gyro on June 20, 2023, 09:33:26 amI actually stripped all of the wire from the leads out of it. Got about 30 feet of wire at 18 to 20 AWG. lolWhat about the transformers?

author: RoGeorge
author_rank: Super Contributor
timestamp: June 20, 2023, 05:59:22 pm
content: The small one is usually for a mains to +5V standby, a small standalone switching power supply (its max current is usually typed on the box, the +5Vstb current). The big one is also for high frequency, usually has a thick multistranded coil and a few other turns with solid wire.The magnetic cores alone can be hard to source and expensive when you need them. Can be used in other projects, too, for example to power them from a frequency generator to make a curve tracer, or maybe an injection transformer, etc.The metal box, if you still have it, is also reusable as a shielded enclosure for other circuits, plus it has a mains cable connector already embedded, in case you need it.Usually I keep former PC power supplies as they are, without bothering to strip them in advance. It's easier to locate spare parts from a PCB, than to search through scrap boxes full of all kinds of components.

author: LinuxHata
author_rank: Frequent Contributor
timestamp: June 20, 2023, 07:48:46 pm
content: HV mosfet and APFC choke at least.

author: DW1961
author_rank: Frequent Contributor
timestamp: June 25, 2023, 02:29:10 am
content: Quote from: magic on June 20, 2023, 09:10:52 amIs a mag amp what is used in soldering iron stations, older ones I guess, since now they are mostly digital?