We know what you’re thinking — yet another scrap PC power supply turned into a bench PSU. But look a little closer and you’ll see a nicely designed linear bench supply that just fits inside a gutted ATX case.
A lot of the items on [Medzik]’s BOM for this build are straight from the scrap bin. The aforementioned ATX supply case is one, as is the power transformer donated by a friend. Modules such as the 30V/2A regulator, the digital volt/ammeter, and a thermostat module to control the fan at higher power settings were all sourced via the usual suspects. The PSU boasts two outputs — an adjustable 0-22 volt supply, and a fixed 12-volt output. An unusual design feature is a secondary input which uses the 22-VAC supply from a Weller soldering station to give the PSU a little more oomph. This boosts the maximum output to 30 volts; one wonders why [Medzik] didn’t just source a bigger transformer, but you work with what you have sometimes. There are some nice touches, too, like custom-printed vinyl overlays for the case.
It’s a good-looking and compact unit with a decent suite of features, and you could do a lot worse when building your next bench supply. If it’s not your cup of tea though, just take your pick — tiny and yellow, built to last, or ensconced in Ultrasuede.
I have to try this. I have tons of power ???? atx cases. Great article.
Yes, once transistors became common, some of the most expensive parts for projects were cases, and power transformers. Those computer supplies make great cases, ironically I’ve built power supplies in some, not needing high current and not wanting the noise from the switching supply. So power transformers pulled out of consumer electronics went in, though increasingly such equipment now uses switching supplies. I even leave the switch (these were of that vintage) and the power cord socket. A piece if circuit board provides a front panel.
Michael
Great scott did a great episode on units like this. He used some off the shelf buck-boost converter to get from 12 to 3-24V I believe and used a LED power supply to get the 12V from mains.
Nice unit. I had something similar going but my digital ammeter/voltmeter was off wildly and could not get it to calibrate properly with the little pot on the board.
Excellent use of an ATX PSU case.
I have been wanting to make another linear bench PSU by rewinding and multi-taping a Microwave Output Transformer but switchers are so cheap and available and probably cost less than the copper I need to rewind the MOT.
Hi! Can you explain how to connect amperometer ? I buyed one and i saw two wires small size and three wires with hight size.. But can explain function of any wire ? I’ll want to connect to buck boost…thx
Can help me to understand wiring diagram of connection amperometer i can’t find over net wiring diagram …contact me For help danielea771@gmail.com thanks
Hy , I have send you a email with schematic