Bench PSU made from an old PC power supply (by alaric)
My first PC compatible was an actual PC. As in, the original IBM PC - not even an XT. It died a death, but I salvaged the power supply from it, with the nice red switch, to be a bench PSU for my electronics experiments:
It supplies -12v, -5v, 0v, +5v, and +12v. Which served me well for some years, but these days, everything's 3.3v or 1.8v. And my termination setups - first wiring directly into the row of screw terminals on a breadboard, then later a bit of wood with metal strips nailed to it so I could attach croc-clips easily - all left something to be desired.
So I got busy and built this:
Complete with a power LED so I can see at a glance if it's live:
Inside it's quite simple. Most of the terminals are fed directly from the PSU via the black cable, but I added an extra wire for an earth connection to the chassis (which I checked was really earthed) for ESD wrist straps. I mounted 3.3v and 1.8v linear regulators on a bit of stripboard along with the LED and its series resistor, and hooked it into the 0v and +5v lines.
Job done. Now the last bit of major infrastructure I need set up is to get Ethernet into the lab so the PC I have in there for driving the dev boards can access the Internet and my version control system...
Electronics | alaric | 
Mon 11th May 2009 9:52 am
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