Converting an PC AT Style Power Supply Unit

Back in 2005 July when I was working on testing a lot of my SWASC boat parts I thought it would be handy in having a +5V and +12V DC Bench-top Power Supply Unit (PSU) handy.  After a bit of hunting around online, I found that I just had to put a load on one of the PSU pins, and it would stay powered up, without a load.

Here are a few notes on how I went about this.

Parts used:

• 10 ohm, 10W resister
• small switch
• Green LED

All the parts where dug out of my box of spare parts that I have collected over time.  I soldered the 10 ohm resister onto a red  5V wire and a black ground wire.  The on/off switch was soldered to a white wire and a ground black wire, which replaces the normal PC switch.  I don't have any notes or photos of the LED, but I think this was added sometime later and most probably just hangs off the +5V line and a black ground wire via a small 300 ohm (or so), resistor.

Here is a close up of the power resistor in place:

and here is a recent shot of the completed PSU:

Note: messing around with Mains voltage equipment is dangerous and should not be attempted unless you really know what your doing!