I then started looking at 12v bench power supplies but there coming up at around £35 which seemed a little excessive as it wouldn’t be used very often.
Then I remembered seeing an article about someone creating a bench power supply from an old atx psu. After some scouring different ways of doing it I decided to build one myself. You could use this for anything that requires 12v ie CB etc.
Although I only really need 12V I thought I’d add the 5V and 3.3V as well just in case I needed them in the future. I have no need for –5V and –12V but you can add them if you wish.
WARNING: You are dealing with mains electricity here, if you don't know what your doing do not attempt to carry this out, I accept no responsibility for damage/injury/death.
Wiring
Purple: +5V Standby
Green: DC On
White: -5V (not available on all psus)
Orange: +3.3V
Yellow: +12V
Red: +5V
Black: GND
Blue: -12V
Grey - Power is on
PSU’s sometimes require a small load in order for them to power up so some people add a 10 ohm >10 watt resistor between a red and black wire however I used an illuminated 12v switch which has the same effect.
LED switch green + black / Grey + black
First I grabbed an old 350W ATX PSU I had lying around as you can see it's capable of quite high loads.
Next whipped the lid off (this obviously invalidates your warranty) and had a look inside
next was to bunch up all the external wires and chop the connectors off
Then bunch them together by colour and zip tied
next mark and drill holes for the bananna plug posts
Fit posts and make hole for switch (nightmare)
Add ring connectors to wires by colour and put onto posts and wire up switch
All looks good
Replace lid and test
Label posts, Job done lovely jubbly
