Need a cheap high current power supply?
Use an old (or new since they can be pretty cheap) computer power supply as a bench top power supply rated for | 17A @ 12V || 38A @ 5V || 28A @ 3.3V || 0.5A @ -12V |
To turn an ATX power supply on, look for a thin green wire on the main connector, if you short this wire to ground (black) it will turn the power supply on until you remove the short. The power supply should identify the voltage and current rating of each coloured wire as the one I used does, but if not then the voltages should just a multimeter away and the current ratings should be readily available if you look up the relevant power supply’s specifications.
These power supplies usually have some internal protection but I highly recommend adding fuses to each voltage supply. I chose to use 10A fuses for each supply rail except -12V which is only rated for 0.5A and was fitted with a matching fuse. With standard fuse holders fitted you can also do some crude current limiting when prototyping by fitting low current fuses (better to blow some cheap fused than to fry your project).
I chose a DPST paddle switch for turning the supply on and off, the one I picked had an inbuilt 12V light but this was very dull so another indicator LED was fitted next to the paddle.
As with anything you make as a hobbyist, make it 2-3 times safer than you think it should be.