A lot of people start with a PC power supply. You get most common voltages (12V/5V/3.3V) with plenty of current. The only thing that's missing is current limiting.
(but glass fuses are cheap!)
Thanks for pointing this out. I've search some information about how to do that. I don't really like the one in instructables though, looks somewhat unsafe to me. Meanwhile this one looks good:
He made the modification truly separated from the PSU, so kinda modular design, I like it. He basically can plug and play the PSU into his "bench adapter".
I have 2 unused desktop computer laying around. One is my father's old desktop (I think it's 20 years old, I remember it has Windows 95 OS), the other one is not too old. I decided to take the older PSU, I might want to revive the other desktop, it still has some data that haven't been copied.
So I tear it down, pics below, it said Seasonic SS-200A-200W on the case. Now I hope that doesn't mean 200 Amps? It might be very well killing me if I do something stupid with it!
Aside from that, no other written instruction in the case. So I don't know what color give what voltage. I check the inside to see any burns or something like that, can't find any. I can't really remember why my father stop using this computer, not sure if this PSU is still alive.
The jack that connects to the motherboard doesn't seem standard to me, it divided into 2 jacks. I don't know if I can find a matching socket for that.
That's all I can do today, I'll find some more information and continue when I have more time.
Probably I will make a new thread for this later