Electronics Power switch for psu

I'm currently modding my first computer case. It's on oldie I got from a friend (better to practice on ). I want to replace the power button with a key switch. I've read articles on this, but they described it having two wires (black & white) , while mine has four (black, white, brown & blue). My psu is a Power Pro GT-230w. Anyone know what the other wires are for. I searched the net for quite a while with no luck.

thanks
blackdog

 

your power switch has 4 wires?

 

yes it has 4 wires. the label on the power supply reads black=L2, brown=L1, blue=N1, white=N2

 

can you trace the other two wires and see what they go to?

 

Ah, it sounds like you have an AT power supply. This could be a problem, as the switch is going to have to handle all current that the power supply is drawing, in your case, it's roughly 2A. (AT power supply switches determined if the supply was connect to AC or not, ATX power supplies are always on when plugged in, but the switch kicks on the rails needed to boot up the system)

Assuming you have an SPST keyswitch, then you're going to have to connect blue and white together (AC neutral) and wire up the switch between black and brown (AC live).

If you have a DPST switch, then you should wire both up to the switch. Just make sure you wire them up so the right wires connect to each other. Phase-to-ground faults can be nasty.

If you have a momentary switch, then you're pretty well screwed. Momentary to latching is a fairily easy process (D-type flip-flop IC with complementary output + a 555 timer), but since an AT power supply doesn't supply any power when it's off, you'd need an external power source to power the circuitry, which seems silly.

 

Thanks for the advice guys, but it sounds a little more complicated than I thought. I may have to re-think things for now.