my 7v/12v fanbus stuffed blew my power supply fuse, why, please help!

[Detoyminador_]

i built the 7v/12v fanbus switch project like the one at virtual hideout did but a little different. i had no off setting so it was just 7v/12v and i didn't fit the LED's. what happened was when testing it it worked fine, i started it at 12v switched it too 7v fine back to 12v but then i flicked both switches to 7v and my power supply died, the fuse went. it's a 235watt octek power supply. i'm pretty sure nothing shorted, is it because the 5v and 12v wire thing?

please help, thanx.

 

[Mikewarrior2]

The only thing I coudl think of, is that you either had too many amps being drawn into the +5 volt(highly unlikely, as most power supplies can handle at least 20 AMps on the 5+ volt side, even 235 W P.S.s) or you did indeed short it.

It may not seem like it was shorted, but all it would take is just a little bit and the fuse might go. It shouldn't be too hard to replace it, though. Just let the p.s. sit overnight to decharge ti a bit, and then go ahead and open it(I CANNOT STRESS ENOUGH taht you should be extremely careful. A lot of things still have a charge)

Then, the fuse should be fairly visibe.. pull it out, make a trip to your local radio shack and pick up a replacement... I dont' think you've done any other harm to your P.S.

And if you did blow out the fuse, I wouldn't owrry about it. You wouldn't be the first guy to do that .


Mike

 

[Detoyminador_]

also, the switches i used are rated 125v 1.5amp, is this ok?

 

[Mday]

they are fine. <-- swiches

are you sure it's a fuse, and not a short?

i have a fanbus that i made myself, and it had a short. even the one i made before this one had a short.

i use RCA jacks, so the short was in an rca plug...

 

[Mark R]

It sounds as if you had short circuited the power supply to ground. This is not impossible given the fault you described. I suggest you check your wiring very carefully.

The only other thing I can think of is feeding too much current back into the +5V line. PSUs are designed to output current from the positive supplies. By connecting fans between 12 and 5, you are injecting current into the power supply where it is not expecting it.