Voltage peek?

[vince]

Hey guys

I just finished building an 8 ouput power supply. Each output is powered by a different transformer, like the Spyder at GEO.

I have one small problem though. I use a 100 mA/ 250 V fuse to power the 120V/12V transformers. I blew up a couple of fuses when testing the whole thing. I realized there was no short in the circuit. The problem seems to be coming from voltage spikes on the primary side of the transformers when quiclky turning on/off the circuit. I am looking for a solution to this problem... I know a diode is usually used in parallel with the winding to smooth the voltage spike, by maintaining the current, but that's not a solution if it is AC voltage...

[R.G.]

Make sure you're using a "Slow Blow" or "Slo-Blo" rated fuse. These have a time delay feature that keeps them from melting on initial transients.