AC power issue Help Pls

[Hellpit]

In my installation, I am using a PowerOne MAP80 power supply for my 5 and 12 volts needs.

I am also running a 120V AC fan to cool the enclosure, as well as a large relay to control my bleed down resistor on my Servo power supply.

The problem I'm having is that when ever I turn the AC fan off, my PowerOne supply momentarly shuts off, then goes back on again. The same issue when I switch my relay on and off. I think the power supply is browning out.

I know that in a DC circuit you would normally install a flyback diode, but what do you do in an AC circuit? I pretty sure the fan is generating power back into my main AC supply, and same with the colapsing field of the relay.

Help?

Thanks.

[Al_The_Man]

That is a switching supply so I imagine you are getting momentary pulse on the power line that is shutting it off, I would not have thought it would have been that sensitive.
An AC suppressor can either be a MOV Metal Oxide Varistor or a R/C snubber, the latter is usually used as it is easy to make up and is cheaper.
You need an AC rated cap, ~.1µf in series with 330ohm 1watt resistor.
Al.

[Hellpit]

Thanks Al, that is the direction I needed.

I'm also going to try re-wiring the fan and relays on double pole switchs to switch the hot and neutrals at the same time.

[Hellpit]

I built the RC snubber you described. Worked like a charm!

Thanks again.