Re: What size capacitor should I use? - voltage ?

> Mariss has a formula that is conservative, and WORKS:
>
> C=80000 x I/E where C is in microFarads, I is in Amps, and E is in

Volts

>
> So in your case, I would look at 80000*12/70 or 13714µF and round

up to the

> next highest value with a voltage rating of at least 100V

I look for a cap that is about 30% greater in voltage. I have read
that the back EMF can spike 15% over the power supply.

I look at the voltage as 130VAC in from the street (highest probable
voltage) and 105 in from teh stree (brown-out conditons) and double
check that those extreems will not burn things up.

Can anybody offer a more correct method than my fudge factors ?

Dave