power transformer b+ question

[funkmeblue]

what kind of b+ should I expect to get from a 120v 60hz 180-0-180(250 ma) power transformer with a solid state rectifier? thanks

[Phil_S]

It should be roughly 1.4*180*~95%= ~240vdc. It could be a bit less if the HT winding is "soft" and possibly a bit more if it is "hard". That is a ball park number and it will vary according to the circuit you supply with it. With 250mA capacity, it should hold up relatively well.

This is a nice beefy tranny @ 250mA. Use a doubler and you can still milk a solid 120mA @ ~450VDC if you like.

[funkmeblue]

thanks man, I'm actually looking for about 250 volts for a push pull class a circuit.

[Andy Le Blanc]

depends on the style of supply. If its like a fender with the center tap to ground
its a full wave capacitor input, you'll get a peak .71 x sec. V ac , and an
average .45 x sec. V ac. with the current, I DC of 1 x sec. I ac.
If its a full wave bridge with a capacitor input where the center tap is not
connected, It'll have a peak voltage that's 1.41 x sec., and average that's
.90 x sec, and an I DC that's .62 x sec. I ac.. Use the total sec. V AC, 360.
This is from the "Hammond" "transformer selection guide".

[funkmeblue]

like a fender 100 uf then a choke

[Andy Le Blanc]

Yup, everything after the cap is the load.