Value of a leveling cap on the backside of a full wave bridge?

[rukiddingme]

How do you determine the best value of a leveling cap on the backside of a full wave bridge?


In this case, 12 volts 1.5 amps DC.

[MarkE]

The usual method is to determine the acceptable voltage droop, half cycle to half cycle.

The droop is approximately: V_DROOP ~= I_LOAD/(C*2*F)

The shortcut is: 8,333uF*Volts / Amp at 60Hz, or 10,000uF*Volts / Amp at 50Hz.

At 1.5A you need 12,500uF for 1V droop, 6,250 if you can tolerate 2V droop, 3,125uF if you can tolerate 4V droop etc.

[rukiddingme]

Thanks