[sdiy] ad633 fun, psu

[Ingo Debus]

harry wrote:
> For a dual... use the same bridge rectifier and two capacitors. The common
> point
> of the capacitors is tied to the center lead of the transformers.  The
> positive and negative voltages will not be equal because the inputs are not
> equal. But it will work.

I think this won't work. The standard
center-tapped-transformer-plus-one-bridge-rectifier dual power supply
uses both transformer windings for each output. If the two windings have
different ac voltage the unfiltered output voltages will have lower and
higher half-waves. The higher half-waves come from the winding with the
higher voltage and the lower half-waves from the other winding. If a
filter cap large enough is used, this becomes simply a half-wave
rectification, and the winding with the lower voltage (and its diodes)
isn't used at all.

Ingo