> Only a matter of semanitics possabily but while it is a
> Full Wave Rectification "Method" to use a centertaped
> transfromer and 2 diodes a "Full Wave Rectifier" itself
> has 4 Diodes.

>>  A full-wave rectifier uses TWO diodes.
>>  A bridge doubler uses FOUR diodes.

TW> Not the way I learned it. A Centertapped transformer circuit
TW> uses two Diodes to get Full Wave rectification.
TW> But to get Full wave rectification from a NON centertaped transfer it
TW> requires four Diodes in a "Bridge" configuration.  I cannot see
TW> how 15 VAC in and a little less then 15 VDC(Input less doide loss) out
TW> is called Doubling.

MM>  So far, this discussion is all semantics and half-truths, and most
MM> of what said so far was incorrect.

MM>  In this particular discussion, we have a 'given', a 15-0-15
MM> transformer:

MM>  Using it with two diodes as shown in the two diagrams previously
MM> posted would give the 15VDC output as desired.

 Except that would be at the rated output
of the transformer. With lighter loading
the output voltage will be higher, up to
1.414 x actual AC RMS voltage. If 15 VAC
RMS then that would be 21.21 VDC.

MM>  To use that SAME transformer with a bridge rectifier would mean not
MM> using the center tap, and would therefore have a 30V output.

 That is one choice. The other choice is
to use the center tap of the transformer
and the (+) output of the bridge. Connect
the other two transformer leads to the AC
input terminals of the bridge as normal;
but, do not connect anything to the (-)
of the diode bridge. This will use two of
the diodes in the bridge. The other two
diodes (the ones connected together to
the (-) terminal) will not be used. They
are just stuck there in the same package.

MM>  Another consideration:  With the two diodes, only half of the
MM> secondary is driven at any given time.  With the bridge, the full
MM> secondary is driven fu time.  This could be important for cooling
MM> considerations.

 True, but the voltage is too high to be
of use (as it was originally designed) if
you use the bridge as you have suggested.

 TTYL.

 Robert

 * SLMR 2.1a * A husband is a lover who pushed his luck too far.
--- Platinum Xpress/Win/WINServer v3.0pr5