Voltage doubler no center tap

[darryl_h]

Not exactly nothing. Depending on which polarity comes out of the transformer on the first half cycle, one of the capacitors can see a big reverse voltage. Can the caps you are using handle it? Feeling lucky?

Not correct. The largest negative voltage either of the capacitors could theoretically "see" is the forward voltage drop of the diode which is in parallel with the cap.

[LOUDthud]

Not correct. The largest negative voltage either of the capacitors could theoretically "see" is the forward voltage drop of the diode which is in parallel with the cap.

How do the diodes clamp the voltage after they have been removed as suggested by JM?

[martin manning]

Interesting... Lots of doubler circuits using the two-diode version have been built and used successfully, but indeed the lower reservoir cap can see a reverse voltage situation for (worst case) 1/4 of a cycle when the input voltage starts high. So it seems only one of the four diodes is truly superfluous.

[darryl_h]

[img:280:215]http://www.daenotes.com/images/full-wav ... oubler.png[/img]

In the two-diode version, C2 does not see a reverse voltage when the input is high, because D2 is reverse biased during that half-cycle.

[martin manning]

But D1 is forward biased, and C2 sees that positive voltage on its cathode through the load.