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Old February 2nd 05, 03:24 AM
Gary Schafer
 
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On 1 Feb 2005 08:06:26 -0800, "Mike Silva"
wrote:

Yes, both C1 and C2 are charged with 1/2 wave power (one pulse every
full cycle). However, it appears to me that the difference is that
they only discharge during one half-cycle of every full cycle. On the
charging half-cycle they are not also discharging, but they only
discharge on the opposite half-cycle. This is different from the 2x2
doubler, where both caps are charged on alternate half-cycles, but both
caps discharge during the entire full cycle. If I've analysed this
correctly, it seems that there should be some improvement in voltage
regulation over the 2x2. But I wanted others to look at the circuit
and offer their ideas on it as well.

73,
Mike, KK6GM



It is true C1 and C2 are not discharging while charging. But when they
do discharge on the other half cycle they are being discharged more
than they would be in a regular doubler circuit.
They still each have to supply 1/2 of the output load at that time to
recharge the output capacitor. The output capacitor is getting
recharged through C1 and C2 only and not directly from the diodes and
transformer. So in effect you have 3 capacitors in series for the load
rather than 2 in a regular doubler.

Although at first glance it would seem that the output capacitor is
getting part of its charge through some of the diodes, it only does so
on the first cycle at startup . After that the output capacitor is
charged to a higher voltage than the transformer supplies directly.
That keeps the diodes directly from the transformer to the output
capacitor reverse biased so no current flows directly from the
transformer to the output capacitor.

So the output capacitor ends up only being charged by C1 and C2 on
alternate cycles. So it would seem that performance would be worse
than a standard doubler circuit. Unless much larger capacitors were
used.

73
Gary K4FMX