[Amps] Voltage Doubler Regulation

[Jim Thomson]

Date: Sun, 12 Jun 2011 21:28:27 +0100
From: Ian White GM3SEK <gm3sek at ifwtech.co.uk>
Subject: Re: [Amps] Voltage Doubler Regulation

Richard Solomon wrote:
>I would like to look at ways to improve the Voltage Regulation in a
>Voltage Doubler Circuit.
>I tried Google, but didn't get much on the actual calculations involved.
>
>Since we have certain givens; such as The AC Line is what it is, the
>Plate Xfmr is what it is,
>the only variable in the equation would be the Capacitor value. Am I
>correct in that assumption ?
>

Many more variables need to be taken into account. Voltage regulation in 
a doubler circuit will always be poorer than in a similar full-wave 
bridge, and the series resistance of the transformer windings becomes a 
critical factor.

## I have 3 x drake L4B's  and  mating hv supplies.  2650 vdc on RX..
and  2500 vdc  with 800 ma  key down cxr.  They use a doubler.  The
xfmr is a small thing. Sec dc resistance is 10 ohms.   They used  8 x 200
uf caps.  I replaced em with 8 x 2500 uf  outboard caps.. [ and step start of course]. 
Dynamic regulation is superb on ssb... it doesn't budge.  Ripple dropped from
 3%...down to just .24% 

##  The hb supplies all use  dahl xfmr's  and  FWB... and also big caps in series.
10,000 uf @ 450 vdc.   They don't budge either.  Zip for  ripple on them. 

##  These boat anchor  plate xfmr's will work with a high C filter  too..and provide
decent regulation.... but they run hot. 

Later... Jim   VE7RF