Topband: DX-100 adventure - progress

[Charlie Cunningham]

After reflecting on your point, that is obviously true, Tom, I would go
ahead and spend a few cents on some rectifiers to put across those
electrolytics!

Operating electrolytics in series is just something I don't do -except in a
voltage-doubler or a Cockroft-Walton multiplier.

Have a Merry Christmas!

Charlie,  K4OTV

-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Charlie
Cunningham
Sent: Saturday, December 21, 2013 1:32 PM
To: 'Tom W8JI'; 'Bill Cromwell'; 'top Band'
Subject: Re: Topband: DX-100 adventure - progress

Diodes across the electrolytics ro prevent reverse chargin would probably be
a good idea. 1N4007 1000 PIV, 1 A rectifiers should do nicely.

-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Tom W8JI
Sent: Saturday, December 21, 2013 1:02 PM
To: Charlie Cunningham; 'Bill Cromwell'; 'top Band'
Subject: Re: Topband: DX-100 adventure - progress

> BTW, Biii - tip/suggestion  - for those series-connected electrolytics 
> you probably should put a pair of equal value resistors - one across 
> each series capacitor, as the leakage currents will not be equal in 
> each capacitor in each series string and the DC voltage won't divide 
> equally across each capacitor unless you put individual "bleeder" or 
> "swamping" resistors across each cap in the series pair to equalize 
> the DC across each capacitor in the series!

It is worse than that.

With a single bleeder for two series capacitors, the capacitor with the
least capacitance will always be reversed charged upon every power down. So
even you have equal voltages by equal leakages, you have to add a parallel
diode or the discharge will reverse charge the cap with the lowest
capacitance value. 

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