[GreenKeys] 120VDC power supply noise?

[Roy Morgan]

At 10:17 PM 10/9/2005, KC0NNC at aol.com wrote:
>Sounds like a Sola Transformer style of hook up.  The AC capacitor is  a
>resonating cap, and transformer and capacitor form a resonant 
>circuit,  providing a relative stable output ac voltage to present to 
>the  reci=tifiers.


This guess gets my vote!

>  It is normal for a sola transformer circuit to vibrate, I have yet to see
>(or hear) one that didn't.

Agreed.  If they don't make noise and heat they are not working right.

>  There are several tests one can perform,

I suggest putting a 60 ma load on it and varying the AC input voltage to 
see if the output DC changes (much). (Despite my occasional diatribe about 
the dangers of using Variacs on old radios, this is an ideal and proper use 
for one.)

Roy

- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
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