Yep. My mate, VK6WF, had a similar problem with his 4-1000a power
supply. There was insulation breakdown between the secondary and a
grounded electrostatic shield in the hv transformer.
It had worked just fine for 17 years and then one day, at switch on,
it went bang.
It did not show up with a ohm meter. It did not show up with a 1kV
megger. It was there though.
Lifting the grounding wire off the shield has solved the problem for
now. The in that the power supply works again. The transformer, of
course, is still sick and plans are in place to replace it very shortly.
73, Alek
VK6APK
At 03:52 AM 12/07/2011, Steve Thompson wrote:
>A problem in the transformer won't show up with a DVM - you'll
>need to hipot test it.
>
>If the transformer is the problem, you won't see it with the
>bridge connected and floating, only when the -ve end of the
>bridge is connected to ground - which might only happen when you
>hook up the caps?
>
>Steve
>
> > Yes, I checked for shorts & nada. The transformer, sans FWB & etc
> > performs flawlessly. The repaired FWB also is fine fed by the transformer
> > without the cap bank load...
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