On Wed, 09 Apr 2008 14:22:42 GMT, mike wrote:


Sometimes there's a bleeder resistor on the output of the supply.
Often, it's made up of several series resistors.
Sometimes you can measure the ripple across the bottom resistor and
do the math. Or just install another resistor in the bottom
of the bleeder chain.

Or just unhook the cap, drive it with a pulse generator and look at it on
the scope. The shape of the waveform will tell you the capacitance
and ESR of the cap. If the cap is good and the diodes are good, there
ain't much else to look for.
mike

There are two series bleeder resistors (120K 3W) on the output of the
HV supply, with an electrolytic across each one. If you ground the
bottom of that chain, you get 600V output. The 275V supply is placed
in series with the HV supply for 900V output by moving the fuse from
one location to another. I could send you a PDF of the schematic if
you would like.

Dick
** Posted from http://www.teranews.com **