RE: high voltage measurement w/ divider

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "brianb by way of Terry Fritz <teslalist-at-qwest-dot-net>" <brianb-at-antelecom-dot-net>

Guys,

Be careful. A failure of one resistor here will most likely cascade down the
string turning all the resistors and associated wiring into an exploding
wire experiment with shrapnel flying everywhere. Carefully think this
through and provide plenty of safety margin before proceeding...

If you want to see what an unexpected failure scenario can do check out
http://www.briananddebbie-dot-com/images/Backyard%20Science/Quarter%20Shrinker/A
ccident/accident.htm

Regards,
Brian B.



<BIG SNIP>


 >>Also, I think these are 1/2 watt resistors and if my math is
 >>right, they should be dissapating 1 watt when the caps are
 >>charged to the full 10 kV (10*4 V/10*8 Ohms= 10*-4 amps or
 >>0.1 mA and therefore 10 kV X 0.1 mA = 1 watt. I think this
 >>doubling of their wattage rating on such an intermittent ba-
 >>sis should be ok?

<more snipage>

   >       Consider that a failure of the bleeder leaves a
   >       safety hzard.  Failure of the divider can blow the
   >       meter.  If overrating the resistors, make sure
   >       they are cooled, either passively (not enclosed)
   >       or with a fan...
   >
   > --
   >         best
   >         dwp