Re: Homemade Voltage Divider

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Original poster: "D.C. Cox" <resonance@xxxxxxxxxx>



I would advise you consider picking up a cheap 
0-100 volt range analog meter and not use your 
good digital meter for this purpose.  You can 
pick one up from Fair Radio Supply (surplus) for 
about $7.00.  Better than blowing up a digital.

5-10 watts of dissapation is about right for the 
metering resistors.  Using a bunch of 1/2 or 1 
watt units in series will work well.

Dr. Resonance



Hi all,

I am pondering a way to reliably measure 10 KVDC
across the terminals of (2) 100 µFd energy dis-
charge caps that I plan to build a quarter shrinker/
can crusher project with. I will have up to a total
of 450 µFd at 10 kV when I get 2 other 120
µFd, 10 kV caps added to my collection. Anyway,
I was originally going to just use my Beckman HV
probe in combo with one of my DVMs to monitor
the voltage at the cap terminals to insure that I
do not overvolt the caps, since my HVDC supply
can go up to about 20 kVDC. However, I believe
the HV probe isn't desinged to be used like this
as its ergonomics lends it for hand held operation
so I was thinking of getting some 10K or 100K
carbon resistors and building a 100 resistor di-
vider to get a 100:1 reduction to safely
read 10 kV on my DVM as 100 volts. What
are the best resistance values to go for 10 K
or 100 K? A 1 Meg total with 10K(X100) would
still allow 10 mA of current flow at 10 kV and that
would translate to 100 watts (WOW)! I suppose
that I just answered my own question- don't think
(100) 1/4 resistors would take much of that! Better go
for 100 K per resistor, that would only allow up to 1 mA
of current flow at 10 kV and 10 watts. I believe 10
watts spread over (100) 1/4 watt resistors would work ;^)
Any comments or suggestions?

David Rieben