Re: KV meter

["Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Tesla list wrote:
> 
> Original poster: "David Euans" <davidwe-at-telocity-dot-com>
> 
> I am trying to build a 50 KV high voltage meter for directly measuring
> the voltage from my various high voltage transformers.  I have tried
> using a 100 microamp full scale DC meter with one 250 (32 KV) megohm
> resistor on each leg and an 80 KV diode string (four 20 KV units)
> directly off of one side of a 9 KV neon sign transformer in series with
> one of the 250 megohm resistors, but I get faulty readings each time.

Make an attenuator first, and measure the resulting low voltage with
a conventional meter. You can even dispense the high-voltage resistors
and use a capacitive divider. For example, make a simple Leyden jar 
capacitor with 100 pF of capacitance (very easy to sustain 50 kV with
this) and connect in series with it a normal low-voltage nonpolarized 
capacitor with 1 uF of capacitance.
This makes a 10000:1 attenuator with low-impedance output. Measure the
AC voltage over the 1 uF capacitor. 50 kV will appear as 5 V. The 
attenuator will drain 1.9 mA from the transformer at 60 Hz.

Antonio Carlos M. de Queiroz