HV Testing (was:Re: Newbie's got a dead 386)

From: Philip.Belben_at_pgen.com <(Philip.Belben_at_pgen.com)>
Date: Thu Nov 19 06:07:40 1998

> Another one - How do you test supplies and various heater controls that
have
> to float at 8Kv? I.E.: their common point is at 8Kv. Especially when
they
> are intermittent and you can't tell without the HT on exactly when it is
> acting up. VERY carefully float your meter at kV and be very sure you
don't
> touch the meter and don't do like I did and get to near the leads while
> operating the instrument while waiting for the intermittent to act up.
An
> 8Kv _at_ 5ma with 1ppm stability supply burns holes on the way in and out.
In
> the arm and out the finger.

I'd recommend:

1. Get one of those rubber holsters for the meter and allow only the
holster to touch the equipment.

2. Make some test leads out of EHT wire. The sort of stuff that's used
for the anodes of CRTs and things. Maplin used to sell it (haven't checked
recently), rated at 25 kV, and I'm sure other suppliers do too.

3. Failing no. 2, car engine HT leads may be useable, but most of them are
quite rsistive, so check the calibration!



Philip.
Received on Thu Nov 19 1998 - 06:07:40 GMT