Re: high voltage probes

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

Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com>

Hi Mark,

Consider "water resistors".  Or, plane wave antenna.  Just make a little 
flat "transmitter" antenna to get a better signal off what you want to read.

Directly connecting the Marx is scarry since the voltages and currents are 
so high that no ground can be trusted. Use a cheapo E-bay scope with lots 
of big MOVs on the power and stuff ;-))  I would simply "plan" on it going 
bad...  But once you get it going, it will seem easy ;-))  If the scope 
eats the output, it will also go right into the AC wiring as it happily 
cremates the scope.  So work on protecting the AC line stuff real 
well.  Might even consider running off a cheap old UPS power source....

Cheers,

         Terry


At 05:44 PM 9/27/2003 -0500, you wrote:
>I have a desire to hook our small Marx Generator up to an oscilloscope to 
>view the waveform across the rectifier during the discharge event.  A 
>while back we overvolted a 32kV rectifier we were using at "low voltage" 
>with only a little over 10kV cap charge.  In theory, only 20kVmax should 
>have existed across the rectifier.  I don't want a similar event with the 
>final 55kV rectifier when we run it at full voltage off a 15/30 NST.
>
>I was thinking of just making a 1000:1 resistive divider, which would work 
>for low frequency/DC, but I don't know how well that would work with the 
>MHz hash in the discharge.  Any opinions from the crowd?  I don't expect 
>the need to measure more than 25kV.
>
>Thanks!
>
>Mark Broker
>Chief Engineer, The Geek Group