[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: high voltage probes



Original poster: ant17-at-optushome-dot-com.au 

hi guys i made my self a 1000:1 voltage divider and it works great for
measure hvdc from a flyback or cw voltage multiplier but i have tried it on
my marx generator before and in the process kill my expensive dmm. The
problem with measuring marx impulse voltages is that the sparks they can
produce are so long that they just jump over any resistors ,that are in your
divider so it is pretty risky to your test equipment under any
circumstances. But if you are going to try it i would suggest using really
long commercial resistors or use lots of small resistors and stick them in
some conduit seal the tube and then fill it with oil that way the spark
can't jump over it so easy.so if you decide to try it i would go that way
but don't try it with any thing expensive that one  i learned the hard way.
cheers Anthony


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, 28 September 2003 12:01 PM
Subject: Re: high voltage probes


 > Original poster: dhmccauley-at-spacecatlighting-dot-com
 >
 >      I WOULD STRONGLY RECOMMEND AGAINST USING ANY TYPE OF ELECTRICAL TYPE
 > TEST EQUIPMENT TO
 > MEASURE MARX GENERATOR VOLTAGES DURING DISCHARGES unless the equipment and
 > measuring signal is completely isolated from
 > the marx generator.  During a discharge, there is huge high voltage
 > transients present on almost every part of the marx generator including
the
 > grounds.
 >
 > Dan
 >
 >
 >  > 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
 >  >
 >  >
 >  >
 >  >
 >  >
 >
 >
 >