Re: high voltage resistors

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

Original poster: "Crow Leader by way of Terry Fritz <teslalist-at-qwest-dot-net>" <tesla-at-lists.symmetric-dot-net>

Kanthal Globar makes high power pulse rated (as in highpower pulses, not
continous rating) resistors. I saw some at a trade show, and their
resistance range was too low for use as bleeders, but sound about right for
what you want.

their site http://www.cesiwid-dot-com/

KEN

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, January 20, 2003 10:36 PM
Subject: Re: high voltage resistors


 > Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>
 >
 > Hi Mark,
 >
 > 20,000 volts across a 35kOhm resistor is a stunning 11.5kW of power =:O
 >
 > I guess it is "pulsed", but beware that kind of power can rip a resistor
to
 > shreds over time.  Good thing Malcolm is on his long vacation, or he would
 > be all over our cases :o)))
 >
 > For the voltage, you need about 2 inches between the terminals to be
 > "really" safe.  For the power, you needs lots of surface area.  But it is
 > less than one amp, so we are in the thick film region.  DigiKey page 734
 > and 725 has thick film resistors.  Something like two SM204J15K-ND's may
do
 > it (page 725 of current cat.).
 >
 > However, huge power pulses can be messy, so beware...  You may be best off
 > with a bunch of cheap 1/2 watt resistors like we use in MMCs...
 >
 > Cheers,
 >
 >          Terry
 >
 >
 >
 > At 08:50 PM 1/20/2003 -0600, you wrote:
 > >Hello, all!
 > >
 > >I'm looking for some inexpensive resistors that will stand off 20kV
 > >pulses.  I have
 > >no objections to using two or three in series.  I need a value of
 > >30-40kohm.  I am
 > >currently using 3 1/2W resistors in series, but question the longterm
 > >standoff
 > >ability.  I have been considering the Ohmite OY series - 2W ceramic
 > >composition
 > >that are about .75" long and .3"diameter, available from Digikey.  But at
 > >about a
 > >buck each, I'd rather not spend $40 to discover they won't work!
 > >
 > >Thanks,
 > >
 > >Mark Broker
 > >Chief Engineer, The Geek Group
 >
 >
 >