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>

That's good to know. Were they duds by chance any of the "high resistance"
resistors ohmite themselves admit are of poor reliability? I was amused when
I say that note on some of their datasheets.

KEN

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, January 21, 2003 10:44 PM
Subject: Re: high voltage resistors


 > Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<dhmccauley-at-spacecatlighting-dot-com>
 >
 > Unfortunately, ohmite resistors are very poor for HV pulse applications,
 > even though they may be spec'd to do so.  I recently designed a TWT grid
 > modulator system which in an
 > original design used carbon composition resistors (the old ones.)  Since
 > these resistors have long since been obseleted by all the original
 > manufacturers (although distributors still
 > carry them in stock), we were forced to make a different selection.  We
 > tried all HV pulse type resistors ohmite had to offer, but all failed
 > repeatedly under pulsed load conditions.
 > When I say failed, they failed within 100 hours of  testing.  We ended up
 > going to an IRC pulse duty resistor which proved satisfactory.
 >
 > Dan
 >
 >
 >
 >  > A source of resistors that I sort of gave up on for what I needed is
 > Ohmite.
 >  > They seem to have taken over the victoreen line of HV resistors and
have a
 >  > semi useful online inventory thing that let's you see what distributor
has
 >  > what in stock.
 >  >
 >  > They will make items not stocked just for you, but it's far from cheap.
 >  >
 >  > www.ohmite-dot-com
 >  >
 >  > KEN
 >  >
 >  >
 >  >
 >  >
 >  >
 >
 >
 >