Re: high power resistor

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jimlux-at-earthlink-dot-net>

for HV use, you'd be better off with series strings of low value hi watt
resistors than parallel combinations of high value hi wat resistors.  The
failure mode for wirewound resistors is a small open followed by an arc
across the open. In parallel, the arc would reduce the resistance of that
resistor causing it to take more and more of the current.  In series, the
other resistors would limit the arc current, and it would quietly just go
open.

Mind you, for safety dump resistors, I'd go the other way, because it is
more fail safe.

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, February 23, 2001 5:46 PM
Subject: Re: high power resistor


> Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<evp-at-pacbell-dot-net>
>
> Tesla list wrote:
> >
> > Original poster: "bob golding by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <yubba-at-clara-dot-net>
> >
> > HI All,
> >     I have been looking around for cheap source of resistors too use in
> > my DC power supply project. I have looked at the various options and
> > they are all outside my present budget. (around 150 dollars) this is for
> > a 1 kw 5 k ohm resistor. I want to try making one using nichrome wire as
> > this should be considerably cheaper. Anyone tried this?. It just rankles
> > to have to spend so much on a resistor :-(( Don't mind spending this
> > amount on something like a transformer on a cap, but a resistor?
> >
> > cheers
> > bob golding
>
> C and H Sales (Google Search) has 50k, 100 watt resistors for $7.00
> each.  Ten in parallel would be cheaper than your price.  Bet you could
> do better yet if you looked around some more.
>
> Ed
>
>
>
>