On Sun, 16 Jul 2000 12:09:59 EDT W7lr@aol.com writes:
>
>We all know of wattage ratings for resistors - I'm interested in specs
on the
>voltage ratings of large resistors. 2 watt carbon resistors and 1 watt
>carbon film resistors are rated at 500 volts. I presume that is to
limit the
>voltage gradient or stress across the resistor so that it doesnt act as
a
>fuse or firecracker. What about large resistors often used as bleeders
on hv
>power supplies? I use 200 watt resistors in series and have never had
any
>problems. I assume they can stand hv due to their long length, about
10"
>long, to spread out the voltage gradient. Does anyone have any specs on
>their actual voltage rating? 73 Bob W7LR
Hi Bob,
Yes, it all has to with the voltage gradient and, if applicable, the
rate of change of the applied voltage.
The actual voltage ratings vary somewhat depending on the manufacturer
and the construction details... but, a conservative "rule of thumb" for
the large ceramic style resistors is 500V per inch of winding.
73,
Marv WC6W
*
________________________________________________________________
YOU'RE PAYING TOO MUCH FOR THE INTERNET!
Juno now offers FREE Internet Access!
Try it today - there's no risk! For your FREE software, visit:
http://dl.www.juno.com/get/tagj.
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|