RE: TC Part alternates

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

Original poster: "Michael Quarles by way of Terry Fritz <twftesla-at-qwest-dot-net>" <mquarles-at-qusion-dot-com>

Since I obviously don't have a modicum of understanding of electrical
theory, can you tell me the voltage rating requirement for the bleeder
resistors?  I, being limited in my understanding, would think you would need
resistors that can handle 2000v.  However on this board I see experienced
people recommending 1/2 watt carbon film resistors that have about 350v max
working voltage.

Others say no you need a 2000v resistor and they recommend metal glaze
resistors.

In my searching the metal glaze resistors have a higher voltage but nothing
near 2000v.  I have found thick film resistors that will handle 2000v but
they are rather pricey.

Thanks for your help.  I learn more each day.



 > -----Original Message-----
 > From: Tesla list [mailto:tesla-at-pupman-dot-com]
 > Sent: Thursday, December 19, 2002 7:44 AM
 > To: tesla-at-pupman-dot-com
 > Subject: Re: TC Part alternates
 >
 >
 > Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
 > <Mddeming-at-aol-dot-com>
 >
 > In a message dated 12/18/02 7:09:49 PM Eastern Standard Time,
 > tesla-at-pupman-dot-com writes:
 >
 >
 > >Allelectronics has the caps but the closest resistor I could
 > find there is:
 > >400 ohm/50 watt ceramic
 > >I could put 3 in an series to get 1200 ohms but what happens to
 > the watts?
 >
 >
 > Your composite resistor will be able to dissipate 150 Watts.
 >
 > >I also read I should use 10M ohm 1/4 watt 2000 volt bleed
 > resistors for the
 > >Geek Group caps, but isn't the 1/4 watt a problem?
 > >Isn't there a lot more than 1/4 of a watt going through them?
 >
 >         The power supplied TO the SYSTEM is not the power being
 > dissipated
 > (used up) BY each RESISTOR. The power being dissipated by the resistor is
 > E^2/R, where R is the resistance and E is the voltage drop across each
 > resistor.For say, 2000V drop across each cap, a pair of these in series
 > would each dissipate 1000^2/ (10^7 )=0.1 watts. Now 2000v across a single
 > 10M resistor  would dissipate 0.4 watts, in which case a 1/2 watt
 > resistor
 > would be a better choice.
 >         This points out why some modicum of understanding of electrical
 > theory is preferred before completing a coil.
 >
 > Matt D.
 >
 >
 >