Re: Question on bleed off resistor

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

Original poster: "Scott Hanson by way of Terry Fritz <teslalist-at-qwest-dot-net>" <huil888-at-surfside-dot-net>

"Those resistors are way, way too big."

Actually, your resistors are way too "small" (low) in resistance value.

You need a really "big" (high) resistance value, in the tens or hundreds of
megohms range, instead of the 2000 Ohms you can obtain from your
series-connected 500 Ohm resistors.

Regards,
Scott Hanson

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, July 21, 2003 4:50 PM
Subject: Re: Question on bleed off resistor


 > Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<dhmccauley-at-spacecatlighting-dot-com>
 >
 >
 > Those resistors are way, way too big.
 > Even at best bet with 4 of those resistors in series you are looking at
2000
 > ohms -at- 400 watts.
 > With 7500VAC, you are talking almost 4A continuous across the resistors
(if
 > the power supply could actually supply that much)
 > Even if the supply could handle that current (which is cannot), the power
 > dissipated would be about 30,000 watts ! ! ! !
 >
 > For bleeders at high voltage, you need something in the high megaohms.
 >
 > Something 10,000,000 to 100,000,000 (10meg to 100meg) ohms depending on
the
 > voltage and power of the resistor.
 >
 > In MMC capacitors, we typically use 10Meg ohms across each capacitor.  So
 > its not uncommon to see 50meg to 100meg bleeder resistance across
 > an MMC array.
 >
 > But, 500-2000 ohms is waaaayyy to big!
 >
 > The Captain
 >
 >
 >  > I have a single .02MFD (80KVDC) capacitor I will be connecting to a
 > 7500/60
 >  > NST as part of a tesla coil tank circuit.  The output of the
transformer
 > is
 >  > 540 Watts.
 >  >
 >  > My question is, what size resistor can I safely get away with to bleed
off
 >  > the charge in the capacitor?  I have 3 or 4 500 Ohm 100 Watt resistors
 >  > lying around I would like to make use of.
 >  >
 >  > Thanks in advance,
 >  >
 >  > Tim M.
 >  >