Re: DC coil

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

Original poster: "Daniel Barrett by way of Terry Fritz <twftesla-at-qwest-dot-net>" <dbarrett1-at-austin.rr-dot-com>

     Not sure how you have it wired, but if you are just feeding the output
of your bridge rectifier straight into your MMC, as if you just inserted the
bridge between the NST and MMC, it won't work well. The problem is that
after the gap fires, the voltage on the MMC swings reverse. This forward
biases the bride diodes which burns off most of the MMC's charge in the
diodes instead of the primary. The solution is to install a great big choke
between the bridge and the MMC.
db

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, November 04, 2002 8:36 PM
Subject: DC coil


 > Original poster: "charles rakes by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <cdrakes-at-ipa-dot-net>
 >
 > Got a ?  I'm trying to get back into Tesla coil building, as I have a
 > little more time now, and throw together a simple DC coil using a
 > 15Kvolt  30ma NST with a full wave rectifier arrangement feeding the .02uf
 > tuning capacitor.  With the transformer's center tap a ground I figure I
 > was getting a little over 10k volts DC across the capacitor.  The coil
 > produces about 21 inch streamers with this set up.  So I figured if I
 > doubled the DC output voltage I  with a full wave bridge rectifier the
 > voltage would double.  Also the tuning should not change much,
 > right?  Anyway I put the circuit together and did increase the DC output
 > voltage, however the coil's output is only about 1/2-inch sparks no matter
 > how I try tuning it.  Am I missing something very simple.  Did revert back
 > to the full wave circuit and had good response again?  Any ideas?? Tx
Charles
 >
 >