Re: DC coil

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

Original poster: "charles rakes by way of Terry Fritz <twftesla-at-qwest-dot-net>" <cdrakes-at-ipa-dot-net>

I give up!! On trying to make the drawings....they both looked correct when
sent, however, like the in the movie the "FLY" it didn't arrive as I had
emailed it.  Sorry for the added confusion.  Charles
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, November 05, 2002 2:07 PM
Subject: Re: DC coil


 > Original poster: "charles rakes by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <cdrakes-at-ipa-dot-net>
 >
 > I'll try and make a drawing of the two TC circuits that I used.
 > NST Sec.
 > 0------------->|-->|--------|
 > 0                 diode string      |
 > gap
 > 0-----gnd.
 > |----------------------------||||||||-------o
 > 0                                         |                     ___|___
 > o
 > 0               diode string        |                     ______     cap
 > o pri coil
 > 0------------>|-->|---------|
 > |---------------------o
 >                                                                     gnd
 >
 >                          Full wave bridge
 > 0----------------|---->|---->|----|
 > 0                        |                        |
 > gap
 > 0----gnd            |
 > |------------|--------------|||||||||--------o
 > 0                        |                        |                   |
 > o
 > 0------|---------)---->|---->----|           ____|____
 > o  pri
 >             |             |                                    _________
 > cap                         o
 >             |              |-----|<---|<----|                   |
 > o
 >             |
 > |-------------|---------------------------o
 >             |---------------|<---|<---|
 >
 >
 > Boy, I hope the two drawings will do.  The top circuit works great with 21
 > inch streamers, however the bottom circuit does not perform at all.  The
 > only thing different between the two circuits is one used a full wave
 > rectifier circuit with the transformer's center tap as gnd giving about
1/2
 > have of the output voltage that the second circuit produces.....the bottom

 > circuit only change is to a full wave bridge circuit.  Must be a simple
 > explanation....but I've not found it.  Any clues?  Thanks once again.
 > Charles
 > Orinal Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Tuesday, November 05, 2002 9:03 AM
 > Subject: Re: DC coil
 >
 >
 >  > 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
 >  >  >
 >  >  >
 >  >
 >  >
 >
 >
 >