RE: Pulsed Tube Coil Work (questions)

what tetrode did you use? This is quite clever!
Also, when you refer to 3 pulses/sec are you
associating this with the time constant to charge
the DC filter cap? Is this rule of thumb? What
happens if you increase the rate?
John G

John W. Gudenas, Ph.D.
Department Chair of Computer Science and Mathematics
Aurora University, Aurora IL 60506
Office: 630-844-5539     Fax: 630-844-7830

-----Original Message-----
From:   Tesla List [SMTP:tesla-at-pupman-dot-com]
Sent:   Monday, March 08, 1999 6:38 PM
To:     tesla-at-pupman-dot-com
Subject:        Pulsed Tube Coil Work (with updates)

 Anyhow, to solve this problem, I used a tetrode tube for the main TC
 oscillator and fed a source of 600 volt, 60 Hz AC, through a dropping
 resistor, to the screen of the vacuum tube.  So the plate received
 pure DC, the screen received 60 Hz AC and the grid was connected
 in the traditional tube TC fashion.  Results were now excellent--the 
 oscillator starts gradually under the influence of the screen grid AC 
 and the sparks appeared just like the AC pulsed tube coil sparks.
 Since the system uses filtered DC, it is possible to use a small, 
 weak, transformer which slowly charges the filter capacitor over
 multiple AC cycles during TC "off" times.  Then, when the filter 
 capacitor is fully charged, the TC is turned "on" and the tremendous 
 stored energy in the filter capacitor is instantly available to the TC 
 which produces a giant spark pulse which partially depletes the filter
 capacitor's charge and the cycle begins anew.  I use about 3 
 pulses/sec which appears reasonably steady to the eye.