Re: Terry's GM HEI Coil Update.

• To: tesla-at-pupman-dot-com
• Subject: Re: Terry's GM HEI Coil Update.
• From: Bert Hickman <bert.hickman-at-aquila-dot-com> (by way of Terry Fritz <terryf-at-verinet-dot-com>)
• Date: Wed, 18 Nov 1998 06:02:24 -0700
• Approved: terryf-at-verinet-dot-com

Tesla List wrote:
> 
> Original Poster: Terry Fritz <terryf-at-verinet-dot-com>
> 
> Hi All,
> 
>         Tonight I tested my new and improved Tesla coil made out of a
General
> Motors High Energy Ignition coil.  This new coil uses a brand new HEI coil
> and has much greater high voltage stand off capability.  

<SNIP>
>         The GM HEI coil is immersed in oil.  It was very noticeable that
whenever
> the coil fired, the oil would violently "jerk".  This is due to the high
> voltage charging the oil suddenly. 

<SNIP>

Terry,

Very interesting results, especially with the different breakdown
effects between positive and negative polarity! 

Re: the "jerking" - a more probable explanation is that the large
current pulses are actually creating large electromagnetic forces on the
primary winding itself, causing it to mechanically deform and then
rebound. The electromagnetic forces will simultaneously tend to increase
the primary coil diameter (sort of like internal magnetic pressure), and
reduce the primary's axial length. If you continued to increase the 
current, the primary winding would permanently deform. At much higher
currents, the forces would exceed the yield strength of the copper
itself, and the coil would "explode".  

-- Bert --

• Prev: High power HVDC cap design.
• Next: Need Help.
• Index(es):
  • Main
  • Thread