Re: Zener SSTC?

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

Original poster: Mike Poulton <mpoulton-at-mtptech-dot-com> 

Tesla list Wrote:
 > Original poster: Chris Roberts <quezacotl_14000000000000-at-yahoo-dot-com>

 > Hi everybody,
 > We all know that a conventional tesla coil uses a spark gap that fires and
 > switches the current whenever the voltage builds high enough, but has
 > anybody ever thought about using zener diodes to replace the spark gap?
 > Zeners do the exact same thing,

Well, there is a very important difference between zeners and spark
gaps.  Zeners maintain constant voltage across them once they start to
conduct -- a 5V zener begins conducting at 5V and continues dropping
5V at any current.  Spark gaps have negative resistance.  The initial
voltage required to cause breakdown is much higher than the conduction
voltage.  As soon as the gap breaks down, it drops only a few volts,
and continues to do so until the current through it ceases.  This is
what allows oscillation and effective power transfer in Tesla coils.
A coil with a zener for a spark gap would quickly dissipate all of its
energy in the diode.

-------------------------------------------------
Mike Poulton
MTP Technologies
mpoulton-at-mtptech-dot-com
KC0LLX (70cm AM ATV, 33cm/12cm FM ATV, Omaha, NE)