Spark Gaps

From:  John H. Couture [SMTP:couturejh-at-worldnet.att-dot-net]
Sent:  Saturday, April 11, 1998 2:28 PM
To:  Tesla List
Subject:  Re: Spark Gaps


  I agree with Antonio. Why is the Tesla coil called an air core transformer
if it operates as an induction coil?

  It is my understanding that the Tesla coil utilizes dampened waves and
resonance. The spark gap characteristics should optimize this type of
operation. The spark gap CLOSING is important for Tesla coils (Peak of the
voltage wave). The spark gap OPENING is important for induction coils (di/dt).  

  But why is quenching important for Tesla coils? The times that quenching
occurs are certainly different with fixed gaps compared to rotary gaps. One
should be better than the other.

  John Couture


At 11:56 PM 4/9/98 -0500, you wrote:
>From:  Antonio C. M. de Queiroz [SMTP:acmq-at-compuland-dot-com.br]
>Sent:  Thursday, April 09, 1998 1:11 PM
>To:  Tesla List
>Subject:  Re: Spark Gaps
>Jim Lux wrote:
>> 3) Faster interruption of the spark. As opposed to just waiting for the
>> current to go through a zero, the gap is physically separated. The sudden
>> circuit opening causes the voltage across the primary inductor to rise,
>> inducing a similar rise in the secondary. The faster the interruption
>> (di/dt) the more the rise.
>Do this really work? This would be like operating a Tesla coil as an
>induction coil. The theory saying that there is a great increase in the
>secondary voltage or a two-coil system after the opening of the spark
>gap (Corums) may be due to this effect (otherwise I don't see how).
>Antonio Carlos M. de Queiroz