Spark Gaps

From:  Joshua Resnick [SMTP:seraphim-at-WPI.EDU]
Sent:  Friday, April 10, 1998 2:07 PM
To:  Tesla List
Subject:  Re: Spark Gaps

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

It seems that this will be true to a point. The high voltage in the
secondary is due to resonance. However, if the spark gap continues to fire
even while there is not much voltage, and therefore current, in the tank
circuit, then not much energy is transferred to the secondary. However if
you have faster quench times, then you break the tank circuit before the
oscillations decay to a point where they are not transferring a lot of
energy to the secondary. So with a very fast RSG, you can keep the primary
oscillations from decaying to an ineffectual level. The idea that the
sudden di/dt in the primary is what is causing the higher secondary
voltages seems wrong because the voltage rise dues to resonance is many,
many times greater than the voltage rise when the spark gap initially turns on.
    /\/\ ((____)) /\/\/\/\                     Joshua Resnick
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