Re: larger than resonant (fwd)

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Original poster: List moderator <mod1@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Fri, 01 Jun 2007 19:20:25 -0700
From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: larger than resonant (fwd)

Hi Scott,

Smaller transformers like NST's will almost always run LTR. Larger 
transformers like PT's and PIG's will often run STR. Gary mentioned bang 
size. This is a big deal for both NST sized transformers and large pigs. 
If you were to run STR with an NST, the cap would be small and the bang 
energy would also be small. Your better off from a spark length 
standpoint to run LTR with one of these smaller transformers. The reason 
has to do with a transformers ability to charge the cap which is based 
on the cap value and the current available from the transformer. That is 
the reason why we only go "so far" with LTR sizes. Thus, each 
transformer rating has it's own LTR value.

Larger transformers like pigs, if run LTR, would have an incredible bang 
energy that could be devastating (and expensive). There is some limit to 
transformed energy for every coil before the coil turns into a blaze of 
glory, but one we almost have to blow it up before we actually find that 
limit. In most cases, large transformers are better off running STR to 
keep the bang energy within a coils abilities.

In both cases, the spark gap, when running without a failure, will limit 
the breakdown voltage. If a static gap, it's a constant limit that 
usually decreases with time due to heat buildup, but for a rotary gap, 
the timing of electrode alignment and the current available to charge 
the cap is the limit for voltage. It is possible to run very high bps, 
but the balance between current and capacitance must be met. If either 
is not designed well for the bps ran, sparks can diminish, but if done 
right, spark lengths can be very good. I personally like a 300 to 340 
bps myself when I run my variable rsg. If I were to change capacitance 
or transformer for the same coil, there would be a different bps range 
where the coil runs best.

Take care,
Bart



Tesla list wrote:

>Original poster: List moderator <mod1@xxxxxxxxxx>
>
>
>
>---------- Forwarded message ----------
>Date: Fri, 01 Jun 2007 05:54:39 -0400
>From: Scott Bogard <teslas-intern@xxxxxxxxxxx>
>To: tesla@xxxxxxxxxx
>Subject: larger than resonant
>
>Hey everybody,
>     Can somebody explain to me the advantage to using a "resonant" or 
>"larger than resonant" tank capacitance?  I seen coils get huge sparks using 
>LTR and also very small tank capacitors, so what is the point?  Thanks.
>Scott Bogard.
>
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