Re: Double Throw Spark Gap (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sun, 14 Oct 2007 14:46:35 EDT
From: FutureT@xxxxxxx
To: tesla@xxxxxxxxxx
Subject: Re: Double Throw Spark Gap (fwd)

 
In a message dated 10/14/2007 1:41:19 P.M. US Eastern Standard Time,  
tesla@xxxxxxxxxx writes:
 
Bart,
 
I didn't mention it, but I also used series static gaps in series with  the 
two types
of rotaries, to help the quench.
 
John


I  mentioned in this thread somewhere how different the main gap is from 
a  normal RSG. Normally, we set electrodes close and let timing control 
the  bangs. Here, that may not be the best thing to do as it might start  
conduction earlier than wanted. However, the static gap on the front end  
will not only help the quench but will also allow a narrow gap width on  
the main gap (ensuring timing between charge and main gap firing is  
separated as desired) and allow voltage control in the main gap. This  
gap will be controlled by both timing and voltage.

Take  care,
Bart

Tesla list wrote:
> ---------- Forwarded message  ----------
> Date: Sun, 14 Oct 2007 10:23:36 EDT
> From:  FutureT@xxxxxxx
> To: tesla@xxxxxxxxxx
> Subject: Re: Double Throw  Spark Gap (fwd)
>
> This burst TC operation seems similar to a  project I built in the  past 
which
> I called a DC Disruptive  Compound Storage Staccato Tesla Coil.   This
> project is  written up in the Oct 1996 TCBA Newletter (Volume 15,  #4).
> The  project is also shown on my VHS video tapes # 16, 17, and  18.  
>  
> This system stored energy in a DC filter  capacitor.  This energy  in
> turn was fed through a large  choke to a rotary switching spark  gap.
> This gap rotated at a  slow rate, and was in series with the normal
> fast turning rotary gap  in the tank circuit.  The tank cap also  stored
> energy of  course.
>  
> The sparks from the toroid emitted in bursts at  the rate of about
> 3 per second and was noticeably pulsed from a visual  and aural
> point of view.  Each burst consisted of about 24  bangs.  The  sparks
> were about 56" long.  Input power  was about 460 watts.
>  
> The sparks seemed to appear extra  bright probably because of how
> the human eye reacts to such pulsed  spark streamers.
>  
> The rotary switch was made from a  sheave pulley from which arc
> sections were cut away.  This gave  the correct amount of  "on-time"
> vs. "off-time".  This  pulley was driven at a rate of 1/6th rps.   I tried
> running  the switch faster, but this made the sparks dimmer.  The
> timing  was such that 48 bangs should have occurred  during each   burst,
> but the voltage dropped below the spark gap firing threshold,  so only
> about 24 bangs actually occurred during each burst.   
>  
> For best results there should be a proper balance  among; input  current
> limiting, filter cap value, output choke  inductance, "on/off" times and  
> ratio,
> and break-rate of  the standard rotary gap.
>  
> Observe suitable safety  precautions since this is a DC coil.  
>  
>  John







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