Re: V11.1 for JAVATC (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sun, 02 Sep 2007 02:27:27 -0700
From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: V11.1 for JAVATC (fwd)

Hi Matt,

Hopefully you saw my correction regarding LTR values and bps, but this 
does not affect the question you asked. I never said "efficient", I said 
there's little difference between 120 and 240 bps regarding sparklength. 
In the sense of how you asked the question, I assume you believe 240 bps 
would be inefficient? It's not "inefficient" and yes it does fire at 240 
bps (as long as your cap charge and presentation is set correctly; the 
same is true for 120 bps operation).

But to your statement about "zero volts at every other presentation"; 
this would only be true if you forced the firing position at peak and 
zero crossing (which you would find doesn't work very well for 120 or 
240 bps). SRSG's at 120 bps will be positioned to fire along the 60Hz 
cycle after peak by some amount. The same is true for 240 bps. Your 
never firing at zero crossing. When running 240 bps, you'll find it to 
run best right about when the voltage crosses the current (which is 90 
deg out of phase). In practice for 240 bps, the presentations are set to 
fire between 20 and 45 degrees after and before voltage peak. Something 
worthy of noting is the VI product at these points (this is when it is 
highest).

Here's a chart Jeff sent to the list many years ago regarding srsg 
timing. Note the blue triangles which will help visualize the situation. 
It shows 120, 240, and 480 bps.

http://www.classictesla.com/temp/kva_srsg_timing_chart.gif

Take care,
Bart

PS: There really is little difference between 120 and 240 bps operation. 
120 bps might get you an inch more on say a 35" streamer. Of course, 
just like every other aspect of coiling, if your cap is too big for 240 
bps (or NST too small), then don't expect to get your moneys worth. As a 
matter of fact, if a coiler were to use the same cap size and the same 
NST comparing to say 120 bps, any bps higher than 120 would be less 
efficient right off the bat. That is not an accurate comparison (apples 
and oranges). The cap charge is what "must" be equal for a comparison. 
In otherwords, you fire at the same charged voltage but at the higher 
bps. Easier said than done.

Tesla list wrote:

>---------- Forwarded message ----------
>Date: Sat, 1 Sep 2007 19:47:44 EDT
>From: Mddeming@xxxxxxx
>To: tesla@xxxxxxxxxx
>Subject: Re: V11.1 for JAVATC (fwd)
>
> 
>In a message dated 9/1/07 3:37:39 P.M. Eastern Daylight Time,  
>tesla@xxxxxxxxxx writes:
>
>Besides,  for a SRSG at 240 bps with a .05uF cap, well, 
>that is just a nice  configuration. And further to that, as D.C. had 
>suggested around 0.04uF,  that is doable as well. It's still LTR, just a 
>little less. So 240 bps at  .02uF (see how the cost comes down?).
>
>Take  care,
>Bart
>
>
>
>Hi Bart,
> 
>    It seems to me that a SRSG at 240 BPS on a 60 HZ  line would have near 
>zero volts at every other presentation. How is this  efficient?
> 
>Matt D.
>
>
>
>************************************** Get a sneak peek of the all-new AOL at 
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