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Re: 180 BPS synch? (fwd)

---------- Forwarded message ----------
Date: Tue, 17 Jul 2007 19:34:58 -0700
From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: 180 BPS synch? (fwd)

Hi Phil,

No, the modeling does not. I expect others have noticed similar optimum 
bps rates when running in this mode and I expect they found their 
optimum in the 300's somewhere (if they used a variable speed drive of 
some type). This is not a synchronous motor and that should be inserted 
here. This is simply an arsg using a VFD to control the speeds, 
direction, torque, etc.

I have noticed that if I begin going too fast, the spark lengths 
decrease rapidly. It doesn't take much more. It also runs more 
erratically at lower speeds but the spark lengths are still pretty good. 
There is simply a speed at which the sparks are good and the spark 
operation is "really" smooth. It's at that point where you can't hear 
the spark gap at all and all you hear are the sparks themselves. When 
running srsg, I could run good, but I was still stuck in one domain or 
another. By varying the bps to whatever I wanted, with the help of a VFD 
maintaining a constant speed at whatever I set it to, I could find the 
best possible bps, at least for this coil and gap setup. I'm sure others 
would have better performance at other bps ranges and I'm sure it's 
based on gap efficiency and coil parameters.

I determined the bps not through measuring, but by calculating the bps 
based on the speed of the VFD reading. So, the number is based on a back 
calculation. If there were a great number of misfirings, I would be off 
by whatever margin. So, as I am big into measurements, I want to make 
sure that is clear.

Take care,

>    Very interesting! Does the modeling explain this in  any way? Have you 
>noticed any tuning that significantly affects this sweet  spot?
>    I may have to try a variable-speed setup with my  pig coil when I get it