Re: synchronous gap (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Tue, 10 Jul 2007 18:10:05 -0700
From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: synchronous gap (fwd)

Hi Stephen,

Although I have run sync, I don't any longer. I'm not running a VFD as 
well. I would be interested in your PLL feedback details. My gap is set 
up now to vary the speed with a simple potentiometer (0 to 500 Hz, where 
the high end is way to fast to actually achieve). But it would be a nice 
addition to sync the motor as well. If you have any details on it, I 
wouldn't mind hearing what you did to accomplish the task. Maybe offline 
would be best.

Take care,
Bart

Tesla list wrote:

>---------- Forwarded message ----------
>Date: Tue, 10 Jul 2007 18:44:55 -0700
>From: Stephen A. Mathieson <sm@xxxxxxxxxx>
>To: tesla@xxxxxxxxxx
>Subject: synchronous gap
>
>I have yet to run my RSG is synchronous mode but it uses a technique you may
>find interesting.
>
> 
>
>Regular old induction motors are cheaper and easier to obtain. I am using a
>3 phase induction motor
>
>driven by a variable speed AC drive. All you have to do to make it
>synchronous is to put a PLL in the feedback loop.
>
>An added benefit is that it allows for the gap to fire at whatever point
>along the sine wave that you wish.
>
> 
>
>I have a 10 inch disk of �� G10 and I have spun it as fast as 7500 RPM with
>no problems.
>
> 
>
>The only drawback that I have found so far is that the induction motor must
>be placed outside 
>
>the magnetic field generated by the primary coil. If the motor is in the
>primary�s magnetic field the AC drive trips due to
>
>a current fault as it can no longer keep track of the current in the motor.
>
> 
>
>Good luck,
>
> 
>
>Stephen Mathieson
>
>
>
>
>
>
>  
>