Re: John Freau's SRSG Phase Controller

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 12/19/00 7:13:15 PM Eastern Standard Time, 
tesla-at-pupman-dot-com writes:

> 
>  It is very possible the circuit works just fine as is.  The computer model
>  is just a guess without any testing to see if it is correct.  Maybe tonight
>  I will get a chance to hook some stuff up and see if the model is real or
>  just a bunch of balony.  These models always have to be tested to be sure
>  they are correct and I would not be surprised at all if this is one case
>  were it is far off.  Only true measurements and testing will tell.  I am
>  also using 1/4 HP motors which may or may not make a difference.  I took
>  some scope measurements of just the motors the other day:
>  
>  http://hot-streamer-dot-com/TeslaCoils/Misc/SRSG-VI.gif
>  
>  Cheers,
>  
>   Terry

Terry,

I reported my results and voltages before, so you and others can 
compare with your own systems and tests.
Yes, the motor may make a difference.  I'm glad you thought about
the resonance issue and the fuse safety mod.  We do have to be
careful with this stuff.  I tested the fuse idea on my system and it
worked great!  In normal operation with the phase shifter, the fuse
never blew.  But when I disconnected the motor, the (2.5A) fuse
blew quickly when I applied only 30 volts of line voltage.  2A is
most likely a better rating as you suggested.  That resonance does
get scary    :)  so I didn't do a full power test with no motor in place.

I tried adding a 150 ohm resistor across the motor, but this makes
the motor lose lock about halfway though the variac range.  My
variac has just 160mH total BTW.  (It's a 7.5A powerstat model).
I didn't explore what happens to the fuse if the motor loses lock.
I'm still using 50uF for the cap.

I'm sure the technique will improve and evolve as you and others do 
hands-on tests with other motors, components, etc.

John Freau