RE: SRSG phase controller

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

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jduva-at-baytechnologies-dot-net>

  I've done something like that with my phase controller.  I have two
switches, though.  One switch (dimmer) spins up the motor smoothly.  That
dimmer is plugged into the phase control box, which houses an AC volt meter,
a surface mount fuse, and a toggle switch.  The control box is bolted
directly onto a small variac and the cap bank hugs the side of the variac.
The control box gets plugged into the 120V power source, the motor gets spun
up using the dimmer, then the toggle switch is thrown to connect the fuse,
cap bank, and variac to the circuit.
  When everything gets shut down, the phase control circuit is removed via
the toggle switch before the motor power gets cut.  If I forget to switch
off the control circuit, I get a mild self-braking from the 1/6 HP motor
which usually blows my fuse in the control box or trips the protective
circuitry in my motor.
I don't have schematics with me, but I remember that I used John Freau's
design for the phase control circuit and just added the toggle switch before
the fuse and caps.

Hope that helps in some way!
-Joe

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, April 18, 2001 8:10 AM
To: tesla-at-pupman-dot-com
Subject: SRSG phase controller


Original poster: "Steve White by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<slwhite-at-zeus.ia-dot-net>

I have been following the posts concerning the design of SRSG phase
controllers. One of the major concerns, at least for larger motors, appears
to
be the self-breaking action of the motor upon spin down. Could this not be
prevented through the use of a double-pole switch to completely remove the
phase control circuitry from the motor when it is turned off? One of the
switch
poles would break the circuit from the 120 volt power while the other switch
pole would simultaneously break the circuit from the phase controller to the
motor. This would prevent any self-breaking action. Comments?