Re: Synchronous Motor for SRSG

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

Original poster: "Dr. Resonance by way of Terry Fritz <teslalist-at-qwest-dot-net>" <resonance-at-jvlnet-dot-com>


There is another way to set your sync on a synchro motor that's faster and
works just as good as checking it with a strobe light each time you fire up
the coil.

First, test the synchro and tune your coil to full output spark.

Next, set your variac to around 30-35% and note the spark output from the
sec. coil.  This serves as a reference point.  Also, this time only, check
the sync with your strobe.  Also, check the output spark at 30% variac with
the motor out of sync.

Whenever you turn your coil on, run the variac up to this 30% reference
point.  If the synchro motor is out of sync the spark will be considerably
less.  It's easy to see the difference in the length of the spark output.

Just switch the synchro motor off for 4-5 sec. and then switch it back on
with the coil running at the ref point.

When the motor is in sync you will immediately now the difference due to the
spark length at the 30% reference point.  Usually you only have to hit the
switch 1 or 2 times and you will be in sync.

This eliminates testing the rotor each time you run the coil.  It's easy to
tell if it's in sync from the output spark.  No need to monkey around with a
flourescent or strobe light each time if you know your coil's
characteristics at a lower ref. point.

We do it this way and it always syncs in 1-3 hits of the RSG switch.  Then
run the variac up to full power and enjoy.

This also allows you to use the much less expensive non-salient pole
hysteresis motors and get the same benefits as you would from the more
expensive salient pole types.  You just note the output spark length at the
lower output 30% point.

If any experimenters need the hysteresis sync 1800 RPM motors we still have
dozens of them in stock.

Dr. Resonance

Syncing in Wisconsin