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New Sync Gap, for comparison with 8 point series quench sync rotary
From: FutureT-at-aol-dot-com[SMTP:FutureT-at-aol-dot-com]
Sent: Friday, September 19, 1997 3:59 AM
To: tesla-at-pupman-dot-com
Subject: New Sync Gap, for comparison with 8 point series quench sync rotary
All,
I'm building a new sync rotary gap which I will compare with my
present 8 point series quenching, 120 BPS rotary sync gap. I
want to see if there will be any difference in performance using
only 2 or 4 series gaps, rather than the present 8 gaps, on my
present TC.
I happened to have a 1/4 hp induction motor which I had modified
in the past for sync operation. This is an 1800 rpm motor so it
requires 4 flats on the armature. These flats do not
have to be too wide or deep. The armature is 3 3/8" dia, and I
ground the flats 1 1/8" wide, the uncut area is 1 3/8" wide between
flats. The cuts are only about 1/16" deep, so this can be done
using hand tools for those who do not have a milling machine. I
just drilled about 17 holes into each flat to the proper depth, then
removed the remaining metal with a large hand file. It's probably
better not to grind these flats too deep, because too much power
will be lost.
The rotor is 8 1/2" dia, by 3/8" thick lexan with 4 side-type electrodes
which are made from 3/8" threaded steel stock, 2 1/8" long. Electrodes
are installed on circle 7 5/16" across centers. Motor has plenty of
power for sync-lock using this rotor.
Next I will install the stationary electrodes, and testing can begin.
BTW, the motor is mounted in a cradle which permits the motor to
be rotated to the proper phase position.
John Freau