From: Chuck Simmons
Organization: You jest.
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Subject: Re: 3 wire stepper motors
References: <email@example.com> <1033132989.893377@savina>
Date: Mon, 30 Sep 2002 04:55:56 GMT
NNTP-Posting-Date: Sun, 29 Sep 2002 21:55:56 PDT
> Sounds like those are synchronous motors you are looking at, not stepping
> motors. Superior makes both.
> Tell us the model number, should be on the end of the motor. If so they
> have a set speed, typically 72 RPM when running.
As it happens, all permanent magnet stepper motors and brushless DC
motors are technically synchronous AC motors. I call attention to
"Brushless Permanent-Magnet Motor Design" by Hanselman, 1994, McGraw
Hill. The motors are magnetically the same. The internal structure of
the Superior Electric 72 RPM synchronous motor is identical to that of
the Superior Electric 200 steps per turn DC stepper motor. Take them
both apart and have a look. There is no difference except in the
windings and that is trivial (the steppers have either 4 or 6 wires
while the synchronous motor has three). Note that because a quarter of a
cycle of AC is one step for a stepper, a 200 step per turn motor running
on 60Hz AC power will rotate at 72 RPM.
... The times have been,
That, when the brains were out,
the man would die. ... Macbeth
Chuck Simmons firstname.lastname@example.org