From: Chuck Simmons
Organization: You jest.
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Subject: Re: steppermotor as encoder -> presto, moterized pot.
References: <firstname.lastname@example.org> <email@example.com> <firstname.lastname@example.org> <email@example.com>
Date: Wed, 09 Oct 2002 04:39:38 GMT
NNTP-Posting-Date: Tue, 08 Oct 2002 21:39:38 PDT
Richard Steven Walz wrote:
> In article ,
> Tony (remove \"_\" from email address) wrote:
> >For all the desirable attributes of Selsyns, then don't really address the issue
> >here- the OP wanted to use the knob as both input and output. You can simulate a
> >Selsyn waveform to drive one as an out device, OR you can sense the waveform and
> >use it as an input device, but to do both you need to do something similar to
> >what I suggested for the stepper solution (and even if you can still get
> >Selsyns, old floppy drive motors are still lots easier to get).
> That's true, selsyns are one way, I recalled after I reviewed my notes.
> It may be possible to sense feedback on each coil and arbitrate it into
> rotation data, however.
No. If you connect them together and apply power, when you turn one the
other turns the same. The motion of one will be repeated at the other.
Thus you can sense the windings to determine position or you can drive
to a position. The torque, even from large selsyns is not great. If I
remember correctly, they work as followers with three phase power on the
stators or single phase on the rotors.
... The times have been,
That, when the brains were out,
the man would die. ... Macbeth
Chuck Simmons firstname.lastname@example.org