Subject: Re: steppermotor as encoder -> presto, moterized pot.
References: <firstname.lastname@example.org> <email@example.com> <3DA3B2F4.F6F7D0BC@webaccess.net>
Organization: The Armory
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From: firstname.lastname@example.org (Richard Steven Walz)
Date: 09 Oct 2002 05:38:05 GMT
In article <3DA3B2F4.F6F7D0BC@webaccess.net>,
Chuck Simmons wrote:
>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
>> >Selsyn waveform to drive one as an out device, OR you can sense the
>> >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 ones I have doc on are the ones used on battleships, they use an
amplifier from tiny ones to great big ones.