Shaft Encoders

[Peter Ullrich]

At 10:33 24.04.1997 +1000, Ken Stone wrote:
>>Im trying to figger out how that would be done with available components
>>w/o using servo encoders.. but those WOULD be really nifty if implemented
>
>Has anyone ever considered the usee of surplus stepper motors (ex flopp or 
>hard drive) as shaft encoders?  Certain models (the more common ones) appear 
>to use two 90 degree out of phase windings. With the signals generated in 
>these coils correctly processed, you would have an output quite similar to
>that of a shaft encoder, and for a fraction of the price, especially if,
>like me, you have dozens of them lying around. I have played around briefly
>with interfacing these things... enough to know it should be possible.

A German Electronics magazine didi this (I think it was in ELRAD). They had
to amplify the pulses and that´s it.

>The other great shaft encoder to adapt is the arcade video game track ball!

I prefer the cheap shaft encoder from Bourns:

There is an Absolute encoder with 128 steps per revolution and a relative
version with a simple 90 degree gray code.

Look at:

http://www.bourns.com/cat/ace.htm
http://www.bourns.com/frames/ACE.htm

Ciao
Peter




        \|/
       (o o)
--oOOO--(_)--OOOo------------------------------------------------------
                   Ing. Peter Ullrich        mailto: ullrich at kapsch.net
                   http://www.geocities.com/SiliconValley/Heights/3586/
                   Hardware & Software Developer /  Electronic Musician
   .oooO           KAPSCH AG / SGB2                    Vienna / Austria
   (   )   Oooo.            Traffic Control and Transmission Technology
----\ (----(   )-------------------------------------------------------
     \_)    ) /
           (_/