Need help with device type....

Heya,
I have the need for a device which has the following requirements and was wondering if someone could tell me what the device is called:
-- It measures the angle at which an axis is rotated -- It knows the angle it is at, even if it has been moved while off
In my head I'm picturing an axle which has one wire per degree around the axis. As the axle rotates, it makes a connection with the wire at a particular degree which is how it knows its location on the axis.
Any help anyone could give me would be great.
-K
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That would be an Absolute Rotary Encoder
Try www.stegmann.com

Here you might be thinking of a drum sequencer - commonly used on old-style washing machines and occasionally seen around modern factories..
HTH, Cameron:-)
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You may also want to consider using a resolver, or if you can stand the maintenance, a good-ol' potentiometer. Each type has it's advantages, so if your application is really demanding you may have to choose carefully.
-------------------------------------- Tim Wescott Wescott Design Services http://www.wescottdesign.com

old-style
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You can use an optical encoder: http://www.opticalencoder.com/applications.html
READ = http://www.opticalencoder.com/pdf/INTRODUCTION.PDF
Absolute best, but "A Quad B" is OK as long as it passes it's home position one time at startup and control system not turned OFF. These are good below for around $ 100, I get 1/4 th degree resolution using them tied into HS counter inputs on a <$300 GE micro PLC ( 360 line unit ).
http://www.opticalencoder.com/pdf/CP300%20size%2015%20encoder.PDF
http://www.opticalencoder.com/pdf/Modular%20encoders.PDF
SMALL POT LIKE http://www.cole-switches.com/pdfs/encoder.pdf
HP makes some relatively cheap OEM ones, get a sample. Also try DigiKey.
http://dkc3.digikey.com/PDF/T041/0997.pdf
It all depends on what you need to interface to, both ends.

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