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Old 05-02-2010, 11:29 AM
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bojan
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Join Date: Jul 2006
Location: Mt Waverley, VIC
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Quote:
Originally Posted by mbirrell View Post
The idea that I am working on works with a photo interrupter (Jatycar part no. ZD1901)
This is not going to be easy to use for encoder, you will need more than just transparent pattern printout (additional mask). And, you will need 2 of interrupter modules for each axis (to be able to determine the direction of movement).

Try this one: http://www.vishay.com/docs/84756/tcut1300.pdf
(they are used in optical mice)

Also, Steve (Kinetic) has his go on this: http://www.iceinspace.com.au/forum/s...ad.php?t=42151

My idea is around this one: http://usdigital.com/assets/general/..._datasheet.pdf

Very simple arithmetic shows that for 10,000 t/r I need a wheel (or ~100° sector for elevation) 30cm in dia, quite reasonable for any dobson mount.
And no moving parts whatsoever (apart from telescope itself)
Alternative is this one, but more complicated to use (it needs ADC's):
http://sensors-transducers.globalspe...8-D2E6D77A7724

Last edited by bojan; 05-02-2010 at 12:13 PM.
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