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Old 14-01-2013, 07:45 AM
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bojan
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Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 7,112
Quote:
Originally Posted by danstar10 View Post
.. If I wanted to use the 1rpm motor you linked from ebay what would I need to attach to it to drive it? Just a battery or would it need circuitry?
Thanks
You will need only transformer, and mains power - those timing asynchronous motors (with internal gearbox) are designed to operate at AC voltage only.
Just make sure they are designed for 50Hz - those for US market will turn slower at 50Hz (they are deigned for 60Hz mains, so in UK they will be turning with 0.8333 rpm).


The circuits you mentioned require external PC to operate.

This is the reason I suggested to you to use "non-standard" arm length for your barn-door, and available electronics, with no fuss.
Economy driver may be OK for wide field photography, provided the frequency is properly adjusted. This can be achieved by fixing a small telescope (with maximum available power) on the mount, and adjusting the pot until the star field in the eyepiece is steady over longer period of time.
Then you can try it with camera and (short focal length) lens.

For the totally independent, battery operated, processor controlled barn-door (or eq) mount, have a look here.
I build this with very old processor (motorola 705, because I have a few leftovers from previous projects) and this works a treat - I still use it for wide fields.
But, it requires some experience with electronics and mechanics...

There were other discussions here on this topic.. for example this one:
http://www.iceinspace.com.au/forum/s...ht=PIC+stepper

Last edited by bojan; 14-01-2013 at 08:31 AM.
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