piclist 2002\08\27\131648a >
Thread: Underwater IR Photoreflector
face BY : Jim email (remove spam text)

I had an idea that pulses caused by the brushes on the commutator could be
conditioned to digital levels and used as an encoder. Connecting a scope
to a small dc motor while running shows a pulse of 20mv whose frequency is
in proportion to the speed. It seems like capacitive coupling and amplifier
to the motor and maybe using a schmitt trigger at the amp out would be a working
alternative to opto sensors.

Hope this helps

James M

At 11:51 AM 8/26/02 -0700, you wrote:
>I'm trying to build an underwater tachometer for an AUV (autonomous
underwater vehicle) being built at the University of Victoria by a group of
engineering students.  What we hope to do is the standard shaft encoder
scheme where one determines speed by counter the number of strips that pass
by a photoreflector for a given time period.  As such, we are looking for an
IR photoreflector that is contained in a waterproof casing (maximum depth we
will be going is 30 feet).  Can anyone recommend such a photoreflector or an
alternative way to match the speed of two motors?
{Quote hidden}

http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.


See also: www.piclist.com/techref/io/irs.htm?key=ir
Reply You must be a member of the piclist mailing list (not only a www.piclist.com member) to post to the piclist. This form requires JavaScript and a browser/email client that can handle form mailto: posts.
Subject (change) Underwater IR Photoreflector

month overview.

new search...