[chbot] Shaft encoder product

[Mark Atherton]

Just taken delivery of a CUI AMT103-V : an interesting take on the 
age-old problem of rotational position detection.

Traditional solutions include attaching a disk with multiple lines per 
rotations , then using a light source and a pair of offset detectors 
which can resolve rotational velocity as well as direction.

Another solution is the 'resolver' which is a rotary transformer, and 
some clever gubbins, where the primary is excited at a few 10s of kHz, 
and the 90 degree secondaries resolve position by rectification and 
comparative amplitude (among other techniques).

The CUI part is a capacitive sensor, and is supplied with required tools 
and a variety of plastic collets which can be attached to shafts of 
various diameters. Google US6892590 for the associated patent.

There are some clever buggers out there...

-Mark