🚀 go-pugleaf

re: Vince Pugliese's inquiry on deriving velocity info from quadrature
shaft encoders...SGS (and other semiconductor vendors) make a part
called the L290 which takes two channels of shaft encoder input and
produces a bipolar analog voltage whose amplitude is proportional to
shaft speed and polarity to direction of rotation. This part was designed
as part of a three chip set for small servomotor applications. The one draw-
back is that it requires a shaft encoder which produces pseudo-sinusiodal
output pulses of approx. +- 0.5v instead of the normal 0 to +5 TTL square
wave pulses provided by garden variety encoders. Such analog output encoders
are readily available, however, from a number of manufacturers including
Sensor Technology, Sharp and others. The original application for this chip
set was for servo control of daisy-wheel print heads. I have often encountered
these type encoders in surplus stores.
Bruce Koball
Motion West
2210 Sixth Street
Berkeley, CA 94710
415-540-7503
bkoball@cup.portal.com