Zerorest Sensor Services
In the late
eighties I was asked to develop speed sensing for LSHT
(low speed high torque) gerotor motors on salt and sand
spreaders used for snow and ice control. The sensors are
for the motor driving the chain/belt in the bottom of a
vee bottom truck or for the motor on an auger across the
tailgate. These drives feed the medium onto a slinger disc
driven by a motor with a sensor. A controller
matches the speed of the drive motors to the ground speed
of the vehicle to control the media spread per lane mile.
Most sensors in use were
analog. They have the disadvantage of not providing a
signal at very low speed. No signal was produced at low
speed when accelerating from a stop, a difficulty in
intersections. I decided to seek out a digital or pulsed
signal. My research led me to a hall effect sensor and
motor with magnetic poles around the circumference.
Sensors were typically on the ends
of augers and exposed to physical damage and excess
corrosion. The LSHT motors had the advantage of having the
sensor mounting clamped between the motor and the driven
device offering a compact protected location..
Thousand of these motors have
been used in the field successfully. My goals are to
improve upon this success with improvements in
reliability, ease of assembly, fit, mounting options, and
in the number of pulses produced. New sensor technologies
for old or new uses are also available.