User`s guide

Basics Sensing System Theory - 13
Paper Sensors
Paper sensors consist of an
actuator, a U-shaped photo
interrupter, and circuitry.
Sensors are tripped as the
actuator swings against
movement of paper and
blocks the gap of the U. An
actuator can be passive
(governed by gravity) or
spring-loaded.
Note: Sensor failure can be
either mechanical or
electrical. When
troubleshooting sensors,
first confirm that the arm
Actuator
Photointerrupter
OPEN
CLOSED