Specifications

8.7 BELT DRIVE MOTOR CIRCUIT
A dc servomotor is used as the belt drive motor. The driver IC controls the
speed of the belt drive motor. The CPU sends the speed data (programmed)
to the driver IC. The driver IC sends the pulse-width-modulation (PWM)
signal to the driver circuit, which sends the motor drive pulses.
An encoder in the servomotor has two magnetic sensors that generate two
pulse signals (phase A and B). The driver IC monitors the belt speed and
direction by these pulse signals and uses this data to regulate the motor’s
speed.
Speed
Driver
Driver
CN103-1
PWM
ON/OFF
DF Main Board (PCB 1)
Circuit
CPU
IC
Data
Phase A
Phase B
+5V
CN103-2
CN103-3
CN103-4
CN102-1
CN102-2
Forward/
Reverse
Encoder
Belt Drive
Motor
1 December 1990
8-18