AMT Datasouth Accel-7350 Service Manual page 83

C motor drive circuit
C motor uses a 4-phase stepper, and it is set in single phase by BBG020 at standby 1/2-
phase at rotation of the motor.
The current value reaching the motor is decided by turning on HCDR0–HCDR4.
Drive Method
Data control signals from the gate array consist of a speed control and phase signals. The
speed control signal is set at a certain voltage level by transistors Q8, Q9, Q10, Q12 and Q11
and resistors R58, R59, R60, R76 and R61, and is supplied to P2. This voltage level determines
how P2 controls the current, which flows to the motor.
LF motor (front) drive circuit
LF motor uses a 4-phase stepping motor, and it is set in single phase by BBG020 at standby
and double phase at rotation of the motor.
Current value, which flows to the motor, is decided by turning on LFDR0-LFDR2.
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