Service manual
Principles of Operation
Carriage motor specifications
Drive Voltage
Coil Resistance
Current
4-phase, 48pole stepper motor
24 V
f
10%
21 ohms
f
7% at 77O F
(25’
C)
0.34 A, maximum (rush current)
Driving:
0.3 A, typical (triple speed, 24
VI
0.23 A, typical (double speed, 1.5 speed,
normal speed, 24
VI
Holding:
0.17 A
f
20%
Carriage motor drive circuit block diagram
Figure 2-30 is a block diagram of the carriage motor drive circuit. The CPU does
not directly execute phase switching for the carriage motor. Instead, gate array
6C generates the phase switching based on CPU-generated pulses. The
STK-6981B circuit stabilizes the drive current.
Figure 2-30.
Carriage Motor Drive Circuit Block Diagram
LQ-200/AP3000
2-31