Pg (Platen Gap) Motor Driver Circuit - Epson DLQ-3000 Service Manual

DLQ-3000+

2.3.9 PG (Platen Gap) Motor Driver Circuit

Since a PM-type stepping motor is used for the PG motor, the motor can
rotate in the both forward and backward direction and stop anywhere. The torque from the
PG motor moves the CR guide shaft to obtain the proper PG. (Refer to Section 2.1.3.) The
motor is driven by 2-2 phase. Signals for 4 phases (PGA, PGAN, PGB and PGBN) are
output from the gate array E05B46 via the transistor array SDC03-V1. To hold the motor,
the hold signal (PGI) is output from the same gate array. Then the transistors 2SC3859
(Q4) and SHA03-V1 (Q3) are turned off to change the drive voltage from PBS (+35V) to the
5 VDC. See Table 2-18 for PG motor specification.
Motor type
Power supply voltage
Coil resistance
Consumption current
(per 1 phase)
Drive frequency
Drive mode
Excitation mode
Rotational direction
Figure 2-21. PG Motor Drive Circuit Block Diagram
2-28
Table 2-18. PG Motor Specification
4 phases/8-pole/PM-type stepping motor
35 VDC 6%
250 18
Rush: 0.2 A on the average
Hold: 0.02A
350 pps
Constant current uni-polar drive
Uni-polar constant voltage drive, 2-2 phase drive
CW: Widens the PG
CCW: Narrows the PG
Rev. A