Epson LQ-860 Technical Manual page 105

2.3.6 CR Motor Control and Drive Circuit
Figure 2-55 shows the CR motor controlldrive circuit block diagram.
The CR motor is controlled by the CPU (46). Phase switching signals are output from the CPU ports (POO
to P03) which have the real time output function.
The phase switching signal output from the CF)U is sent to the constant current drive IC (1A). In order to drive
the carriage motor at constant speed, the IC inputs the reference voltage which corresponds to the motor
speed. The reference voltage is controlled by the CPU via the gate array IC (lIB) for extended ports.
I
CR
MOTOR
A
Figure 2-55. CR Motor Control/Drive
+35
~ - J - - - - l I
1A
CR MOTOR
DRIVER (1A)
ID
SURGE
VOLTAGE
4
'
CIRCUIT II
'P
2-58
1 - - - - - - - - - - -
BUFFER (16)
PHASE
PULSES
Circuit Block Diagram
CPU
(4B)
' ...,..