Feed-Motor Drive Circuit - Star Micronics TUP400 Series Technical Manual

2-3. Feed-Motor Drive Circuit

This printer employs a paper feed motor and a stepping motor. The motor rotates through a certain angle each time it
receives a pulse from the drive circuit. This printer employs a 4-phase stepping motor and controls the paper feed motor
with a phase 1-2 excitation method. The following diagram illustrates the phase 1-2 excitation method. Diagram 2-8
shows the feed-motor drive circuit.
1
2
3
4
Voltage to the motor is controlled to produced the required action, as follows.
Voltage is controlled by PA4 pin of the CPU, which goes HIGH or LOW to switch transistors DQ2 and Q2 ON and OFF.
When Q2 is ON, the paper feed motor receives VM (+24V). When Q2 is OFF, VL (+5V) is supplied to the motor via
diode D1.
ON
ON
Step
1 2 3 4
Reverse Feed
Fig. 2-8 Motor Control by Phase 1-2 Excitation
IC5
CPU
PA4
PA0
PA2
PA3
PA1
Fig. 2-9 Feed-Motor Drive Circuit
Mode
Operating
Idle
ON
5 6 7
Forward Feed
+24V +5V CN4
D1
DQ2
Q2
B
TA1
E
M-GND
Voltage Action
VM (+24V) Drives the motor
VL (+5V)
VL (+5V) Holds the motor
– 23 –
ON
ON
8
1
2
Paper Feed Motor
3
1
M
3
4
2 4
5
6