Printer Mechanism Driver Circuits
Print head driver circuit
The head driver signal is output from CPU (U5) pins 64 to 72. Receiving this drive signal,
transistor array QM1 and QM2 and transistor array QM3 turn On, Off, and drive the head.
Power supply time to the head is adjusted by the supplied power voltage. The CPU (U5)
changes the power voltage between analog and digital at AN0 (pin 7) and decides and controls
the head power supply time according to the internal time table.
To prevent damage to the head during excessive printing, a heat sensor has been installed in the
print head. An analog-digital conversion of the partial pressure difference between the heat
sensor and R18 is carried out in AN1 (pin 8) of the CPU (U5) and the temperature is calculated. If
the head is overheating or working improperly, the ERROR LED flashes.
Figure 2-25 Print head driver circuit
COM (# 3.5.7 )
# 5
# 7
# 1
# 3
Print head unit
HEAD1
HEAD5
HEAD6
HEAD2
RM3
8
7
6
5
4
3
2
1
Q4
9
7
5
3
8
6
4
2
1
1
0
QM1
Q6
Q5
Q7
+5V
RM4
8
7
6
5
4
3
2
1
Q8
9
7
5
3
8
6
4
2
1
1
0
QM2
Q10
Q9
Q11
HEAD3
HEAD7
HEAD9
HEAD8
+24A
D7
68
69
65
72
Q12
R20
1
2
3
CN7
4
5
6
7
8
9
10
11
12
13
14
15
P44
P45
P41
P50
HEAD4
67
66
70
P43
P42
P46
71
P47
64
P40
8 HD TEMP
P61/AN1
7 V DTC
P60/ANO
6
AVSS
5
AVCC
C30
C31
R45
R46
R18
C19
C29
R8
+
C33
_
R19
+24DT
# 9
C0M ( # 1.2.9 )
THEM1
THEM2
# 4
# 6
# 8
COM (# 4.6.8 )
# 2
FG
D27
D28
Q13
U5
+5V
+5V
D50
D32
D38
D39
D40
D41
D42
D43
D45
D44
— 50 —
Summary of Contents for UP-250
Page 1: ...EXTERNAL PRINTER FEB 2000 MODEL UP 250 without price TECHNICAL MANUAL ...
Page 95: ... 86 END END Yes No Action 4 Replace main PCB Replace printer OK Action 4 mechanism assembly ...
Page 136: ... 127 ...
Page 149: ... 140 Main Circuit Board Parts Layout ...
Page 150: ... 141 RS 232 Serial Interface Circuit Board Parts Layout ...
Page 151: ... 142 IEEE 1284 Parallel Interface Circuit Board Parts Layout ...
Page 152: ...RS 485 Serial Interface Circuit Board Parts Layout 143 ...
Page 160: ... 151 Case Unit Lubrication Points Diagram 4 G 31 4 G 31 3 G 31 3 G 31 ...
Page 163: ... 154 EXPLODED DIAGRAM FOR TM U200B U210B NO 1 ...
Page 164: ... 155 EXPLODED DIAGRAM FOR TM U200B U200PB U210B U210PB NO 2 ...