Ribbon Motor Driver - Citizen CLP-621 Technical Manual

(4-2) Ribbon motor driver

This is a driving circuit to drive the Ribbon Motor F and Ribbon Motor R (stepping motors).
The Ribbon Motor F is used to take up ribbon and the Ribbon Motor R is used to supply
ribbon.
The Ribbon Motor F/R is driven by the STEP_A/B signal sent from the CPU (IC1). The
rotational direction of the motor is determined by the DIR_A/B signal sent from the custom
IC (IC11). The strength of PF motor excitation (strong and weak) is switched by the
PDOWN signal sent from the CPU (IC1).
The motor drive circuits for the Ribbon Motor F and Ribbon Motor R are the same except
that the latter circuit has the motor rotational direction change function.
On the supply side, it is required to change the motor rotational direction depending on the
ribbon to be used, inside wound (ink-in) ribbon or outside wound (ink-out) ribbon. The
output of the Ribbon Winding Selection Switch is connected to IC702, and, by combining
this output signal with the DIR_B signal, the rotational direction of the Ribbon Motor R is
changed.
IC12B
Monostable
Multivibrator
From IC1 CPU
9
2Q 5
2A
RIBTRG
10
2B
GRESET
11
2CLR
SN74LV123APWR
IC11
Custom IC
DIR_A
95
PM0
STEP_A
96
DIR_B
PM1
STEP_B
IC1
CPU
122
D24
126
D28
123
D25
PDOWN
[Main PCB]
VMOTON
T703
CN701
CN8
8 16
VMOTON
3 11
DIR_A
DIR
STEP
4 12
STEP_A
5 13
DIR_B
6 14
STEP_B
7 15
PDOWN
PDOWN
IC702
1
7 DIR
STEP
2
PDOWN
DIR SW
[Ribbon Main PCB]
+24V
F701
R724
TR701
R725
2SJ358
DTR703
DTC143EUA
20
11
10
+3.3V
VR701
R704
R706
R709
C705
DTR701
DTC143EUA
IC706
(Same as above circuit)
R733
2-29
2-2. Operation of Control Parts
IC701
CN702
Motor Driver
3
16
VBB1 OUT1A
5
4
21
VBB2
OUT1B
DIR
2
9
OUT2A
STEP
1
4
OUT2B
1
REF
CN703
3
4
2
1
Ribbon Winding
CN706
Selection Switch
4 Inside Wound
5
Outside Wound
[DIR SW PCB]
CLP-621 & CLP-631
Ribbon Motor F
(Take-up Side)
M
Ribbon Motor R
(Supply Side)
M