Drivers - Citizen CLP-621 Technical Manual

2-2. Operation of Control Parts trol Parts

(4) Drivers

(4) Drivers
(4-1) PF motor driver (4-1) PF motor driver
This is a driving circuit to drive the PF Motor (stepping motor). This is a driving circuit to drive the PF Motor (stepping motor).
The following illustration shows a simplified circuit. The following illustration shows a simplified circuit.
The PF Motor is driven by the unipolar constant current chopper method. The PF Motor is driven by the unipolar constant current chopper method.
The exciting method for the motor is the 1st-2nd phase method. The exciting method for the motor is the 1st-2nd phase method.
The power to the PF Motor is supplied by turning ON the FET TR3. This is accomplished The power to the PF Motor is supplied by turning ON the FET TR3. This is accomplished
by activating the monostable multivibrator IC12. When IC12 is triggered, DTR3 turns ON by activating the monostable multivibrator IC12. When IC12 is triggered, DTR3 turns ON
and TR3 turns ON. and TR3 turns ON.
TEMPOFF signal is normally at "High" level and the output from IC12 can turn ON TR3 to TEMPOFF signal is normally at "High" level and the output from IC12 can turn ON TR3 to
supply +24V to the PF Motor. If the PF motor temperature rises excessively, TEMPOFF supply +24V to the PF Motor. If the PF motor temperature rises excessively, TEMPOFF
signal goes "Low" level, and the output from IC12 is inhibited. Thus,+24V to the PF Motor signal goes "Low" level, and the output from IC12 is inhibited. Thus,+24V to the PF Motor
is shut off. (For TEMPOFF signal, refer to (3-5) "PF motor temperature sensor". is shut off. (For TEMPOFF signal, refer to (3-5) "PF motor temperature sensor".
PFMA, PFMA, PFMB and PFMB signals are the exciting pulses to drive the PF Motor. PFMA, PFMA, PFMB and PFMB signals are the exciting pulses to drive the PF Motor.
The digital-to-analog converter (IC4) is used to control the PF motor current. Its output is The digital-to-analog converter (IC4) is used to control the PF motor current. Its output is
controlled by the data sent from the CPU (IC1). controlled by the data sent from the CPU (IC1).
PFCLK
From IC1 CPU
PFON
From IC11 Custom IC
GRESET
From IC1 CPU
R168
TEMPOFF
C105
Motor current control
1
From
2
IC1 CPU
3
CLP-621 & CLP-631 CLP-621 & CLP-631
Low: Turns on TR3 to supply
IC12
Monostable
Multivibrator
1
1Q 13
1A1
2
1B
3
1CLR1
SN74LV123APWR
1
4
2
IC22A
PFMA
From
PFMA
Custom IC PFMB
PFMB
IC4
D/A Converter
PFMOTCU R92
OUTA
DIN
4
SCLK
CS R94
TLV5625ID
power to the PF motor.
P182 R88
DTR3
DTC143EUA
P187
IC13
Motor Driver
7
VSA
12
VSB
P188
6
INA
P189
5
INA
17
P190
INB
P191
16
INB
PFCU
T12
R89
P197
3
REFA
14
REFB
R93
C66
SLA7024M
2-28 2-28
+24V
R86
TR3
XP132A11A1SR
8
OUT A
1
OUT A
18
OUT B
11
OUT B
[Main PCB]
CN5
1
2 PF Motor
3
M
4
5