B. Solenoid drive circuit
[a] Paper feed solenoid (DFSOL), reverse solenoid (DRSOL) drive circuit (DRSOL --- SF-A57 only)
This circuit drives the weight plate which presses the bundle of originals on the tray, the paper feed solenoid which drives the paper feed section
shutter, and the reverse solenoid which drives the reverse guide to lead an original to the reverse path when reversing. The basic composition is the
same. The drive signal (ON at HIGH) from the gate array is inputted to the gate of FET (Q14, Q15).
The ON duty of the drive signal can be varied from 0 to 100% (255 steps). The frequency, however, is 20kHz.
C. Fan motor drive circuit
The fan motor is provided with the lock detection function to cool the power source and the control PWB.
When a HIGH level is outputted from the gate array (IC7-20pin), the transistor (Q16) conducts to drive the fan motor. At that time, the lock detection
signal is outputted from the fan motor. In normal operations, a LOW level is outputted and transmitted to the gate array (IC7-58pin).
In case of abnormal operation, a HIGH level is outputted.
DF1B-9P-2^5DSA
TP36
R82
1.0K
DFSOL
TP28
R88
1.0K
DRSOL
DRSOL CN8-5
+24V
CN8-4
PGND
Q14
2SK1726
+24V
D8
SS14
173981-7
15
14
G/A
(IC7)
PWM2
PWM1
Reverse
solenoid
Paper feed
solenoid
Solenoid drive circuit
DFSOL CN5-3
+24V
CN5-4
PGND
Q15
2SK1282-Z
FD+24V
D7
SS14
R16
10K
TP48
R88
1.0K
DRSOL CN8-8
+24V
CN8-7
PGND
Q16
RN1427
DC+24V
D10
173981-8
20
58
G/A
(IC7)
PWM7
P5
GND
CRG10G103J
C27
GRM40B103K50PT
0.010µ
R17
10K
+5V
CRG10G103J
R15
4.7K
CRG10G472J
FANARM
CN8-6
173981-8
CFM
SIG
C
E
B
A
K
Fan motor
Fan motor drive circuit
– 34 –
Содержание SF-A18
Страница 42: ...CONTROL PWB SF A18 41 LED PWB SENSOR PWB ...
Страница 46: ...CONTROL PWB SF A57 LED PWB SENSOR PWB 45 ...