Driver Pcb; Paper Feed Motor Drive Circuit; Solenoid (Pick-Up,Clutch), Erase Lamp, Fan Motor Drive Circuit - Brother HL-600 Service Manual

1.4

Driver PCB

1.4.1

Paper Feed Motor Drive Circuit

The motor driver is a four-device FET array, which manage the constant current control
by feeding back the voltage of the current detection resistor. The comparator for the
constant current control is incorporated in the AS IC on the main PCB, which controls the
excited output to go OFF by the specified period (12.5µs) when the motor drive current
exceeds the specified current level. The excitation method is 2-2 phase excitation with
an unipolar drive.
The four diodes D1NL2OU and Zener diode are the circuit that protects against
overvoltage due to counter-electromotive force.
R11
R12
100K
100K
0V
1.4.2 Solenoid (Pick-up, Clutch), Erase Lamp, Fan Motor Drive Circuit
A darlington transistor (2SC5060) is used for these circuit.
A flywheel diode D1NL20U is provided for the fan motor drive circuit to prevent
counter-electromotive force.
UPA1572H
47
R8
47
R7
R6 47
R9 47
R10 R13
100K 100K
R4 R2
1.2 1W
1.2 1W
+24VRET
Fig. 2.14
R14
3.3K
R15
3.3K
R16
3.3K
R17
3.3K
#1
3
2
5
4
D1NL20U
1
7
D1
6
9
9
10
P9 PICKUP
+24VI
6
5
4
3
2
1
P10 ERASE
1
2
2SC5060
Q4
2SC5060
Q43
2SC5060
P4 FAN
Q2
1
+24V
2
2SC5060
Q1
D1NL20U
DS
+24VRET
Fig. 2.15
II - 11
+24VI
ZD1
RD30FB3
+24V RET
D1NL20U D1NL20U D1NL20U
D2 D3 D4
CLUTCH
RESIST
+24V
CLUTCH
PICKUP
+5V
RESIST
GND
+24V
ERASE
+24V
FAN
C1
50V 100U
P3 FEED MOTER
1
PMA
2
COMA
3
PMAB
4
PMB
5
COMB
6
PMBB