AL-1622 (serv.man16). Electrical section - Sharp Copying Equipment Service Manual (repair manual). Page 14

AL-1611/AL-1622

ELECTRICAL SECTION

13 – 14

This circuit detects ON/OFF of power to control start/stop of each circuit. The 5V voltage and WTOVF signal of the main PWB is detected by the reset

IC to generate the reset signal.

When the power voltage reaches the specified level, the circuit operations are started. Before the power voltage falls below the specified level, the cir-
cuit operations are stopped to prevent against malfunctions.

The main motor is driven by the MMD signal from ASIC. While the main motor is rotating, the MMD signal is driven to HIGH and  passed through IC35
to the control circuit in the main motor to rotate the main motor. The /MMRDY signal is kept HIGH until the main motor speed reaches the specified

rpm, and passed to the CPU.

The mirror motor is a stepping motor, and it uses the IC29 and the constant current chopper control IC (SLA7027). For control, the CPU outputs the

drive signal to the IC29 to drive the mirror motor with 1-2 phase excitement.

IC3A

IC2

RESET

VSB

VSA

VCC

NJM2103M

74VHC09

1

/RESET

3

2

7
6

2

1

3

8

4

NP

C2

VCC

1

C

1

1

C

2

0

.1

C3

CPU

RES

WDTOVF

5

IC1
CPU

MM

 IC31
Driver

IC32

2

18

4

96

97 /MMRDY#

MMD

14

/MMRDY

/MMD

IC5
ASIC

MIRROR
MOTOR

MMCC12

MMCC01

29

31

30

28

IC31

+

IC25

SLA7027MU

+

2200p

ICPN38

24V

/MMA
MMB

MMA

F6

2.4K

1.0(2W)

/MMB

4

7

/3

5

V

2.4K

2200p

1.0(2W)

4

7

0

p

4

7

0

p

6

2

0

1

00

6

2

0

4

7

K

5

1

0

4

7

K

22

/1

6

V

/MMRMO0

/MMRMO1

VCC

1

2

13

14

17

16

4

5

3

9

15

10

7

8

12

11

18

4

70
71

1

2

16

15

MIRMODA

MIRMODB
/MIRMODB

/MIRMODA

1

2

3

4

7

5

8

1

6

TDB

TDA

REFB

INA

RSA

INB

INA

INB

REFA

OUTB

VSB

VSA

RSB

OUTA

GA

OUTA

OUTB

GB