KX-MB2110RUW, KX-MB2130RUW, KX-MB2170RUW, KX-MB2117RUB, KX-MB2137RUB, KX-MB2177RUB - Panasonic Copying Equipment Service Manual (repair manual). Page 41

41

KX-MB2110RUW/ KX-MB2130RUW/ KX-MB2170RUW/ KX-MB2117RUB/ KX-MB2137RUB/ KX-MB2177RUB

General

Scanner motor drive circuit is consist of motor current control circuit ,FB (Flat Bed) motor driver, ADF motor driver and OCP (Over
Current Protection) circuit.

1. Function

According to the scan speed, motor current is controlled for appropriate value.
For example, when scan speed is low, motor has enough driving force.
So to prevent the vibration and noise during motor rotation, motor drive current should be reduced.
When scan speed is high, motor needs much driving force. so much current should be supplied.
In order to control the motor current, VREFA and VREFB voltages of IC600 is controlled.
When VREFA and VREFB voltages are high, motor currents are increased, and the voltages are low, motor currents are
reduced. 

In order to control the Vref voltage, PWM pulse is supplied from IC300 pin C23.
PWM pulse is integrated by R601, R604, and C601, then converted to DC voltage.

This DC voltage is supplied to Vref pin of each motor drivers.
When duty of PWM pulse is low, Vref voltage is decreased and when duty is high, Vref voltage is increased.

For FB motor, motor current is controlled approx. 0.18A-0.3A.
For ADF motor, motor current is controlled approx. 0.30A-0.37A.

2. Circuit Diagram

3. Timing chart of current control

Following timing charts are the example of  Vref voltage corresponding to PWM pulse duty.

FBMEN

(ADFMEN)

CRM0
CRM1
CRM2
CRM3
CRM4
CRM5

PWD

IC300

R601

C

601

A

B

R

604

A24

B21
A21
C22
B22
A22
B23

C23

Current control circuit

O.C.P. circuit

VM1, VM2
ENABLE

PHA1
PHB1
IN0
IN1
IN2
IN3

Vref

BOUT2

BOUT1

AOUT2

AOUT1

IC600 (IC700)

1, 15

31

25

26
27
28
29
30

19, 20

CN600

(CN701)

3

7

9

13

1

2

3

4

Main Board

FB Motor

(ADF Motor)

24V