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KX-MB1536RU

1. General

One motor driver IC controls both Main motor and FB motor.

Engine motor drive circuit consists of "Motor driver" and "Motor current control circuit".
All driving forces of printer engine part are supplied by tis engine motor.
Engine motor is controlled so as to rotate at constant speed while printing and copying.

FB motor drive circuit consists of "Motor driver", "Motor current control circuit", and "O.C.P (Over Current Protection) circuit".
FB motor feeds CIS unit in FB scan, FB copy, and FB FAX mode.
A one step rotation of this motor feeds CIS unit 0.021mm. 

2. Block diagram of Main and FB motor drive circuit

IC600 is the motor driver AN44071A.
This motor driver can drive both Main and FB motors with 1 chip, and can supply up to 1.7A/phase and support up to 2W1-2
phase excitation.
When "ENABLEAB" signal (IC600_pin40) becomes "H", FB motor driver block of IC600 is activated, and motor currents are
supplied from IC600_pin24, pin28, pin29 and pin33 to drive the FB motor coils.
When "ENABLECD" signal (IC600_pin45) becomes "H", Main motor driver block of IC600 is activated, and motor currents are
supplied from IC600_pin1, pin5, pin52 and pin56 to drive the Main motor coils.

FB motor excitation mode is selected by the logic level of "ST1AB", "ST2AB" and "ST3AB" (IC600_pin35-pin37).
Main motor excitation mode is selected by the logic level of "ST1CD" , "ST2CD" and "ST3CD"(IC600_pin50-pin48).

The relation between motor excitation mode and logic level of "ENABLEAB"/"ENABLECD", "ST1AB"/"ST1CD", "ST2AB"/
"ST2CD" and "ST3AB"/"ST3CD" are shown in below table.

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KX-MB1536RU

Table1: Motor driver Excitation mode                                               *(pinxx) represents the pin No. of IC600

"DIRAB"(IC600_pin38) and "DIRCD"(IC600_pin47) determine the direction of motor rotation.
Although "DIRCD" determines the Main motor rotation direction, direction is  not changed.
So "DIRCD" is fixed "H" level.
The relation between "DIRAB" and motor rotation direction are shown in below table.

Table2: FB motor rotation direction                                                  *(pinxx) represents the pin No. of IC600

After setting the above signals, clock signal is supplied from IC300_pinB21 to "CLKAB"(IC600_pin39) and from
IC600_pinC26 to "CLKCD"(IC600_pin46).
Whenever clock signal is supplied, current value and direction supplied to FB and Main motors change according to
the excitation mode which is determined by above signal levels.
The clock frequency also determines the motor speed.

1. Function

According to the scan speed or printing speed, motor current is controlled for appropriate value.
For example, when scan or print 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 or main speed is high, motor needs much driving force. so much current should be supplied.
In order to control the motor current, VREFAB and VREFCD voltages of IC600 is controlled.
When VREFAB and VREFCD voltages are high, motor currents are increased, and the voltages are low, motor currents are
reduced. 

2. Circuit Diagram

Please refer to the circuit diagram shown in the block diagram of Main and FB Motor Drive Circuit (P.33).

3. Circuit explanation

For the control of VREFAB and VREFCD voltage, PWM pulses are supplied from IC300_pinC23 (for FB motor) and pinE24
(for Main motor).
•FB motor

PWM pulse is integrated by R671, R672 and C657, then converted to DC voltage.
This DC voltage is supplied to VREFAB pin of IC600.
*This circuit is commonly used for the control of Vref voltage of ADF motor driver. 

•Main motor

PWM pulse is integrated by R658 and C653, then converted to DC voltage.
This DC voltage is supplied to VREFCD pin of IC600.

When duty of PWM pulses are high, VREFAB and VREFCD voltages are increased and when duties are low, VREFAB and
VREFCD voltages are decreased.

ENABLEAB(pin40)

or

ENABLECD(pin45)

ST1AB(pin35)

or

ST1CD(pin50)

ST2AB(pin36)

or

ST2CD(pin49)

ST3AB(pin37)

or

ST3CD(pin48)

Excitation 

mode

FB motor oper-

ation

Main motor 

operation

L

-

-

-

Disable

Stop

Stop

H

L

L

L

2 Phase

Not used

Full speed

H

L

H

L

N1-2phase

High speed

Half speed

H

H

L

L

F1-2phase

Medium speed

Not used

H

H

H

L

W1-2phase

Low speed

Not used

H

L

L

H

2W1-2phase

Not used

Not used

Motor

DIRAB(pin38)

Operation Mode

FB

L

Scan

H

Return

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KX-MB1536RU

4. Timing chart of current control

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

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

1. Function

If motor driver can supply more than 15 watts, FB and ADF motors may become fire hazards.
To prevent the risk of fire, this circuit is provided.
 

2. Circuit diagram

3. Circuit explanation

When the current supplied from 24V exceeds 0.44A, the voltage between two registers R657 and R658 becomes more than
0.6V (=0.44Ax2.7ohm/2), consequently both Q650 and Q651 turn on, then "ENABLEAB" signal (IC600_pin40) becomes
"Low" level.
When "ENABLEAB" signal becomes "Low" level, FB motor drive block of IC600 is deactivated and currents of FB motor are
cut off.
So the currents which IC600 can supply are limited to less than 0.44A and the wattage is also limited to less than 10.6W
(=0.44Ax24V).
By limiting the wattage less than 15W, risk of fire hazard is eliminated.

Also "CRM1"siglal is provided from IC300_pinA21 to base of Q651.
This signal is designed to become "High" when software can not control motors properly by some accidents.
When base of Q651 becomes "High", "ENABLEAB" signal becomes "Low" and FB motor currents are cut off.
Therefore even in the case of software can not control motors, FB motor stops automatically for securing safety.

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KX-MB1536RU

1. General

ADF motor drive circuit consists of “Motor driver”, "Motor current control circuit", and "O.C.P. (Over Current Protection) circuit".
ADF motor feeds documents in ADF scan, ADF copy, and ADF FAX mode.
A one step rotation of this motor feeds documents 0.042mm.

2. Block diagram of Scanner motor drive circuit

Motor driver IC700 can drive motors up to 0.8A/phase and support up to W1-2 phase excitation.
When "Power save" signal (IC700_pin20) becomes "H", motor driver is activated.
Stepping pulses are output from IC300 pins A21, B21, B22, C22, A22, and B23.
Frequency and pattern of these pulses determine the motor rotation speed and excitation mode respectively.
Corresponding to these pulses, current are supplied from IC700_pin4, pin6, pin7 and pin9 to ADF motor coils.

This circuit is same as "Motor current control circuit" of FB motor.

1.Function
If motor driver can supply more than 15 watts, FB and ADF motors may become fire hazards.
To prevent the risk of fire, this circuit is provided.