Panasonic FA-S280 Service Manual ▷ View online
2-6
Operation
2.3 Control Section
2.3.1
Enter Sensor and Exit Sensor
The Enter sensor and exit sensor are located on the paper insertion side (right
side) of the sorter. With no paper inserted, the light emitted from the LED of the
sensor reaches the phototransistor and the phototransistor turns ON. Therefore,
the outputs of both sensors are “L”.
When paper is fed from the copier, the enter sensor is activated. Then, the light
from the LED is blocked by the end of actuator so that the enter sensor output
becomes “H”. By monitoring this output signal, the CPU judges whether paper is
present or absent.
The exit sensor is used to detect a paper jam. The operation theory of the exit
sensor is the same as the enter sensor.
If paper remains over a predetermined period of time, the output of the exit sensor
is kept “H” so that the CPU judges that a paper jam has occurred.
SD001
VCC
RN2
CN5
Enter
Sensor
Sensor
Exit
Sensor
Sensor
RN4
RN2
RN4
PB4
PB5
ANODE
ENTER
GND
ANODE
JAM
GND
1
2
3
4
5
6
13
14
C12
C13
IC1 CPU
[CPU PCB]
2-7
Operation
2.3.2
Encoder Sensor, Bin Bottom Sensor and Bin Top Sensor
(1) Encoder sensor
As the lift motor turns, the disk of the encoder ass’y which has a slit turns.
When the encoder sensor detects the slit, the light from the LED of the encoder
sensor reaches the phototransistor and “L” signal is output from the encoder
sensor.
By counting the “L” pulse, the CPU monitors the current position of the bin
holder.
(2) Bin bottom sensor
When the bin holder reaches the lower limit and the shutter of the bin holder
comes in the bin bottom sensor, the light from the LED of the bin bottom
sensor is blocked by the shutter and the output of the bin bottom sensor
becomes “H”. This position is the lowermost position of the bin holder and is
referred to the home position.
(3) Bin top sensor
When the bin holder reaches the upper limit, the shutter of the bin holder
comes in the bin top sensor. In this condition, the light from the LED is blocked
by the shutter and “H” is output from the bin top sensor.
VCC
RN2
CN4
Encoder
Sensor
Sensor
Bin
Top
Sensor
Top
Sensor
Bin
Bottom
Sensor
Bottom
Sensor
RN4
RN2
RN4
RN2
RN4
PA4
PA4
PA4
ANODE
ANODE
LOWER
STEP
GND
ANODE
UPPER
GND
GND
IC1 CPU
[CPU PCB]
1
2
3
4
5
6
7
8
9
6
5
4
SD002
2-8
Operation
2.3.3
Paper Feed Motor Driver Circuit
The paper feed motor is a stepping motor that feeds paper onto the bin. It is
driven by the motor driver IC12.
The 1st-2nd phase exiting method is used to drive the paper feed motor.
OUTA
OUTA
OUTB
OUTB
IC12 Motor Driver
SLA7024M
SLA7024M
+24V
24VCOM
CN8
1
2
3
4
5
1
8
11
18
A
A
B
B
Feed Motor
M
[CPU PCB]
SD003
2-9
Operation
2.3.4
Lift Motor Driver Circuit
The lift motor is a DC motor that lifts up or down the bin holder. The motor is
driven by the motor driver IC11.
In addition to the thermal shut-down circuit incorporated in the motor driver IC, an
external overcurrent detection circuit is provided to shut down the power to the lift
motor.
It consists of photocoupler PC1, flip-flop IC and peripheral components. If, for
some reason, the lift motor keeps running and the bin holder runs over the upper
or lower limit, the bin holder mechanically stops.
In this case, as the lift motor spindle is locked, large current flows into the lift
motor. Then, the flip-flop is set via PC1 and the output of flip-flop becomes “H”. As
a result, the CPU stops the lift motor. Once this occurs, to reset the flip-flop,
power must be turned OFF.
VBB
SENS
OUTA
OUTB
IC11
Motor Driver
A3952SB
Motor Driver
A3952SB
10
16
+24V
11
15
15
A
B
[CPU PCB]
R1
R33
1
2
PC1
R24
3
4
C37 +
C36
VCC
D5
R20
R31
C26
R32
11
IC4
10
4
5
6
2
3
1
D7
R25
VCC
IC5
PR
CK
CL
Q
Q
D
+
CN7
DC+
DC–
Lift Motor
M
1
2
IC1 CPU
PB6
SD004
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