Opc Life Sensor Circuit - Panasonic KX-MB2230JT Service Manual

KX-MB2230JT/ KX-MB2270JT/ KX-MB2515JT/ KX-MB2545JT/ KX-MB2575JT/ DP-MB310JT

6.12.15. OPC Life Sensor Circuit

1. General
This circuit detects whether the OPC is brand-new or secondhand.
And if Drum cartridge is detected as brand-new, after predetermined printing, Fuse, which is installed inside of the OPC is cut.
After cutting the fuse, the OPC is judged as secondhand, and OPC life counting starts.
This circuit consists of Fuse cut block and OPC type detection block.
2. Circuit diagram
OPC Contact Board
1st use Board
3. Circuit Explanation of Fuse cut block
When IC300_pinK26 is "H", Q600, Q601 and Q602 are turned on. Then current flows F99 through R600/R601. Conse-
quently Fuse is cut within 1 second.
R600 and R601 are supplied to protect Q600 and Q601 from the fuse cut current.
4. Circuit Explanation of OPC type detection block
This block detects whether OPC is brand-new or secondhand.
And also detect if the contact of the terminal is normal or abnormal (contact error).
(1) In case of Brand-new Drum
Since Fuse is not open, resistance between the fuse is approx. 4ohm.
So the voltage level of point A in the above circuit diagram is less than 1V.
As the result, both Q604 and Q605 are turned on.
(2) In case of secondhand OPC
When Fuse is open, resistance between the fuse is determined by the resistance of R99 (220ohm).
Since the resistance of R609 is 120ohm, the voltage level of point A in the above circuit diagram is approx. 3.5V.
Consequently Q605 is turned on and Q604 is turned off.
(3) In case of contact error of the terminal
Since both F99 and R99 are open condition, resistance between the fuse is infinite.
So the voltage level of point A in the above circuit diagram is approx. 5V.
Then both Q604 and Q605 are turned off.
According to the above transistor condition, the logic level of IC300_pinY24 and Y25 are changed as below table.
Thus by checking these 2 signal levels, drum cartridge condition can be detected.
24V
CN79 CN506
1
1
5
5
F99 R99
OPC _Unit
OPC_CNTCT
(IC300_pinY24)
L
H
L
H
Fuse cut block
R607
Q601 R605
S5V S3.3V
D600
R604
Q604
S5V
A
Q605
OPC type detection block
OPC_LIFE OPC status
(IC300_pinY25)
L contact error
L Secondhand
H (Not used)
H Brand-new
76
Main Board
IC302
Q602
11
OPCFUSECUT
IC300
Y25
OPC_LIFE
Y24
OPC_CNTCT
R611