TTP-248M Bar Code Printer
Service Manual
3.11 Sensor Circuits
Ribbon Near End Sensor
The voltage of sender (PIN 3) is about 1.18V (1.17V~1.19V).
When the sensor detects the black area, the voltage of receiver (PIN 2) is≧ 2.10V.
When the sensor detects the white area, the voltage of the receiver (PIN 2) is≦ 1.26V.
|
| U3F |
U2/1 19 | 12 | 13 |
|
| |
|
| 74 HC14 |
VCC
R67
R64 10 0
10 0JP2
4
3
2
R251
10 K
GND RNE_ END
Fig. 3.9 Ribbon Near End Sensor Circuit
GAP Sensor
1.Selecting MANUAL GAP and adjust the tension.
When the tension increases, the voltage of the sender (PIN 5) will decrease; when the tension decreases, it will increase.
If adjust the voltage of PIN 5 between tension 000~255, it will alter between 4.4V~3.7V.
2.Selecting AUTO GAP to detect label will get a value of tension, and then selecting the MANUAL GAP.
When sensor detects the paper:
LCD displays Not Through the voltage of receiver (PIN 2)≦2.10V When sensor detects the gap or does not detect paper:
LCD displays Through the voltage of receiver (PIN 2)≧1.26V
Black Mark Sensor
Selecting MANUAL Bline, and adjust the tension.
When the tension increases, the voltage of the sender (PIN 6) will decrease; when the tension decreases, it will increase.
If adjusting the voltage of PIN 6 between tension 000~255, it will alter
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