DFX-8500
Rev. B
2-2
2
2.3.3 Sensor Circuits

Figure 2-18 shows the sensor circuits in block diagram form. The printer is equipped with the f ollowing

sensors:

1. Front and rear PE sensors (use a photo interrupter)

2. Top PE sensor (to detect the TOF position, uses a photo interrupter)

3. Paper jam sensor (uses a magnetic transistor)

4. Tractor select sensor (uses a micro mechanical switch)

5. Pull tractor sensor (uses a micro mechanical s witch)

6. CR encoder sensor (uses a photo interrupter)

7. PG encoder sensor (uses a photo interrupter)

8. PG home sensor (uses a micro mechanical switch)

9. Ribbon jam sensor (uses a photo interrupter)

10. Cover open sensor (uses a micro mechanical switch)

11. Printhead temperature sensor (uses a thermistor)

12. Head fan temperature sensor (uses a thermistor)

13. Paper w idth sensor (uses a photo reflector)

14. CR motor isolation resistance sensor (monitored by the analog port of the CPU)

15. PSB/PSE board pow er off sensor (signal interface)

E05B36 (IC1)

CN4
ENCA
ENCB CR Encoder
3
4
CN14
PGENCA
PGENCB
35
34
148
149
ENCA
ENCB
PGENCA
PGENCB
28
25

CN14

CPU

TMP95C061 (IC2)

AN0
AN1
AN2
AN3
202122 23
Printhead Temperature
Head Fan Temperature
CR Motor Insulation
Paper Width
INT5
35
Cover Open

CN3

1

CN1

221929
Tractor Select
Pull Tractor
28
29
TRSEL
PTRCT
19
20
Paper Jam
Front PE
30
31
PJAM
FPE
21
22
Rear PE
Top PE
32
33
RPE
TPE
23
24
PG Home
Ribbon Jam
37
RBJAM 29
3618
PG Home
18

CN10

XNMI
10
POFF (SD)
8

Figure 2-18. Sensor Circuit Block Diagram