REV.-A
2.3.3
Sensor Circuits
The
printer has the following sensors:
(FRONT),
(REAR),
(platen
RELEASE LEVER, and HEAD TEMPERATURE. All the sensors are momentary switches, except the PE (REAR)
sensor, which is a photo diode, and the HEAD TEMPERATURE sensor, which is a thermistor.
In addition to the sensor circuits, the +35 V monitor circuit and the
circuit are also provided. The +35 V
monitor circuit is used to set the pulse length of the head drive signal. If the voltage of the +35 V line drops
below
V
the printer stops printing fora while. As soon
recovers, the printer starts
to print at a half speed. (The PF motor also slows down.) The
circuit is used to supply the reference voltage
for the A/D convertor in the CPU.
The CPU constantly monitors the
temperature. If the
temperature exceeds the maximum
level, the printer stops printing until the temperature drops to a certain level. When the
temperature
cools down, the printer resumes printing automatically.
Figure 2-26 shows the sensor circuit block diagram.
.
..-.
CPU
PEFRONT
PEREAR
PG
+35
v
RELEASE
LEVER
+35 Voltage Monitor
Head Temperature
+35
v
ZD1
Figure 2-26. Sensor Circuit Block Diagram
2-26
Содержание FX 1170 - B/W Dot-matrix Printer
Страница 1: ...EPSON EPSON TERMINAL PRINTER FX 870 1170 SERVICE MANUAL 4001461 REV A ...
Страница 5: ... f REVISION SHEET REVISON DATE ISSUED CHANGE DOCUMENT A June 15 1992 1st issue 7 v ...
Страница 11: ...REV A 4 80 column model 136 column model Figure 1 1 External View of the FX 870 1170 r 1 2 ...
Страница 128: ...REV A Figure 6 1 Lubrication Points 6 3 ...
Страница 134: ...d 4 r I m 0 C2 c O EN l I t J 1 I I m I I k I 1 _ m u Figure A 4 BOARD ASSEMBLY C076 PSB Circuit Diagram Annotated A 7 ...
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