Panasonic KX-F900 Service Manual page 144

KX-F900
[Cover Open Sensor (SW271)]
When the upper cabinet is closed, the plate push the switch lever, the input signal of IC151-33pin (ANALOG)
becomes low level. When there is opened, the plate leaves the switch lever, the input signal of IC151-33pin (ANALOG)
becomes high level.
l
o/o
Analog Board
Signal (IC151-33 Pin)
Close Low level
Open High level
IC151
[Read Position Sensor (PI301)]
When an document is brought to read position, the shelter plate pass the sensor light, the phototransistor becomes ON,
and the input signal of IC301-15pin (Operation) becomes low level. When there is no document at the read position, the
shelter plate shuts the sensor light, the phototransistor becomes OFF, and the input signal of IC301-15pin (Operation)
becomes high level. (When checking this sensor condition, IC301-16 pin becomes low level).
+5V
SHELTER PLATE
+5V
i
i i
i
, i
1
i i
i i
R331
IC301
15
XLD12
16
-- LED11
Operation Board
Phototransistor Signal (IC301-15 Pin)
Out of the Read Position OFF High level
At the Read Position ON Low level
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