Sensor Board; Paper Gauge Sensing Circuit - Kyocera FS-1800 Service Manual

(3) Sensor board

Paper gauge sensing circuit

Paper gauge operates in four levels of paper remaining in the cassette. The height of the paper stack
in the paper cassette changes the angle of the actuator. At the end of the actuator is a reflecting
mirror which reflects or interrupts the light emitting from photointerruptor sensors PH702 and
PH703 accordingly.
These two sensors generate four digital signals which will be digital-analog-converted and input to
A/D port of CPU. CPU then issues signals according to the level of the analog signals. The resultant
signals are used to monitor the amount of paper in the cassette through the network management
utilities.
Paper feed unit
Sensor board
Paper gauge
sensor 1 (PH702)
Paper gauge
sensor 2 (PH703)
Acutuator
(Reflecting mirror)
Actuator
position
PH702
PH703
Figure 4-3-10 Paper gauge sensor(s)
4-33
Sensing input
Paper
gauge
PH703
PH702
Empty H
1/4 to 1/2
L
1/2 to 3/4 L
H
3/4 to full
FS-1800/1800N | FS-3800/3800N
D/A converted
output
approximately
H
5 V
approximately
H
2.25 V
approximately
L
1.95 V
approximately
L
3.9 V