Citizen CLP-631 - Mode Settings - Menu Options

2-2. Operation of Control Parts
2-21 CLP-621 & CLP-631
(3) Sensors
(3-1) Head up sensor
The head up sensor is used to detect the head position (up or down). This sensor uses a
photointerrupter.)
When the head block is closed (in the down position), the protrusion “A” of the head block
is engaged in the head up sensor, and the light emitted from the LED of the
photointerrupter is blocked by the protrusion “A”. Thus, the phototransistor turns OFF, and
pin 117 (HDUSENS) of IC1 (CPU) goes to "High" level.
When the head block is opened (in the up position), the protrusion “A” is disengaged from
the head up sensor, and the light emitted from the LED reaches the phototransistor. Thus,
the phototransistor turns ON and pin 117 (HDUSENS) of IC1 (CPU) goes to "Low" level.
[Main PCB]
[Head Up Sensor PCB]
Head Up Sensor
IC1
CPU
2
3
1
+3.3V
HDUSENS
R124
CN9
R116
R115
R114
C75
117
D19
+3.3V
Head Up: Low
Head Down:High
C74
P220
Head Up Sensor
(SA, Head Up Sensor PCB)
Head Block "Up" position
Head Block "Down" position
Head Block
SA, Head Up Sensor PCB
SA, Head Up Sensor PCB
Photo
Interrupter
Photo
Interrupter
A
A
A