Sensors; Head Up Switch - Citizen CL-S6621 Technical Manual

2-2-3. Sensors

(1) Head up switch

The "SA, Head Up Switch" is used to detect the head position (up or down).
When the "Unit, Head" is closed (in the down position), the "Support Pop Up" of the "Unit,
Head" pushes the "Pop Up Cover Frame" and the "SA, Head Up Switch" pushes the lever of
the "SA, Head Up Switch" and the switch turns ON. Then, pin 117 (HDUSW) of U1A (CPU)
goes "Low" level.
When the "Unit, Head" is opened (in the up position), the "Support Pop Up" is disengaged from
the "Pop Up Cover Frame", the lever of the "SA, Head Up Switch" is set free, and the switch
turns OFF. Then, pin 117 (HDUSW) of U1A (CPU) goes "High" level.
U1A
CPU
117
PDH3
Head Up: High
Head Down: Low
SA, Head Up Switch
+3.3V
R80
HDUSW
C99
Unit, Head
Support Pop Up
Pop Up Cover Frame
Spring Pop Up
SA, Head Up Switch
J11
(Blue)
R78
Head Up Switch
1
2
[SA, Main PCB]
["Unit, Head" Down Position]
ON
SA, Head Up Switch
["Unit, Head" Up Position]
OFF
2-23
Operation of Control Parts
Support Pop Up
Pop Up Cover Frame
Spring Pop Up
CL-S6621