Sharp AY-XP08CE Service Manual page 20

AY-XP08/10/13CE
AE-X08/10BE-C
AE-X13BE
What to Odor Sensor react to ?
Odor Sensor also may react to vapour of insecticides, cosmetics, alcohol, hemicals and the like, and to extreme change
of temperature / humidity.
(2) Detection of the air contamination by the fluctuation ratio of sensor resistance
The output voltage from the odor sensor is input into the microcomputer to detect the air contamination.
This method detects the air contamination by converting sensor output voltage into the sensor resistance value
and calculating its fluctuation ratio per unit of time. Therefore, the sensor determines that the air is contaminated
when the sensor resistance value drops abruptly.
Clean
Contaminated
Determined
clean
(3) Operation of the microcomputer
When the air conditioner is power on, the microcomputer starts operating and, after 1 minute, starts detecting the air
contamination.
(4) Switching sensitivity of the odor sensor
The sensitivity of the odor sensor can be adjusted when the sensor is too
responsive or unresponsive.
It is set as standard at the factory.
Sensitivity is divided into three levels: high, standard, and low.
The contamination is detected when the sensor resistance drops below
following percentages compared to the reference value in a clean state.
(This is equal to the description of the resistance of the allergen sensor.)
3. DESCRIPTION OF THE OPTIAL ALLERGEN SENSOR
(1) Outline of the optical allergen sensor
As with the odor sensor, this sensor is used to display cluster during the operation. The pulse signal is output
from the microcomputer into the basic circuit show in the figure below, and the sensor signal is input into the
microcomputer according to the size or amount of the dust.
Output
Input
Reference value (R0) Smoking start
Determined value K
Determined
contaminated
50Hz : 20.0 ms
60Hz : 16.6 ms
New reference value (R0)
Additional operation
1 min.
High (85%)
Standard (80%)
Low (75%)
Basic circuit
1
2
3
Allergen
sensor
4
5
6
20
Time
P.W.B.
R7 R6
15kΩ
15kΩ 13kΩ
13kΩ
12V
R39
C29
Q6
Input
R38
R40
Output
R72
C30