Panasonic KX-TDA0103XJ Service Manual page 60

KX-TDA0103XJ / KX-TDA0104XJ / KX-TDA0108XJ / KX-TDA0103X / KX-TDA0104X / KX-TDA0108X
4) Over Voltage Protection Circuit
When any of 15V, 15VPT, 30V and main converter 41V output becomes abnormal, the voltage is sent to the abnormal detection
circuit through zener diode D529 (on Sub board2).
Refer to Fig. 6 (B).
8.3.1.7. FAN Block
This section explains about FAN and FAN alarm signal sending circuit.
1) Dropper circuit
The 15V output voltage is dropped to 12~13V by the constant voltage circuit consisting of Q591 and zener diode D591 to be
fed.
Refer to Fig. 7 (A).
2) FAN Circuit
When the constant voltage controlled by dropper circuit is supplied to between terminal 1 (plus) and terminal 2 (minus), the FAN
starts to rotate. The sensor output is low while the FAN is rotating, and the sensor output becomes high when the FAN stops.
Refer to Fig. 7 (B).
3) FAN Alarm Signal Sending Circuit
Q592 is OFF while the FAN is rotating, and the FAN alarm output becomes OPEN.(No voltage is added between the base and
the emitter of Q592 because sensor output is low.)Q592 becomes ON when FAN is stopped, and the FAN alarm output
becomes LOW.(Voltage is added between the base and the emitter of Q592 because sensor output is high.)
Refer to Fig. 7 (C).
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