Hitachi RAF-25RPA Service Manual page 57

6
• When the buzzer sounds, an approx.
3.9kHz square signal is output from
buzzer output pin 83 of the micro
computer. After the amplitude of this
signal has been set to 12Vp-p by a
transistor, it is applied to the buzzer.
The piezoelectric element in the buzzer
oscillates to generate the buzzer's sound.
R6
+
66
INPUT
GND
57