High-loudness alarm sound generator circuit design

　Working principle of the circuit: This circuit is mainly composed of the sound-generating integrated circuit KD~9561 and the switching integrated circuit TWH8778. When working, the KD-9561 outputs the alarm signal, which is processed and amplified by the TWH8778 high-current switching integrated circuit to push the speaker to emit a loud alarm. Voice. The IC uses KD-9561 sound IC, or you can choose KD-9562 sound IC, and wire it according to the requirements to make it sound the alarm signal. IC2 uses the TWH8778 switching circuit. When the power supply voltage is 12V, the speaker BL should choose a speaker of 8Ω and above 3W or a special horn-type speaker. The resistance of the current limiting resistor R1 is 300Ω~510Ω. D2 uses a 3V voltage regulator tube. D1 is the circuit For protection diode, 1N4001 can be selected. After the circuit installation is completed, as long as the wiring is correct, it can generally be used normally without debugging.