Circuit design of electronic imitation mouse repeller

　　Cats are the natural enemies of rats, and using electronic devices to simulate cat sounds to repel rats is an effective method. Because it is an electronic device, the meow can be loud or soft, fast or slow, and the interval can be long or short. The circuit structure is simple and the cost is low, making it suitable for electronic enthusiasts to make their own home.

　　Circuit working principle: It consists of time control circuit, cat meow generating circuit, power amplifier circuit, etc. The time control circuit is composed of the time base circuit IC 1NE555 and its peripheral resistor-capacitor components, diodes, etc. It is a pulse oscillator with an adjustable duty cycle, and its duty cycle is controlled by R2 and R3. The cat's meow generating circuit is played by a CMOS integrated circuit IC2KD-5605, which uses storage technology to solidify the cat's meow inside the circuit. The power amplifier uses the inexpensive and high-quality universal low-power audio amplifier integrated circuit IC3LM386, which is characterized by very few external components, wide voltage range, low distortion, and simple assembly. Turn on the power switch S, IC1 will be powered on and work, and there will be continuous pulse output on the output terminal ③ pin of IC1. When there is a pulse, relay J is excited and closed, and its normally open contact J1 is connected, allowing the subsequent circuit to obtain power and work. A cat meow occurs. Every time IC2 is triggered, a cat meow is output. After being amplified by the power of IC3 , push the speaker BL to produce a loud and realistic sound. It makes the rats frightened and achieves the purpose of driving away rats.

　　For the selection of components, IC1 uses the 555 time base integrated circuit; IC2 uses the KD-5605 sound integrated circuit; IC 3 uses LM368. The relay uses the JRX-13F small relay , and the speaker BL should choose a speaker of 8Ω, 3W or more or a special horn-type speaker , the rest of the components have special requirements. After the circuit installation is completed, as long as the wiring is correct, it can generally be used normally without debugging.