555 electronic sound repeller circuit

Electronic sound repeller

See Figure 1 for the working principle of the circuit (click here to download the schematic). It consists of a time control circuit, a cat sound generation circuit, and a power amplifier circuit. The time control circuit is composed of a time base circuit IC1 NE555 and its peripheral RC components, diodes and the like. It is a pulse oscillator with adjustable duty cycle and its duty cycle is controlled by R2 and R3. The cat sound generation circuit is operated by a CMOS integrated circuit IC2 KD-5605, which uses a storage technology to cure the meow sound inside the circuit. The power amplifier uses the inexpensive general-purpose low-power audio amplification integrated circuit IC3 LM386, which features few external components, wide voltage range, low distortion and simple assembly.
When the power switch S is closed, IC1 is energized, and there is a pulse output on the output pin 3 of IC1. When there is a pulse, the relay J is energized and attracted, and its normally open contact J1 is turned on, so that the rear stage circuit obtains power and works, and a meow occurs. Each time the IC2 is triggered, there is a cat called output, which is amplified by IC3 power. , push the Speaker BL to emit a loud and realistic sound. The mice were stunned and smashed.
See the table below for a list of component selection and manufacturing components.

After the circuit is soldered, the check is correct and the power can be debugged. The main reason is to adjust the interval between the cats and the R2, so that the interval is 1-3 minutes. Adjusting the adjustable resistor R5 on the IC21's foot can also make the cat's voice change to make it horrible. As long as the other circuits are soldered correctly, they can work normally without debugging.
After the circuit is adjusted, it will be placed in the place where the rats often go in and out at night, which can significantly reduce the rat damage.