With this cool cat/dog repeller circuit you could chase the cats  off  from any where you want. In fact, I designed this circuit to chase my cat from my computer table. Most of the animals like cats respond violently to ultrasonic sound and in fact it’s the best way to chase them off. This principle is employed in this circuit.

The circuit here is nothing but an astable multivibrator wired around NE555 (IC1). The cat repellent circuit produces an ultrasonic sound in the range 15-20Khz. The NE 555 is enough to drive a small piezo buzzer and no amplification stages are needed. The POT R2 can be used to adjust the frequency of sound.

Cat Repeller Circuit diagram with Parts list. 



  • The circuit can be powered from a 9V battery or the power can be tapped from your computer SMPS.
  • The circuit can be assembled  on a general purpose PCB.

Authors view. 

I do not guarantee the full effectiveness of the circuit.You have try a lot of frequency settings to make your cat feel discomfort at last. More over the cat may get accustomed to the sound after some time. For me the circuit was only a partial success  and now my cat feels nothing even if the speaker is placed in it’s ear.You try your luck. Best of luck.



  1. Russel Harris

    Will this system work to scare Monkeys away from my bird feeders?

  2. shuvashish

    i want a circuit diagram of mosquito repeller using IC555 but no transistor. i also want the use of different part of that circuit like capacitor,resistor,IC. please send me.

  3. twits4twats

    A more effective frequency range for cats/dogs is 20-30KHz. Just remember, like humans, animals are succeptible to pain and age. In other words, they can also hurt from extreme noise and possibly even go deaf from extreme exposure. Also, as they get older, they tend to hear the higher frequencies less.
    For this circuit to damage anythings ears, it would have to be held in very closs proximity for extended periods of time.
    The cat/dog is well gone before this has been acheived, that is of course if the animal actually heard the noise to start off with.

  4. desperate

    mayby you save my life this cats kile at night I while tray today 🙂

  5. You have made your cat DEAF !!!
    Hopefully you circuit no longer works (possibly another reason the cat no longer responds), but if an animal runs away it is either scared or it’s painful!

    You should only use this circuit at a distance. The cats run away for a reason just like you would if someone put a air horn in your face !