This is an ultrasonic sound based project which can be directly connected to an AC line. Ultrasonic means out of human hearable of frequency above 20kHz because human can hear sounds in the range of 20Hz to 20kHz. The project is made to generate a frequency around 40kHz through a piezo buzzor or speaker.
This ultrasonic sounds of high amplitude can be able to disturb some creatures like mosquito, rat and some bugs. I can’t say about its 100% working for all type of creatures but I got it’s function when trying on rats. To change the ultrasonic frequency, vary the 47k preset in a suitable position. Use good quality speaker for better accuracy. Do not touch on the pcb during operation as it is directly connected with high voltage AC line.
If you have made this project, please share your personal experience about this project.