Ultrasonic Pest Repeller Circuit


Posted on Jan 1, 2013

This circuit uses two transistors and one IC (555 timer IC) to produce a pulsating ultrasonic frequency. Transistors Ql and Q2 are connected in a direct-coupled oscillator. The frequency of that oscillator is set by capacitor CI. The oscillator output is taken from the emitter of Q2 to pin 7 of IC1. Transistor Ql is an npn transistor, and Q2 is a pnp transistor. The signal of pin 7 on IC1 causes the output signal appearing on pin 3 to be modulated or varied by the audio frequency developed by Ql and Q2. The IC itself is connected as a stable multivibrator with a frequency that is determined by C3.


Ultrasonic Pest Repeller Circuit
Click here to download the full size of the above Circuit.

Capacitor C3 sets the basic frequency to be well above the human hearing range (ultrasonic). The combined modulated ultrasonic frequency appears on pin 3 of IC1, where it is coupled by capacitor C4 to the piezoelectric transducer.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Ni-cad charger
Low voltage flasher
Liquid-level-monitor
Telephone-controlled-night-light
4511B Common-Anode Display Driver Circuit
Electronic projects related to computers
make electromagnetic field
Solar Cell and Photovoltaic Circuits
1W LED Driver
650mA Micropower Low Noise Boost Converter with Output Disconnect
THREE FREQUENCY AUDIO OSCILLATOR



Top