Now i am going to introduce you an All in one Repellent circuit.
Ya i mean it, by using this circuit you can keep nasty insects,
Mosquitoes, lizards, and dogs away. Lets look the PRINCIPLE of
this circuit:- This circuit works under the Principle of
Ultrasonics. As you may know, we can't hear Ultrasonic sounds
but animals or insects like Mosquitoes, bees, lizards and even
dog can hear Ultrasonic sounds well. How this repellent circuit
keeps Insects, lizards, Mosquitos and Dogs away? As i mentioned
above, they can hear Ultrasonic sonic sound well at a particular
Frequency range. Above that, they may get IRRITATED
continuously. That's how this repellent circuit works. The ALL
in one REPELLENT CIRCUIT mainly consisting of a 555 timer,
Frequency determining network, and a buzzer. The 555(NE555)
timer is wired here as an ASTABLE MULTIVIBRATOR, which will
generate Square waves continuously upon the power supply of 12V.
The output Voltage from pin3 of NE555 is given directly to a
Buzzer by a COUPLING capacitor C2. Th