Pest Chaser

Keep Mosquitoes and Insect pests away from your premises using this Ultrasonic Pest Chaser. Its frequency can be varied from 10 KHz to 90 KHz so that most of the insect populations can be repelled.

Most of the animals including insects can hear ultrasound which is annoying to them. So they avoid such situations. This Ultrasound generator uses the popular CMOS IC CD 4047 to generate Ultrasound. This IC is the precision Monostable / Astable IC and its oscillating frequency can be changed using C2 and VR1. In this design it is used as an Astable Multivibrator. With the given values of C2 and VR1, the output frequency can be adjusted from 10 KHz to 90 KHz. Most of the animals respond to 22 KHz to 60 KHz. Mosquitoes respond to 38 KHz. The ultrasound vibrations from the outputs of IC will be amplified by a set of Push-Pull amplifier T1 through T4.A Piezo tweeter is used as sound generator because the piezo element is designed to generate KHz signals. The circuit requires 9 to 12 volt supply which can be obtained from a PP3 battery.

Note:           Response to the circuit should be tested through observation. Response depends on the number of insects, their behavior etc.  Try different frequencies and find the suitable frequency of a particular insect group.