Ultrasonic Insects, Rodents and Martens Repellent with 555 Timer

In this electronics project, I will show you ultrasonic insects, rodents and martens repellent circuit with a 555 timer.

This repeller produces ultrasonic tones with a periodic change frequency of about 29kHz, which is inaudible and not harmful to humans.

But, that sonic tone is allergic to uninvited guests such as mosquitoes, mice, rats, marten, or spiders therefore, it can reliably repel them.

Circuit Diagram

Schematic of the ultrasonic insects, rodents, and martens repellent circuit is shown below.

[Components used - U₁: NE555N, R₁:100K, R₂:27K, R₃:27K, R₄:1k5, C₁:220pF, C₂:100nF, PZ₁: 5V Pizzo-electric speaker]

Circuit Explanation

The working principle of ultrasonic insects, rodents and martens repellent circuit or pest repellent circuit is simple.

The input voltage of the circuit is DC 6V to 9V, 500mA.

A single 555 timer is the main component of the circuit and is set as an astable multivibrator.

The output switching frequency is realized by changing the voltage at the 5^th pin of circuit 555 IC (U₁), which is ensured by the blinking LED (LED₁).

The frequency changes range from about 15 - 29kHz, so the insect (including mosquitoes) and animals can't build immunity against the ultrasonic tone.

The source of ultrasonic tone is the piezo-electric speaker (PZ₁).