The document describes how to build a simple mosquito repellent circuit using a 555 timer IC that generates a 40 kHz sound frequency through a piezo buzzer to repel mosquitoes in an efficient and safe manner. The circuit requires a 555 timer IC, piezo buzzer, resistors, capacitor, battery, and breadboard to connect the components. The 555 timer IC is configured in astable mode to produce the 40 kHz oscillation fed to the buzzer, generating the high frequency sound to repel mosquitoes without the health effects of other solutions.

1. Using 555 TIMER IC

2. INTRODUCTION
• Various mosquito repellent solutions like
oils, liquid vaporizers, and creams, all have
possible adverse effects to health.
• Electronic mosquito repellents are available
in market which are equally efficient and
relatively safe.
• The concepts of these mosquito repellers are
simple and we can build a simple mosquito
repellent circuit at home easily.

3. Motivation
. Mosquito spread disease like maleria,
chickun guniya…etc.
. Reppelent circuit is cheap and efficient.
. Simple method and concept.

4. Basic circuit

5. BREADBOARD CONNECTION

6. Components Required
• 555 Timer IC
• Buzzer
. Resistors - 1k and 1.3k
( variable resistor of 10k )
• Capacitor - 0.01µF
• Battery - 9v
• PCB and Connecting wires

7. Principle
 555 timer IC in Astable mode, produce
40 kHz frequency sound.
 Buzzer connect at the output (PIN 3) of 555
timer IC to generate sound of desired
frequency.
 So, High frequency Piezo buzzer is used.
 Arrange the resistors and capacitors to produce
oscillation of 40 kHz frequency.