Timer Based Mosquito Repeller Power Saver Circuit

Mosquito repellers have become really popular for keeping those annoying bugs away.

They work by using either ultrasonic sounds or chemical sprays.

However, these devices can use a lot of electricity when they are always running, which is not always needed.

To solve this problem a Timer Based Mosquito Repeller Power Saver Circuit has been created.

This circuit helps save energy by turning the mosquito repeller on and off at set times.

This smart design not only saves power but also makes sure the repeller does its job well.

The main part of this circuit is an astable multivibrator, which is made using the timer IC 555.

Circuit Working:

Parts List:

This circuit design makes use of the IC 555 timer which is set up to work as an astable multivibrator.

The 555 timer produces a continuous switching between HIGH and LOW signals which helps turn the mosquito repeller on and off regularly.

First the 230V AC power from the mains is reduced to a safer 12V AC using transformer.

Next this AC voltage is changed into direct current DC with the help of diodes D1, D2 and D3.

This DC voltage powers the whole circuit including the 555 timer and the relay driver.

The timing of the circuit is controlled by resistors VR1 and R1 along with capacitor C1 which together set how long the ON and OFF periods last.

As the 555 timer keeps switching between HIGH and LOW it creates a pulsed signal.

When the output is HIGH the relay turns on activating the mosquito repeller.

When the output goes LOW the relay turns off stopping the repeller.

This whole process happens automatically making sure the mosquito repeller works at regular intervals.

Additionally, transistor Q1 acts as a switch for the relay coil.

When the 555 timer output is HIGH Q1 allows current to flow powering the relay and turning on the repeller.

When the output drops to LOW Q1 stops conducting, which turns off the relay and the repeller.

Formulas with Calculations:

Below mentioned are the formulas with calculations for Timer Based Mosquito Repeller Power Saver Circuit:

Formulas and Calculations for Astable Multivibrator:

ON Time (THIGH​):

T_HIGH = 0.693 × (VR1 + R1) × C1

OFF Time (TLOW​):

T_LOW = 0.693 × R1 × C1

Total Time Period (T):

T = T_HIGH + T_LOW

Frequency (f):
f = 1 / T

Substituting the values from the circuit:

where,

• VR1 = 470k
• R1 = 10k
• C1 = 470µF

Calculate ON Time (T_HIGH)
T_HIGH = 0.693 × (470kΩ + 10kΩ) × 470µF
T_HIGH = 0.693 × 480,000 × 0.00047
T_HIGH = 156.2 seconds

Calculate OFF Time (T_LOW)
T_LOW = 0.693 × 10kΩ × 470µF
T_LOW = 0.693 × 10,000 × 0.00047
T_LOW = 3.25 seconds

Calculate Total Time Period (T)
T = T_HIGH + T_LOW
T = 156.2 + 3.25
T = 159.45 seconds

Calculate Frequency (f)
f = 1 / T
f = 1 / 159.45
f = 0.00627 Hz

This means the circuit will turn the mosquito repeller ON for about 156 seconds and OFF for about 3.25 seconds continuously repeating the cycle.

How to Build:

To build a Timer Based Mosquito Repeller Power Saver Circuit following steps are needed for connections of the circuit:

• Assemble all the components as mentioned in the above circuit diagram:
• Connect pin 1 of IC1 to GND of the circuit.
• Connect pin and pin 6 of IC1
• Connect positive of capacitor C2 from pin 2 and negative of capacitor C2 to GND.
• Connect pin 3 of IC1 to base of transistor Q1 through resistor R2
• Connect pin 4 and pin 8 of IC1 to positives supply of the circuit.
• Connect capacitor C3 from pin 5 of IC1 and GND
• Connect VR1 preset resistor one end to pin 6 IC1 and other end of VR1 to pin 7 of IC1
• Connect resistor R1 one end from pin 7 of IC1 and other end of R1 to positive supply of the circuit.
• Connect collector of transistor Q1 between diode D1 and 12V SPDT relay.
• Connect emitter of transistor Q1 to GND.
• Connect diode D2 and D3 to primary of transformer pins
• Connect one pin of output socket to transformer secondary pin and second pin of output socket to SPDT relay

Conclusion:

This Timer Based Mosquito Repeller Power Saver Circuit which uses the 555 chip works as a smart controller for mosquito repellers.

It turns the repellers ON and OFF at set times helping to save energy.

This way, the repellers do not waste power but still work well to keep mosquitoes away.

Plus you can change the timing to fit what you need making it a flexible way to save energy.

References:

DESIGNING AN ELECTRONIC MOSQUITO REPELLENT CIRCUIT