Types of Mosquito Repellents and Circuit Operation using IC 555

In recent years mosquito is one of the harmful insect for mankind owing to the deadly, infectious diseases associated with the mosquitoes’ bites: malaria, elephantiasis, yellow fever, etc. Malaria is a major disease that mostly affects the people living in humid and other parts of the world. Children below five years age are often susceptible to the diseases spread by mosquitoes. Every year millions of people get affected by malaria resulting in a million deaths. To kill mosquitoes and prevent their spread, there are several approaches such as killer spray, oils, coils, machines perfumes, etc. For the most efficient outcomes without involving any side effects, the best solution is to build an Electronic mosquito repellent by using basic electronic components. It is the most popular way to repel mosquitoes as it is very convenient to use.

Nowadays different types of mosquito repellents are available. The repellents that are made from chemicals and plants and the ones that are available in the form of NN diethyl benzamide and DEET, lotions, sprays, creams, liquid vaporizer, foams, coils, mats, and essential oils are quite common. The Electronic mosquito repellents that are broadly available use electromagnetic and ultrasonic waves to resist mosquitoes and insects.

Types of Mosquito Repellents

As there are lots of mosquitos repellents available to choose from, we do not always need to rub and spray to protect ourselves from mosquitoes and insects.

1. Spray Repellents

Spray repellents are quite common and are used mostly on surfaces like walls, clothes or skin. Spray repellents with their high concentrations of DEET (diethyl-meta-toluamide) are very effective for several hours even after walking around in spaces with hundreds of mosquitoes.

2. Lotion or Cream Repellents

Cream and lotion repellents can be applied directly to the skin and such types of creams or lotion based repellents form good solution in combination with repellent clothing. These repellents can be found in natural solutions that have little smell.

3. Insect or MosquitoRepellent Clothing

Mosquito repellent clothing is designed with tight fiber woven fabrics with a long lasting insect repellent to prevent mosquitoes and insect bites. Mosquito repellent clothing is a very good solution for everyday insect protection. These repellents are becoming more common nowadays.

4. Mosquito Repellent Devices

Mosquito repellent devices emit a fragrance by burning repellent stuff and these repellents include coils, candles and ThermaCell products. Coils and candles have low effectiveness, but ThermaCell products are very effective for camping, picnics etc.

5. Natural Mosquito Repellents

Natural mosquito repellents work best, whereas DEET based mosquito repellent do not work as such because many research studies have proved that the main element in mosquito repellents often leave bad odor. Apart from this, chemical based repellents like DEET damage brain cells and also cause behavioral changes. Scientists have also observed that such repellents may damage and cause cells’ death in animals after prolonged exposure to DEET. Other research studies have found that up to 15% of DEET is observed directly through the skin and into the blood. In view of all such findings, there is no need for people to suffer from long-term health related consequences of chemical-based mosquito repellents as the natural mosquito repellents are the best and work efficiently than DEET.

Natural mosquito repellents include catnip, citronella, garlic, lavender, Neem oil, organic soy oil, lotus and black pepper. Mix 30 drops of essential oils they are catnip, citronella, lavender, neem oil and black pepper into 30ml of moisturizer and Rub a small portion of it onto the skin.

6. Mosquito Repellent Machine

India has a large and growing market for mosquito repellents –and, in spite of the popularity of the mosquitoes problem, the usage of the mosquito repellent machines in India is somewhat less; for instance, rural areas account 6.9%, metros 22.6%, and urban areas 16.4%. In terms of value, the use of mat segment account 51%, coils segment 21%, and vaporizers segment 7%. A Mosquito repellent machine attracts and kills mosquitoes population and these machines are durable and give long life. Mosquito repellent machines are used in bedroom, washroom, living room, offices, etc.

Electronic Mosquito Repellent Circuit

Circuit Description

A multivibrator is an electronic circuit which is used to generate a pulsed output signal. Usually, multivibrators are classified into different types based on the stability of the output. Here the common form of a stable multivibrator is 555 Timer IC, which is used in this electronic mosquito repellent circuit, and it consists of 8 pins. Astable multivibrator can be used as an oscillator and it doesn’t require external triggering. The 555 timer pin description is described below.

• Pin1 is connected to the negative terminal of the battery.
• Pin2 is a triggered active low pin, which is directly connected to the pin6 for astable operation.
• Pin3 is an output pin.
• Pin4 is a reset pin, which is an active low pin directly connected to the positive terminal of the battery.
• Pin5 is the control pin connected to the ground through a microfarad capacitor.
• Pin6 is the threshold pin that is shorted to pin2 and connected to pin7 using a resistor for astable operation.
• Pin7 is the discharge pin that provides a discharge path for the capacitor.

Circuit Operation

When the switch is closed, the 555 timer IC circuit gets the power supply, and then the capacitor voltage and triggered pin2 become zero. Here, the capacitor charges through the resistors R1 and R2. When the voltage at the pin6 is less than the capacitor’s voltage, it causes a change in the output. The capacitor starts discharging through the resistor R2 through the discharge pin7 and continues until the output voltage is back to the original. Thus, the piezo buzzer generates the output signal with a frequency of 38 KHz with regular repetitions. When the potentiometer value varies, the output frequency can also be varied. This high frequency sound is thus allowed to be heard by the incoming insects or mosquitos, and thus leads them to fly away or leave from the circuit and surrounding areas due to annoying sound.

By some changes to the values of the capacitors and resistors, this circuit can also be used as another insect repellent and can also be used as a buzzer alarm circuit.

Thus, an electronic mosquito repellent circuit keeps us safe from mosquitos and insect by using very high frequency sound. Have you got any idea of all the above mentioned mosquito repellents and especially the electronic ones and with a keen interest want to develop the use of microcontroller? If your answer is yes, then please comment below – we are ready to provide such circuit with complete and apt explanation along with the coding as well.Please refer the following link for: Electrical and Electronic projects

Photo Credits

• Electronic mosquito repellent by chinaoppo
• Spray Repellents by scjohnson
• Natural Mosquito repellents by ecobrooklyn