🦟 Mosquito swatter electric circuit diagram: step by step

How are you all? I hope you are well. By the grace of God, I am also well. Today I will share with you the circuit diagram of a mosquito swatter.

Edited with Canva.

After opening an old mosquito swatter in my hand, I thought that if I could make a diagram of this circuit myself, then not only would I be able to teach it – but in the future, it would also be possible to teach others or make circuits like my own. From this idea, I designed each part of the circuit in PowerPoint and started to make it a reality one by one.

🛠️ Components used in the mosquito swatter circuit and the functions of electronic components

Many types of electronic components are used in a circuit. Each has its own function. Below I have given a brief explanation of each important component so that it can be remembered easily:

🔸 Diode

A diode allows current to flow in only one direction. It is used to prevent reverse current and create DC from AC.

🔸 Resistance or Resistor

A resistor limits the flow of current. Its function is to control the voltage and current in the circuit.

🔸 Capacitor

A capacitor holds a charge for a while and releases it when needed. It is used for filtering, preventing fluctuations and conserving energy.

🔸 Transistor

Transistors work as switches or amplifiers. It helps in converting low voltage to high frequency.

🔸 Transformer

A transformer works to increase or decrease voltage. It converts low voltage to high voltage, such as is needed to kill mosquitoes.

Here I have divided the entire circuit into 3 steps:

✅ Step 1: Getting AC from DC (Battery Charging Circuit)

First, I took 220-volt AC input through a 2-pin socket. Then I passed the line through a 100Ω resistor, and then I installed a 1N4007 diode so that there is no reverse current. I filtered it with a 105 capacitor (400V) and a 1M resistor next to it.

Then From here, I installed another diode (1N4007) and sent the charging line to the battery. I also installed a 100µF 25V capacitor so that there is no fluctuation during battery charging.

✅ Step 2: Converting the DC voltage of the battery to high voltage (Oscillator & Transformer Circuit)

Now I have got the charged power of the battery in DC form. To convert this DC voltage to high voltage, I used an oscillator circuit. Here, a push-pull type internal oscillation has been created using two transistors, a small transformer, some resistors and capacitors. In this, the power coil of the 3.7V battery is changed to a high frequency, which helps the transformer to output high voltage on one side.

✅ Step 3: Creating high voltage from the transformer secondary and reaching the mosquito net

I have installed two 0.01 µF V capacitors from the secondary output of the transformer to filter and stabilise the high voltage signal. Then I have made a bridge rectifier with 4 1N4007 diodes so that the AC signal can be converted to DC. I have further strengthened the high voltage coming out of this rectifier with a 2 µF 630 V capacitor.

Then I have sent this voltage to two meshes – an inner mesh (blue wire) and another outer mesh (red wire). These two meshes are very close to each other. When a mosquito or insect falls between these two meshes, a short circuit is created, and at that moment the insect dies due to a high-voltage shock.

🧰 Components used and their functions

Component name	Value	Function
AC input socket	2 pins	220V AC supply
Resistance (Resistor)	100Ω	Current limiting and safety
Diode (Diode)	1N4007 (x5)	Ensures one-way current flow (AC → DC)
Capacitor (Capacitor)	105 (400V)	Creates smooth DC by filtering AC
Resistance (Bleeder)	1MΩ	Drains the capacitor's charge quickly
Capacitor	100µF 25V	Keeps the voltage stable during charging
Li-ion battery	3.7V	Stores power and runs the circuit
Transistor	1 pcs	Works as an oscillator, generates frequency
Transformer	Small Ferrite Core	Increases voltage (Step-up)
High Voltage Capacitor	0.01µF 250V (x2)	Filters high frequency
Bridge Rectifier	1N4007 Diode (x4)	Converts AC signal to DC
Storage Capacitor	2µF 630V	Holds and releases high voltage
Mosquito Net (Mesh)	Two (Inner & Outer)	Destroys insects by applying high voltage

Last words:

I designed this circuit using PowerPoint and am trying to understand it by actually installing each part one by one. This is a part of my learning, where you can also check your bat's circuit like this if you want.

🟩 Thank you for reading my post and giving your valuable time. Stay well and stay healthy. God bless you. 🟩