Saturday, October 28, 2017

How the mosquito racket / bug zapper / fly swatter high voltage generator works.

One of the simplest electronic components that most people overlook is the mosquito racket or most commonly called (bug zapper or the fly swatter). The circuit is very simple consist of 3 major parts as follows.

The charger parts: 1, 2, 3, 4, 5, 6

The DC to AC inverter parts: 8, 9, 10, 11, 12, 13

Voltage Multiplier parts: 15, 16, 17, 18, 19, 20, 21

We are going to replicate how the circuit works using only the necessary components as follows:

No.11: NEC D882P NPN Transistor
No.12: 650 Ohm Resistor
No.13: High voltage mini-transformer (6 pins)

And all the voltage multiplier components

3 High voltage diode rectifier RFC4K
221K 4KV Capacitor (220 pF)
CBB81 223J2KV (0.022 uF 2KV Metallized Film)
2 x Unknown capacitor which i believe it is around 2KV to 4KV

The re-assembly of the circuit will be as look like the schematic diagram as shown below

Below is the video demonstration step by step how to re-assemble the circuit. Note that the circuit output is not as efficient as the original because of the loose connection on the breadboard. It would be much more efficient if it is soldered permanently.

Many people have underestimated this bug zapper and it actually the most use components on YouTube videos to make high voltage circuits. The most important part of the circuit is the mini-high voltage transformer which is difficult to find if not because of the fly swatter device. Apart from that there are high voltage ceramic mylar capacitors which can be reused for another projects such as DIY voltage multiplier, Tesla coil circuit, taser (stun gun), etc.


  1. Hi sir, could u please tel me the specifications of the transformer?

    1. There is no printed specifications of the transformer because its written in Chinese.

      But you can refer to the inductance value of it by viewing this video: Howto identify high voltage and low voltage side of transformer