There are these types of mosquito killer racket are easily available in market at some 150 rupees.
This consist an electric fence in the bat portion which has 5000-10,000 volts passing through them. This is not only mosquito repellent, it’s insect zapper. When a mosquito gets in contact the high voltage  burns it. The inner circuit consists of battery, a charging unit, and a HV inverter circuit, which I’m going to describe here.

Coil turns will be as described in text and not the one indicated in this tmage.

The circuit consists of a flyback topology transformer driven by a general NPN transistor 2SD965. The feedback coil of transformer is of 10 turns, the primary is of 40 turns and the output or secondary coil is of 450 turns. When this circuit is run by 3Volts, the transformer generates about 2000-4000 volts at zero load, and the output is then coupled 3 times by using 3 IN4007 diodes and suitable capacitors, thus reaching our need of 5000-10,000 volts.

Note:  All diodes used in circuit are IN4007 diode, The transistor is 2SD965, and can’t be replaced by BC548, The transformer should be ferrite core.

Below an actual circuit board found in mosquito zapper rackets.

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208 Comments

  1. Need help with capacitance charger circuit, why am i getting 230 volts at bridge rectifier, bleeder capacitor 105k/400v resistor 390k.

  2. instead of batteries which are not availble to replace can a mobile charger or something else be used

      1. When I bytes the racket there was a rechargeable batter , which type of battery it . I can see two holes , which means we can refill it with some liquid , which liquid should I use to recharge those batteries.

    1. As a capacitor is discharged, output current could be high enough to kill a person. Assuming around 100mA at it’s peak, for a very short duration.

  3. 1) I need inner / outer wire 1.5 ‘ to 4′ size or 2′ to 4′ size from where can I get and specification.
    2) I need shock proof cover to fit 2′ to 4’ size ( Outer cover – plastic: similar used in racket killer ).
    3) What power battery is used in racket (12w ) ?
    4) can we get ready power circuit used in racket killer ?
    please provide the reliable manufacturers or whole sellers name add and contact .

  4. I am a farmers and want to make insect trapper using solar light , florescent lamp. I want to know the what is that wire called and how the circuit is build . Like we use in mosquito killer at home.
    what is the specification of the wire and diode require to flow the current

  5. dear sir , i want to design transformer with higher current and voltage,So i need your help in deciding transformer specification such turns,core,inductance…..

  6. Dear sir i want design the mosquito zapper as per my specification, so can you please give me the calculations regarding transformers design???? If you can, it would be great help for me

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