A design method for electronic mosquito killing circuit

The electronic mosquito killing circuit is composed of a high-frequency oscillation circuit, a triple voltage rectifier circuit, a high-voltage electric shock screen, etc. The circuit diagram is as follows:

When the power switch SA is pressed, the high-frequency oscillator composed of the transistor VT1 and the step-up transformer T is energized to work, changing the 3V DC power into a high-frequency alternating current of about 18kHz, which is boosted to about 500V by T, and then passes through three 1N4007 The triple voltage rectifier circuit composed of diodes and capacitors C1 ~ C3 is raised to about 1500V and added to a special metal mesh. When mosquitoes and flies touch the metal mesh, high voltage will be discharged through the insect body, killing the mosquitoes.

In the circuit, the light-emitting diode LED and the current-limiting resistor R1 form an indicator circuit, which is used to indicate the on-off status of the circuit and display the consumption of battery energy. The resistance value of R1 can be adjusted according to the actual LED current.

Component selection

The transistor VT1 is a 2N5609 silicon NPN medium-power transistor, which can also be replaced by commonly used transistors such as 8050 and 9013. The LED uses a φ3mm red light-emitting diode, and the three rectifier diodes use 1N4007 silicon rectifier diodes. R1～R3 all use RTX-1/8W carbon film resistors. C1~C3 all use CL11-630V type polyester capacitors.

The high-frequency transformer T must be homemade: use a 2E19 ferrite core and matching plastic skeleton. L1 is wound with 22 turns of φ0.22mm enameled wire, L2 is wound with 8 turns of the same number of wires, and L3 is wound with about 1400 turns of φ0.08mm enameled wire. Note that the black dots in the picture are the ends with the same name. Wind the windings in order, and place one or two layers of thin insulating paper between the windings.

You can design the specific usage of this electronic mosquito killer. For example, the electric shock net is put on a badminton racket, and the circuit is placed in the handle of the racket to become an electronic mosquito and fly swatter; or the electric shock net is made and placed flat on a dish, and the bait that mosquitoes and flies like is placed in the dish. Mosquitoes and flies are attracted to the electric shock net and will be killed.