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.
Hi Arup,
I am interested in your project. I would like to know whether their is any way to do this technique on my car. I mean when some one touch the metal part of the vehicle, will get a small electric shock . Is it dangerous.
regards
aswin
It's not that dangerous, but doing it in car, you'll risk many things. So, don't do it.
i want to attched five 12v moter in mosquito racket. So cn i able to do this.......pls help.
What? Why and how would you attach five 12V motor to this.
m making 3 idiot hellycop. So we need power to lift the helycop we cnt use battry it wil b heavy. We want to use mosquito racket circuit because it increase the power of battry. Pls help.
It increases the voltage and not increases the power of the battery.
I bought a mosquito raquet with additional LED connected to it working as torch light 3 days back.First day it gave gud results with mosquitoes dying with a spark.But now mosquitoes do stuck at the net but no spark comes out.WhOn touching the net with tester ,small amount of spark comes.But the torch light LED brightly glows.Please help me out.Please.Mosquotes are not dying with the bat.
Check battery voltage. If battery giving good voltage, check the output capacitors.
Same Problem Happens to me also,
1. How much level DC voltage have to given to the circuit for Spark, and
2. if Capacitor Faults means I have to change the Output Side capacitor Uh???
Please Reply
Yeah, you need to change output side capacitors.
Hi: I want to make a windows fence for mosquito (1.2mts x 1.5mts) ,i will use a cel charger 5v with power on/off,what material need for this projects? or only negative and positive connections using my cel cable into new net window. can you help me making a windows fence safetly.
thanks.
What will happen ,if man has touch the bat net when output getting.
A medium shock (not killer)
output voltage is the AC voltage or DC voltage ?
AC
hey bro i am using this circuit to make a tesla coil ... is there any way to increase output dc voltage without using a step up transformer again in this circuit????
If you feed it with 5 or 6 Volts DC (the circuit normally is planned for 3 Volts DC) you will obtain some thousand volts AC High frequency at the output. Voltage is enought for any Tesla coil project, but the current is very very low (But for Tesla coils is needed high voltages, not big currents).
Regards,
Dear arup i used new non rechargeable cells of 3v.....cheand checked.......problem remains the same...that means the out put capacitors are faulty.....just give me the specifications of output capacitors so that i can get it from market.
The values I saw in my circuit is written above in the drawing, however your one may have different value. If they are readable, use that values or use my values.
Dear friend,
First of all, thank you for your very interesting post informing about small flyback transformer based circuits used in mosquito (racquet) devices. I suppose there are small variations in this kind of circuits depending on the specific device (racquet).
My circuit is based on:
On the primary side: One 1K resistor, one PNP S8050 transistor, one led indication diode and a small resistor for control current in this led diode.
On the secondary side: one 101pF (3Kv) capacitor, 2 Diodes (I can’t see the model), one 0,1uF (1Kv) capacitor, and finally 1MOhm resistor for capacitor discharging after switch – off the device (This resistor is a safety resistor).
My circuit when I feed it with different DC voltage levels always oscillates at 15 or 16 KHz with nothing connect to the secondary final output and some thousand volts (depending on DC voltage level at primary).
When I connect my flyback circuit (Supplier) to my project circuit (customer) it oscillates at a frequency of about 16000Hz. For my project I need a High Voltage power supply of more than 20KHz or 25KHz, but I can’t find the way to increase frequency more and more.
I tried some ways:
I increased the 1K resistor at the primary up to 10K – 15K, but only small gain in frequency and a big loss of (current transistor) so at the end, transistor is blocked and output voltage lost.
I placed 3 101pF in series instead only one (that means to have 33pF), a small gain in frequency but less output current for each capacitor added.
Final 0,1uF (1Kv) capacitor connect in series with a new one (that means 0,05uF), no effect observed.
So, please, could you explain me how to increase the working frequency of my HV power supply (mosquito racquet circuit) from 15 – 16 KHz to ranges and forces it to oscillate up to 25 or 30 KHz?
Thank you very much.
In that case, I guess you can't increase the frequency unless you're using a separate oscillator for the driver transistor. In these fly-back applications, the frequency is determined by the driver transformer and the capacitor between the base and emitter of the transistor. If your one posses a capacitor between the B & E of the transistor, then decrease it's value. Otherwise there is no hope.
BTW, S8050 is a NPN transistor and not PNP.
Cheers,
hi arup, the common problem in these rackets is after some days it will not get spark or very low intensity psark which will not kill mosquitos.
what will be the problem?
Common problem: Poor battery performance
HI, My mosquito bat was discharging very slightly, i seems to be anything repair in the component in the above circuit, what i have to change or what actually happened...... Guide Me
HI.
I have problems with possums eating my plants & sprays haven't stopped them. I want to convert one of these mosquito bats to a smallish electric fence to deter them.
I would need to have about 6-8m (18-24 feet) of wire to cover the area. Will the standard electronics cope & be effective or will I need to beef up the circuit keeping in mind I want to give them a good solid shock but not fatal.
Thanks.
Al
The shock of this circuit may not be good because it will probably burn few hair(fur) and do nothing but make them run in fear.
That's exactly what I want. I want them to run in fear & leave the fruit trees alone.
Will the circuit be sufficient to use as a small animal deterrent with fence wires around 6m (20 feet) long or will there be a lack of power?
Thanks.
hai. Im from cochin. I want to fix my mosquito racket. It worked fine for 1 day and now it wont kill mosquito. It produces little spark when i touch it with a screw driver. There is no hissing sound now when operating, but it was there when i bought it. I changed the rechargable battery. But it didn't help. If the problem is with the transformer or driving transistor, what is the rating. Can u please tell me..
The rating differs from unit to unit however you can take an example from above circuit.
BRO.. MY MOSQUITO RACKET HAS BEEN DEAD AND I HAVE TO CHANGE THE BATTERY INSIDE IT.. IS IT USING BATTERY OR CAPACITOR?? PLEASSE REPLY SOON
There's battery inside it.
2xAA rechargeable batteries will do the job.