Build this Mosquito Bat without Battery

This simple homemade mosquito swatter bat neither requires a circuit nor a battery for the operation. The entire design works using a single high voltage capacitor and through quick charging from mains AC socket. (Designed by me)


In a few of my earlier posts I have discussed how to make mosquito zappers using the conventional high voltage circuits, and using chargeable battery for generating the high voltages.

Such swatter bats work great but they have some serious drawbacks.

These units use a fairly complex circuit which require a calculated inductor and a switching circuit. The second complex thing in the design is the bat mesh which cannot be hand made and require special equipment and tools for the assembly.

Moreover the battery used with these bats being cheap degrade at a faster pace and finally become useless, requiring replacement, which usually become difficult for a layman user.

All these complexities finally compel the user to dump the bat in a scrapyard and go for a new one.

The design explained in this post is quite unique, and is free from all the above downsides, and complexities.

The main features of this battery-less mosquito bat can be understood from the following points:

1) The bat mesh uses a PCB and solderable wire assembly which makes it easier to construct by any user having ordinary technical skills.

2) The bat uses a single high voltage capacitor for charging the mesh, and gets rid of the complex switching circuitry.

3) The high capacitor can be charged directly from the AC mains, and therefore the design does not have to depend on costly NiCd or Li-ion battery, and long charging periods.

You might have by now understood the unique features of this bat, let's move ahead and see how simply this mosquiito bat without battery may be constructed by anybody at home.

How the Bat Mesh is Designed

Referring to the figure below, which looks quite self-explanatory, we can understand the details from the following points:

  1. The green base background is actually a PCB, with copper tracks etched on it, shown in orange.

  2. The PCB is elliptical in shape with a large central cut out, and a couple of horizontal ribs to enforce better rigidity to the PCB frame.

  3. The grey lines are tinned copper wires, around 0.5mm in thickness, tightly stretched and soldered end to end across the indicated copper tracks. The wires are alternately arranged and connected with the respective power line tracks, on either side of the layout.

  4. The wires are also soldered in between across the two central ribs to reinforce them with increased rigidity and firmness.

Designing Swatter Bat without a Battery

That's it, the bat mesh is now ready.

Now let's learn how the stem or the handle of the bat is designed, and the electrical specification details in the following section:

The next image below details the integration of the bat mesh with the handle and the electrical wiring which needs to be done within the internal space of the handle:

From the images above we can identify the following connection and wiring details:

  1. The handle upper and lower assemblies preferably needs to be a push-fit type, with corresponding male/female AC pins, such that when the two sections are push-locked, the pins also get pluggedin with each other.

  2.  The lower section of the handle can be seen enclosed with a 10uF/400V capacitor (Non-polar), whoseterminals are electrically wired with the external plug pins.

  3. This section of the handle plays a twin role, first it allows detachment from the bat and plugging into your home mains socket for a 1 second quick charging, and next, the same plug pins are allowed to be inserted back into the upper bat section for arming the bat mesh net.

The following figure shows how the lower handle section needs to be detached and plugged to an AC socket for charging the internal 10uF capacitor, (for a 1 second charging).

How the Swatter Bat Works without a Circuit or a Battery

Through the above discussion, you might have already understood the concept, where a high value charged capacitor is used for electrifying the bat mesh and electrocuting the bugs or mosquitoes flying between the parallel wires of the bat net.

That looks pretty simple and doesn't need much of an explanation.

Some Technical Necessities

The proposed design uses a single capacitor for the charging the mesh, which implies that the voltage level is significantly reduced across the net wires, as compared to the conventional bat designs.

Therefore in order to make the design effective, it is important to keep the wires soldered on the bat PCB to be not more than 0.8mm away from each other.

Anything above this distance might allow our tiny friends to dodge away the fence, and to safety.


Anything that comes easy invariably possesses some hidden drawbacks and dangers. Here too, although the bat eletrocutor design looks straightforward, the mesh network is held completely exposed to an accidental human touch.

Therefore, once the charged capacitor is hooked-up with the bat mesh, be very cautioned not to allow any of your body part to come in contact with the bat mesh.

Otherwise that could cause a painful memorable jolt to your body. Since the shock is from a capacitor, it won't be lethal, nevertheless it could be quite nasty.

Need Help? Please send your queries through Comments for quick replies! And please Bookmark my site :)


Soumen said…
Sir....good morning....i found a old 'SONOSTAR' 4ohm 30w audio amplifier in my home...the transformer is missing...It has everything else...4 daiod probably 1N4004 and capacitor 1000mF 35v ...and in the main circuit there is two 2N3055 transistor... no IC...sir plzzz say which transforma can i use or input dc voltage.......thanks in advice...
Swag said…
Ho Soumen, you can initially try a 0-12/5 amp transformer, and check the response
jindro said…
Sir can I use old mosquito bat, and remove the old pcb
Swag said…
Jindro, the mesh wire spacing in conventional bats may not suit the above concept, because in the above concept the distance should not be more than 1mm between the mesh wires, whereas in conventional bats the distance could be much higher than this.

nevertheless you can give it a try...
Kesav.N said…
Hai sir....

I have few doubts sir...

I have 12v dc 500ma adapter..
By using lm7806 i got output 6 to 6.10v..
How much current will come in output..500ma or it will decrease or increase...

Sir i need 6v 250ma output sir...
By using input 12v 500ma sir..
Pls give me any circuit sir
Swag said…
Hi Kesav,
the output will be 500mA maximum current, however it is the load which will decide how much current to draw, if you connect a 6V 250mA load, then the current consumed by the load will be 250mA only, it will never be 500mA

for more info you can read this article

however if you strictly want to limit the current to 250mA, then you can use an LM338 circuit at the output of 7806, as shown here
Kesav.N said…
Thank u sir....

4v lead acid battery charger circuit with auto cutoff or normal i need sir...pls share it sir
Swag said…
all batteries require an auto-cut at full charge...for 4V battery you can use the following concept
raph said…
It's been a while I've not been here this is why my message arrives quite late. I like to navigate on your site where I find usefull tips and ideas as well. Regarding the mosquitos bat, if the capacitor is fully charged, it can deliver (theorically) almost 400W, which is enough to stop some human hearts I think. Also, you must trust your capacitor manufacturer to connect it directly to mains, I know there shouldn't be any problem, but imagine someone doing this with a capacitor coming from a cheap chinese device. You already write it but the cap must be non polarized and 400V at least.
Swag said…
I am glad you are back and liking my site!

As for the above concept, if the user finds the capacitor value to be on a little dangerous side, the person can always adjust it by adding a small value resistor in series with the net mesh copper layout circuit,

The resistor can be selected such that the output is sufficient to kill a mosquito but not so dangerous even to the folks with weakest of hearts.

If the capacitor is low quality it will explode, this explosion will not be at a level that can harm anybody, that said it is the user's responsibility to make sure he gets the parts from reliable sources.
Abbey said…
Well done, from what I see are there more simpler way to explain your diagram that is more explain. As a hobbits. to some one who does not know much about electronic. where can you advice I start
Abbey said…
what i mean, i know little about electonics and it amaze me how you put things together. how best can I benefit from your works. to understand and grow like you what basic do i need to know?
Abbey said…
please teach me in a layman language. how to get ride of walgecko
Swag said…
you are welcome! You can start by learning how the basic components like transistors, resistors and capacitors work in electronic circuits...
Swag said…
you will have to go a long way by learning the basic circuits first step by step, you can start with the transistor circuits and try to grasp how the various configurations are set up to function.
Swag said…
they are good, don't drive them away
Lawal Ayobami said…
hello sir,
how long does the fully charged capacitor operate with the bat before recharging? mins, hours or days?
Swag said…
Hello Lawal, it will depend how many mosquitoes you have killed? otherwise it can last for many days, not sure about the exact period....
Abbey said…
please I want you to help design a universal bottle cap fragrance sprayer that can work with the size of a bottle mouth that can spray at interval. How to design auto spray for fragrance.
Swag said…
sorry I cannot help with the mechanical details of the sprayer, that you will have to purchase readymade

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