These devices have been around for a while. They're basically a bat/racket/racquet that has an electrified grid that zaps bugs when they pass near it. The units tend to run from two AA cells and have a very simple step-up circuit involving an initial transformer stage and then a short multiplier to charge the main capacitor to a high voltage. When an insect makes contact with two layers of the grid the capacitor discharges through it.
Two things surprised me about this design. the location of the NPN transistor in the transformer circuit and the unusual two section rectifier/multiplier that charges the main capacitor. Particularly unusual is the choice of different capacitor values for the two lower stages of the multiplier. I would guess it might be to optimise efficiency or to keep the cost to the minimum.
The older bats used to have open rows of alternate polarity wires, but the newer ones use a sandwich of three meshes and insulating layers. I would guess it's actually a lot easier to make them this way, and also results in a slightly safer and stronger bat.
The boost circuit isn't really designed for continuous operation, although the switching transistor only reached a temperature of 50C in normal use.
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16 thoughts on “Inside a bug zapper racket / racquet , with schematic.”
  1. Avataaar/Circle Created with python_avatars Acting Flight says:

    I got various ones as well, but i got a odder one that i don't know if it is normal or not.
    Aldi was selling some under the Gardenline brand. Model 47168

    It seems to work as it should since once it pops gnats with a loud pop and i managed to kill flies with it.
    But the odd thing? It creates Ozone.
    It's making this bleachy smell when i keep it active that's reminiscent of ozone which confuses the hell out of me.

  2. Avataaar/Circle Created with python_avatars Sebastian Kusyk says:

    In my one, transistor's base is connected to batteries without any resistor, just through the feedback winding. However, the base is also connected (parallel) to some other winding probably from the secondary side in series with resistor.

  3. Avataaar/Circle Created with python_avatars Pete VanDemark says:

    Why not eliminate the discharge resistors to give the transistor light duty? Pump up the 2kV capacitor and let it ride. Push the button once in a while to replace the cap leakage. Just keep your pinkies out of the mesh!

  4. Avataaar/Circle Created with python_avatars M F says:

    Great video! This is the video that gained me as a new sub for you about three years ago. Well, I'm back here again this morning to ask you to please consider doing a "Part 2" to this zapper video, if you have the time, of course.
    One thing I would definitely be interested in seeing is how one would go about checking the voltage output on any given unit, using a multimeter (if that's possible to do, without torching the average budget meter).
    And the second thing (of course!), would be to see you mod one of these to increase it's effective "dispatching" power. Thanks for any reply! 👍

  5. Avataaar/Circle Created with python_avatars Andrew Lee says:

    I've purchased maybe 5 of these. They work great in the beginning but after a while, the zap is just not strong enough to zap the insects that fly into the mesh. Battery is good. The on light is lit when the button is pressed. When I hit the inner mesh, it sparks but it just stops zapping bugs. Any ideas??? I would love to be able to fix rather than having to purchase new ones.

  6. Avataaar/Circle Created with python_avatars Not Expat Joe says:

    Throw the racket away, add a couple of brad nails and these make an excellent party zapper.

  7. Avataaar/Circle Created with python_avatars fabiuh991 says:

    Well, got one yesterday and had no AA batteries available so I hooked it to a 5v psu for test purpose and it seemed 5v was too high for the circuit to function continously

  8. Avataaar/Circle Created with python_avatars Kaj Kasket says:

    I have replaced the two AA with a 18650, the extra boost makes a mosquito disappear completely. 😁

  9. Avataaar/Circle Created with python_avatars GetCarterCarPark says:

    I had one of the earlier versions with individual high voltage grid wires. It didn't last long, after swatting a very large bluebottle fly and I clipped the wall with the racket and all the individual grid wires came lose and fell out. Bluebottle fly one, bug zapper nil! I was never any good at racket sports either…..

    I found if you use rechargeable cells it kills the bug zapper, but it is OK to use alkaline cells, I guess it's down to the internal resistance of the cells, alkaline cells having a higher internal resistance than NiMh cells, and your average bench PSU.

    I'm on to my 4th Bug Zapper, I also found that if you zap one of the larger bugs (larger than a UK miggie) you will find that the bug zapper only stuns the bug, you have to be quick to retrieve the stunned bug and dispose of/dispatch it before it wakes up and plays merry hell with you for zapping it!

    K Watt.

  10. Avataaar/Circle Created with python_avatars Landrew0 says:

    I've got one wired up to 4.5V continuous. It's slightly warm after running it for a few hours. It makes a louder snap than before with 3V from batteries.. I've got it positioned over a fruit fly trap to kill them all as they try to go in.

  11. Avataaar/Circle Created with python_avatars Tom Cee says:

    Centigrade? I didn’t think you were that old.👨🏼‍🏫😇

  12. Avataaar/Circle Created with python_avatars Tom Cee says:

    Though some of us Americans use the K , I refer racquet.

  13. Avataaar/Circle Created with python_avatars xephorce says:

    I am about to turn one of these into a static grass applicator. trying to be cheap. My first one was a failure but I think I got some non functioning parts from china so ya i should have know. but I seen some vids of people doing this so I am gonna try. about the transistor getting hot from continual use, what do u suggest as a replacement for it?

  14. Avataaar/Circle Created with python_avatars Fizzy Plazmuh says:

    We have similar versions in the U.S. and I rip the racquet off and mount contacts in the end and just plug them in when I need HV sources for plasma displays and general tinkering with. Also got tired of wee batteries going dead so I installed a fat 18650 rechargeable in the handle. Also installed a proper power switch so I could stop stunning myself. And thank you for doing such wonderful videos. Your efforts and warnings will likely save me, er… delay my eventual death by electrocution. If the isotopes don't do me in first. Good thing about being an old fart. Cancer has no teeth as a threat anymore.

  15. Avataaar/Circle Created with python_avatars Muppetpaster says:

    I have the alternating(grillstyle) one…..my little niece grabbed it to play the guitar on…..Boy oh boy did we have a laugh…..as she actuated the switch on accident while strumming along with some music…..She now has the greatest respect for the thing……lol….

  16. Avataaar/Circle Created with python_avatars cambodianexpress says:

    If you're looking on how to soup these up to be more lethal on bugs like I was… this is the wrong channel. He just discusses how they work.

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