How those Electric Fly Swatters Work! Teardown and Schematic
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- Опубликовано: 7 сен 2024
- Edit: OMG - I actually just looked at the datasheet for that transistor again and noticed that they have the pinout backwards - it's ECB, so just swap the B & C in the schematic! lol
The hardware store was handing these cheap electric fly swatters out for free the other day with any purchase. Thought it might make a cool video to tear it apart and show the basic schematic and explain how it works.
Couple more details: that capacitor is a 0.330uF "I think" The transistor is an NPN with part number: 8050S. The diode looks like just a standard rectifier diode. Let me know if you'd like to see a deep dive on how the transformer works, thanks!
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I was wanting to know how the bug actually gets zapped and your video answered that! Bug has to touch both outer and the inner screens at the same time. Glad you showed how to safely test that by (safely) shorting it to produce the spark.
Yes. Please, make a deep dive. Performance, voltages, current consumption, etc.
haha, yea I actually just saw a related video to this one is some kid sticking his tongue in one of these! But yea, I'll keep this board on my desk and take that deep dive
Kevin Darrah Amazing video. If you go more in depth, can you compare this circuit with those toys that are meant for shocking people?
I agree
Interesting. I have several of the flies Waters gained over the years, and have noted that the earlier ones were up to 900 volts whereas the more recent ones are a paltry 300 or so. The higher voltage one causes a gratifyingly loud "pop" when intercepting a wayward moth or fly mid air:. Whereas the lower voltage ones merely kill the flying beastie, without further drama. I decided to pump up the voltage of the lesser ones, but I can see that I need to put in more study before messing with it.
Thank you!
Yes please to a Deep dive. I find these inductor oscillators fascinating :)
Yes, A further operation video is needed. Thank you.
Hi Kevin... yes, go for the deep dive. I would like to understand how this works in detail.
Bigclive will be proud of you...
😂yea
😂yea
3m36s "I've never seen anything like this before"
3m43s "I've seen this arrangement before"
Is the high voltage causing memory lapses or something? 😂
lol, probably
😂 😂 😂 😂
Yes dive deep! also, make your own custom led cube bug zapper. use uv leds to attract them and when they land on it ZAP!
Yeah do the deep dive. Like to see how it performs.
Yes please - the deep dive with the oscilloscope sounds very interesting.
Remove the resistor over the capacitor, for more zap-goodness. :D
(Beware it will keep charge after the button is removed, my ex-wife learned)
ha! was thinking about that
Just let the fly be your 'bleeder' resistor :P
Thank you Kevin for this very interesting video. Question for you: when I push the button (and charge up) on my fly swatter in a pitch-black room, I see dozens of little points of light all over the inner grate, I imagine in the same spots where an insect has been killed (but I can't verify this).
I don't see any arcs, so what exactly is causing the grate to glow like that?
could you have gotten the transistor pinout wrong, if B and C was swapped the 470R would limit base current
thought about that, but the datasheet shows EBC, so all seems right? I think I'll pull the transistor out though and check... wonder if they used some variant of it that swaps BC
hahaha, OMG I just pulled the datasheet again, and sure enough the BC pins are indeed swapped!!! even for a TO-92 package! that's pretty weird. Funny thing was that the SOT-23 pack shows EBC... guess that's all I saw when skimming through it
Lasse Langwadt Christensen Not only the base current, it gets the circuit oscillating... First there will be current flowing from B to E. That will turn the transistor on and due to ohms law all current will flow through the other coil (C to E) turning the bjt off again. As soon as the bjt is off the currents only path is from B to E. Thats roughly what gets the primary side ocillating. Could be that windings of the coil are in reverse directions so Ac is induced to the sec side(wouldnt make sense with the diode) or their same direction and its just to get as much power used as possible. Even it looks pretty similar like a Joule Thief im pretty sure it isnt one. If im wrong at any point pls let me know.
yes. please make a deep dive video of this circuit. thanks in advance.
Definitely want to hear MORE!!!!
How would you rewire it to charge the center and cut out the outside cage?
This is my question as well. This zapper doesn't work well with small fruit bugs as it can't touch both inside and outside at the same time. I have removed the outer nets, but now center doesn't work; however, one outside wire zaps, but the other outside wire does not, so now it's all screwed up as I don't know anything about electricity. I tried messing around with outside wires touching the middle net (only one touching, or both touching) and nothing happens, so again, only one outside wire zaps, and the middle and the other outside wire still do not zap.
You need a different center screen that alternates positive and negative bars either horizontally or vertically. The Negs are all wired to one side of the output and the Positives wired to the other output. The critter completes the circuit. I believe there are at least two manufactures that produce these. Executioner being one and I cannot remember the other. name brand one. There are various knock off models of thes two.
Not having the outer grids lets you touch the shocking grid easily!
Why is it using high voltage instead of high current? After all, it's the current that kills.
I think its cus when the voltage find through the fly, its the low resistance of the fly's body that creates the high current(uneducated guess)
It is built to stun or kill small bugs not human. The amount of charge stored in the capacitor is just enough to not shock human if touches them accidentally. Even taser cannot be made with high current.
I have the same kind here but it runs on 2 d batteries and I also opened it up, it's high voltage capacitor has 12kv on it
+1 for deep dive!
yes, please do deep dive video!
Yep, I would find that very interesting. Also doing that across multiple of these devices since the circuitry differs quite a bit among them. And although I do understand some of them somewhat, I never understand all of them completely. Especially due to the transformers being used, I guess, if they're different than what you'd expect. I was thinking of winding my own, just to get some more voltage and current into the HV side.
Would love to see it.
There's another video on RUclips in which a guy just ordered a HV stungun module and hooked that up. It's nice but now we're starting to get these giant wasps (they're not really wasps but a different species) more power is needed in these things. One thing that bothers me with the factory default ones is that the bug often isn't killed completely when it is zapped using the standard circuitry. It suffers. Especially when the batteries start to get low.
So a 1 or 2 18650 battery version would be nice, stepping up the voltage and current when compared to the default circuitry. Current doesn't have to be upped much. Might get too dangerous too quickly, but every bit helps.
If the giant wasp gets killed instantly, that's the goal. And the stun gun module doesn't seem to do that all that well, consistently (I already used such a module too in one swatter that I have).
Cool thing about that is that small mosquitoes do get instantly vaporised. Which is why I have been satisfied using that for quite some time. However, as I said, now the large wasps (hoornaars) are here... something more feisty is needed.
So a deep dive would be highly appreciated.
Oh wauw... I see you are doing a lot of Arduino stuff. Cool. That's a subject I have been wanting to get started with for some time now. Might be a good summer to finally start with that.
Definitely will check your videos out!
Found a new channel to watch. Thank you for the great content.. Keep on keeping on.. Just subscribed...
Did you get the pinout on the transistor wrong? I guess base in on the end and collector in the middle (japan style). Then the resistor is on series with base?
Yeah I'm pretty sure he got it wrong.
I have one of these but it zaps when it wants to. Do you think it's the transistor? I know that generates the signal that powers everything so If I could find one in something and use it in the zapper.
I'd like to see a "hot rod" version of this item too as these things work on mosquitoes but not larger insects like hornets and beetles. I have two of these and one uses two C cells and one two AA cells.
Hey - I was wondering if you could make a video on how u made the led tester for the rgb cube... Im new to circuits and I can't find any video that explains how to make a rgb led tester ... I would really appreciate your help- thanks
how is 9v dc is given directly to the transformer. isn't contrary to the action principal of the transformer which needs ac or varying field. can u explain more about it?
I acquired a NAPA auto parts cock with a neon ring light on it. The neon driver power supply transformer burned out. I wonder if this power unit can drive the NAPA clocks neon tube?
Marty you have to get the flex capacitor
I think you got the transistor pinout wrong or the windings wrong. The resistor should definitely be in series with the base.
Can you show how to use a rodin coil please. I. Bought one and it has four screws on the side . I dont know what to do . I want to play music from my phone amplifier n function generator and cant set it up
Would it be possible to hard wire one of these? From say a USB wall charger?
yes, it will be interesting if you dive into it
From which store can i buy electric swatter in Australia?
If I have a swarm of small flies, will this take out a bunch in one swing or is it one zap and then needs to recharge or something?
It is quite effective at taking out multiple at a time but occasionally you need to bang on the rim a little to dislodge the fly carcasses unless you like the smell of charbroiled insect…
informative
There's a case in which a woman had applied alcohol to her legs as mosquito bite relief. A spark from her electric fly swatter ignited her legs, causing 15% burns and a 15 day stay in the hospital.
that is a flyback topology
I think he doesn’t know this is a flyback circuit and it works like that
exactly, actually the transistor base is limited by the R. once the transistor exceeds it's collector current it can support it'll put the T out of saturation , collector voltage rises and thus primary voltage is reduced. this will now reduce the base drive current and the T1 will cut off. now the cycle repeats. of course also the core saturation of the transformer will lead to a drop of inductance which increases the primary current even more, leading to the voltage rise at the collector and supports thus the shutdown procedure as described
I hold Flys on there till they smoke out their eyes.
#WengerOut
Cool!!!!! Fly Reverse Engineering!!