Inside Poundland's electric fly zapper bat. (with schematic) 

Mine's got about 1500v output, I replaced the cap with a 1µF 3kV (I think it was) and changed the resistor to 10Mohm, now it kills wasps with a nice loud bang...

Canadian here. They definitely sell this model in our dollar stores. It was preceded about ten years ago by the single layer, higher voltage version that Clive alluded to as a powered spanking bat. Those ones were able to burn wasps and etch fingers, they don't make them like that anymore.

I had an early version with the parallel sets of wires and no discharge resistor. It made for some interesting times. One night we were plagued by little flying specks clustering around a hallway light. Held it up next to the light, and it sounded like somebody was making popcorn.

For those who are curious, I stuck my finger between the outer grid and the inner grid one time. It's a very distinct sensation. More like a hard, blunt impact to the finger than the sensation of an electric shock. Hurts pretty good.

I am starting to think Clive makes his big money modding adult toys.

Kodak, once a photography powerhouse, now reduced to having its name slapped onto batteries in poundland fly swatters...

Easily the best bang for the buck I've received from Harbor Freight in recent years. Mine cost $3, uses D cells and has seen duty in the US, Japan and Korea. I love the smell of toasted mosquito in the mornings. The blood-filled ones give an especially satisfying zap....

"fly zapper" you mean "little brother zapper"?

I like older type you described, those things could really light someone up.I took a measurement with a fast acting Klein meter and it was reading very close to 1500V at the grid

Incredible explanation, amazing how a simple device is actually a bit complex...Great job...

"Current exchange rate". Would that be an electricians joke?

As soon as I saw the title I was preparing for the finger test. I was left disappointed Clive...

Great video and btw, I loved all of your behind the scenes videos at the Tattoo. Thank you so much for letting this old "Roady" live on the road some more through your videos. After 45 years on the road I finally called it time to pass it on to the younger ones, but I thank you my friend.

I need to buy one of these to make a static grass applicator. It's used for model railroads and dioramas and stuff. You apply glue to a modeled landscape surface, you touch a probe to the glue, and the other end is a cup with a metal grill. The cup is filled with dyed fibers. They are attracted between the grill and the glue, and stand on end, mimicking the appearance of standing grass. Some people make super cheap ones by hacking these swatters.

Back when they first appeared on the market in my state (NH-USA) they had D-cells. Had the horizontal lines vs the screen and the batteries made it feel substantial and was of higher quality (they were $20 or so then). Wasps & hornets would literally explode with the sound of a small caliber gunshot. Yes, you can find these in every junk...err... ChinaMart...errr... dollar/discount store still.

The guys at the club were quite pleased to discover that they could fit a 9V battery in the one they were playing with. :-)

You did do one a couple of years ago. When I had a look inside the current crop I was also impressed by the low component count.

630V capacitor just means it did not break down when 630V was applied for 30 seconds to a test sample of the metallised foil. The actual breakdown is generally around 800V, though many of them will actually survive 1000V for a few seconds, with only the occasional self healing internal flashover. Using on the mains however, instead of here in a very energy limited circuit, means that, during the flash over period, you get a very high current flow, and thus large areas of the foil vapourised. While on AC the self healing does isolate that particular area, as the arc does extinguish every half cycle, on DC you get a current flow, which in turn heats up more of the capacitor, and this arc area grows till it melts, catches fire and does a very bad imitation of a tea candle. There is a reason why proper mains rated Class X and Y capacitors are so much larger, as they both have a thicker foil, which has to be rated for 2.5kV, but also there are 2 larger value capacitors in series inside the foil wrap, so each half is 4 times the volume of the cheapie. Adds to the cost, along with those pesky certifications of samples of each batch by a testing lab, and in process testing. Rather different to the cheap one of "we tested one, so the next million or so should be fine" the dipped versions.

we have a pile of these in Finland at our summer cottage, we spend the first hour or so killing giant flies and mosquitos inside and around the cottage with them, wonderful invention

You BAD bear, using those things as spanking paddles. I was in tears when you decided to enlighten us to the alternative use of the fly zapper! :)

You can also remove the grid and frame and stick the wires out of the handle and zap people. But that would be a silly thing to do.

I have been looking for a video like this for weeks... and there you are!

I bought one of these from Harbor Freight and measured it at just a little over 1000V while holding the button. I did have the earlier variety as well with the simple alternating parallel wire arrangement, (which I fried while swatting a wasp), and it produced over 1500V.

Harbor Freight Tools in the USA sell a very, VERY nearly identical (on the outside anyway) version of these, for around $3. They've even had a "free with purchase" coupon on them in the past. I have one, but sadly, it uses the horrible "D" cell batteries, which cost a lot more than AAs, and many people don't keep on hand. Perhaps the makers chose to because of their large size, and ability thereby to move a lot of current quickly? Unfortunately, those D cells are heavy, and the battery chamber was so loose that swinging the swatter around (as one must do to strike a flying insect) often induced enough centrifugal force to compress the negative-contact spring, and make the positive tip of the D cell to come off the contact point. It would therefore interrupt the current, meaning if you swing it too hard [basically at all] then the damn thing gets no juice and doesn't work. I solved this in mine by making a conductive washer with an insulated ring around it, to take up the slack, but it makes it a real pain in the ass to change the batteries. That complaint aside, the darn thing killed dozens of yellowjackets for me last year. It does work, so long as the batteries stay in contact with their terminals. I've thought about clipping the connections to the D cells and putting an 18650 cell in there instead. Slightly higher voltage, and rechargeable. .

I heard of people replacing the AA's with a 9 volt. You should try that and see what happens...that is if you haven't already done it in some other video I haven't seen.

Very like what Harbor Freight here in the States used to occasionally have on sale for $2. Never took one of theirs apart, though, and I think that the meshes were more rudimentary.

Strewth! I remember your first video with one of these, years ago - it inspired me to have a dig into one of my own that was broken - I kept the circuit board for years! Eventually I had a go at building my own contraptions...

Been watching your videos ages ago, congratulations on your subbs mate. Keep up the good work pal

You once presented a chinese high voltage "stun gun" module. I watched that video and immediately thought of these bug zapper rackets. I always felt they could use a bit more oomph and the show factor could be more spectacular... Now figure what i did... Just replace the original module with that ebay-stun-module, you need to cut away some plastic ribs inside the grip panels for it to fit inside, use hot glue to hold it in place, resolder the battery box wires so that it can accept a single 14500 lithium battery to power the whole thing and voilà! "Stunning" results!

Thanks for all your videos been the best find in quarantine

Its a 3 coil version of a "Blocking Oscillator". Goes back to the tube days. I've built my own bug zapper powered off AC line voltage thru a voltage multiplier to ~2200V DC. The key is charging a 0.1uf (100nf) 3KV film cap. That works out to roughly a 1/4 Joule of energy stored. That energy gets dumped thru the bug. The resulting "steam explosion" (bugs innards are instantly boiled) totally vaporizes the bug. It wouldn't surprise me that the makers of these "dollar store" zappers are seriously exceeding the voltage rating of the caps. I've found that film caps can usually survive over twice their rated voltage for some time. Plenty good enough, for cheap toys like these. The caps will die eventually. But that maybe weeks, if not months, of intermittent use. A good experiment for those wanting to get into electrical engineering, is to hook up a film cap to 5x its rated voltage, and measure its leakage current. If doesn't fail in short order, keep the setup going for an extended period, (measuring at a regular interval) and see when the leakage finally climbs.

I know little to nothing about physics but I still come back to your videos

Found your channel researching electric lighters, can’t stop watching

Big Clive knows electronics like Ralphy knows whisky ☺️ the best breakdown of a circuit ☺️ your fun with the “ water purifier “ is also a winner ☺️☺️ great informative videos Clive ..Regards Peter

The early ones used to hold their charge (I assume no discharge resistor on the output) which was actually a lot more helpful for zapping the little winged buggers... I’ve also noticed a phenomenon where they appear to get really freaked out by the noise of them when the transformer circuitry is energised... doesn’t appear to happen when it’s held near them uncharged or charged but not energised

Nice and simple design 👍 Nice walkthrou Thanks for sharing 👍😀

Fun fact, modelrailroader as myself modify these to make static grass applicators, the static charge makes the grass stand up to make it more realistic! There is build videos on youtube.

I replaced the circuitry in mine with one of those high voltage generators/stun gun modules that you did a video on and replaced the batteries with an 18650 and micro USB charger😁 Let's just say the sparks are a little more interesting now lol.

I've seen the mains powered version of those, it's basically a capacitive dropper with a rechargeable battery, however it doesn’t have a charging lead, instead it has europlug prongs that pop out of the back and you use a deathdapter to plug it into the wall, I’d love to see one of those as well

Years ago my friend and I got a couple of these and had some fun inserting bigger capacitors into the circuit. With one large one, when the racket hit a fly the fly exploded.

They are 1100v. We took one apart at work last year. It gives you quite a jolt.

about 15 years ago they were just vertical bars with alternating polarity...much more effective and allowed some decent cooking of insects. also a guaranteed shock with the residual charge

I have that for a few years from Harbor Freight and it does a great job except the damn thing is yellow so the bugs see it coming due to their IR/NIR vision.

I've been meaning to get one of these to modify into a static grass applicator. This video will prove useful!

I've got two of these around in the house, one of this new finger zapping safe design and an older one. I must say I strongly prefer the "less safe" option as well, it'll zap the bugs more reliably. Also for some reason it actually works on small things like fruit flies while the new construction seems to leave them untouched most of the time (although maybe that could be adressed with a higher voltage?)

Bought a Zero In Bug Bat version of this from Aldi earlier this summer and dealing with fruit flies has never been easier or more fun. Different design electrically and the discharge resistor hadn't been fitted so on a low-humidity day you could get zapped a couple of minutes after use if you picked it up by the business end. Aldi didn't seem concerned and the manufacturers response was it was being redesigned so that made it OK.

The 2 pound version has voltage multipliers and a 2kv rated capacitor. Also rechargeable.

I measured the voltage of a similar zapper. The voltage was approx 1400 volt, but it varied quite a bit between each try (between 900 and more than 1500). That may have something to do with the fact that the output capacitor was only rated for 250 volt AC.

Pound land needs to put him on tv and make some fantastic advertisements!

I measured the voltage of mine a while back and it reached just over 900 volts. It has sent on their way, two tiny annoying fly's and one huge bluebottle. The bluebottle was a one hit kill. (marks kills on the side of the racket)

Shocking! Makes me want dig my coil out of the doomed project pile... That reminds me - if you're ever worried about if the laquer on a winding is damaged you can test by dipping the whole thing in salt water and testing for continuity with the ends.

I made some very strong ones in school back in the 80s we used can transistors and big . Real big transformers. Massive discharge and they ran on d batteries.

Looks identical to last year's model. I took one apart and used it as the driver for a home made Tesla coil.

Good video Clive

Not gonna lie Clive, probably one of your most terrifying thumbnails

I opened mine today to repair it, it has much more components than this one, both 220Vac wires were disconnected, due to cold solder connection. Now it works well.

Now, since I have seen this video I'm going to take mine apart and play with it! Hours and hours of pleasure, I mean fun! Thanks big Clive!

I've got an older version of one of these. Not sure where it came from. The circuit uses different values of components, but otherwise seems to be the same. It has a X2 330nF cap on the output rated at 275V. I measured the voltage across the grids at 840V!

Continuous usage not only overheats the transistor, it makes the flies smoke a bit, too!

I have the earlier (voltage multiplier) version of the unit here. A rating sticker on its handle claims it's 1.5KV, 1.5W. So unless the newer design has dropped the output a lot, that output capacitor is badly underated. Also the discharge resistor is probably rated at only 250V, so could well go open-circuit eventually.

A very popular item in the tropical areas of Asia for it's bug zapping qualities and may also be used on bar girls.

I had one when they first came out, instead of a grid the wires were all run in parallel... like a tennis racket with the cross strings removed. It seemed to be a bit easier to use because the bugs didn't have to go inside the grid.

I used to 'tune' these with a lithium cell (550mAh from vape) and a 1µF cap minus the discharge resistor..don't do it kids, but I gotta say it rips the insects apart pretty spectacularly

These are much more fun if you take out the circuit board and replace it with a $5 taser module from Amazon. They arc on the inside around the edge and make a good light show. Much more satisfying pop when you hit an insect.

A couple of years ago I bought a few of them at Harbor Freight in the US for about $2 each. They work great and give off such a nice satisfying snap and flash when I finally zap one of those annoying pesky house flies. Sometimes a few extras zaps to make sure I got it gives off a bit of smoke and the odor of toasted insect.

Finally i almost understood the *Schematic* cheers and thanks.

Yup there are ones that break when you wqve them. The one here has better side supports. I ad glue to thrm. You can buy them from Dollarama

That discharge resistor was 22 not 2.2 Mohm. Third band looks more blue than green to me.

we have several of these. They're awesome!

I got one of these after seeing your earlier video - it's great for annoying mosquitoes! You should get sponsorship from Poundland - for a pound 😁

I use mine to run filament LEDs in series, good enough for short bursts of light.

Could you measure the length of the spark? (tells a bit about the voltage -though not precise at all)

When I was at school I made a people zapper by winding a billion turn transformer for the HT and a smaller winding for the primary. I wound it all on an iron core. At one end I made a metal slug on a bit of old clock spring that would snap to the core when current flowed in the primary. I used a 4½v cycle lamp battery. I hooked up the primary winding supply in series with a pair of contacts driven by the metal slug and hey presto! a buzzer with an HT winding. The whole thing fitted into a small wooden box that amplified the buzzing sound. So satisfying. Much fun and pranks to be had. Rings of people in the playground holding hands zapped. Coins in the bottom of the toilet sink filled with water. Brave souls could just about stand the electricity through their hands in the water but the instant they touched the metal coins double zap! I kept the gubbins inside the box a secret for more mystery.

cool always wanted to own and open one up of these.... too late done now :) thanks Clive!

seems things have changed a little bit since we last saw this thing here.. see you in another 3 years little zapper!

I'm now thinking I could use something like this for some military triodes I bought to mess about with for the grid voltage.

thanks for the analysis good info,.i have seen those at HarborFreight for 4 $, now i want to take one apart,.lo.

Bought one of these. Definitely worth the £1 I paid for it. Mosquitoes are so much easier to catch and kill with these as the racket is quite large. However my unit doesn't seem to kill them, it just stuns them.

Last one of those I took apart had at least a two stage VM on the output giving a grid voltage of 1.5kV, that one you have, I can see that actually going over the 630V rating of that cap

i have the same one, i removed the resistor for louder sparks ^^

We have one and we love it. It works.

The old version with alternating polarity bars instead of multiple layers of wire was much better suited for spanking. 😉

Que interesante. Gracias por las explicaciones

7:37 this answer a question i hav had for a long time.. tnx m8!

Nice explanation of the circuit. Isn't that resistor at the output 22 megohm (red red blue)?

We have the same ones here in the US and you are correct, they only cost a dollar.

When I used to play with hydrogen / oxygen made from water, I used a modified bug zapper to ignite the gases in whatever container I was about to blow up. I had taken out the mesh and soldered longer wires to the high voltage wires so that I could stand behind cover. I had also replaced the AA batteries with a 9 V battery to up the voltage. The 9V battery even fit perfectly into the original housing after a bit of sanding.

I incorporated one of those into an actual wood spanking paddle 🤣🤣🤣🤣🤣 Split the wood length wise and made a channel for the wires and then got big round fabric rivets one side

I have a version with a bigger capacitor and more multiplier stages. I used it as a fluorescent tube battery operated ballast

I got one of those rechargeable ones.. it would be interesting to see their charging circuitry..

I actually use this mosquitos are a big problem here, but my version has a internal battery which you charge directly from 110v AC

That must be a fly-back system Clive, cos it is a fly bat

I got one of the old style zappers with just straight wires and i measured about 60 Volts.

I've got a taser module that I bought specifically for a super bug zapper project. It'll be powered by an 18650. One of these days I'll do it.

I measured mine at about 900 V (IIRC), using a chain of ten equal resistors connected by clip leads (because I couldn't find ones with a convenient ratio to use fewer, and also because I didn't want too much voltage across any one resistor), with the multimeter across one of them. It was the 'unsafe' kind with alternating-polarity wires, which I found more effective against flies than the 'safe' kind with three layers of mesh. That was back in 2017, I think. I bought it at the beginning of that summer, and later added a microwave oven capacitor (~0.7 µF @ 2 kV*) to it. Unfortunately, the racket got destroyed at the end of the summer when a chair rolled over it. I was going to build a new one (which would use the whole rated voltage of the bigger cap), but the flies, at least the ones big enough to bridge the wires, haven't been anywhere near as bad since then, so I haven't gotten around to it. *I just did a search for typical MOC ratings, and learned that you can greatly overvolt them (by ~6× in the reported experiment) and they'll still work for a while: stevehv.4hv.org/MOCs.htm

At 1:12 "It is held together with 5 screws ... which must have broken their hearts at the accounts dept" ... that cracked me up. I needed a good laugh. Cheers Clive :-).

Mine charges directly from the wall socket & has rechargeable battery inside. And it’ll fry any insects instantly that get stuck between the mesh. UK ones seems to be quite tame.

I hope your skin issue clears up soon Clive. I don't mind the gloves I have similar spots on my leg that have persisted for about 4 years with several different treatments. The steroid cream made it heal but made it heal too fast and it just flared back up again. I'm also sure that living in Florida has not helped with the heat issue for it.

Tut tut Clive, you know full well that Current doesn't flow at all. It's charge that flows and the current is a measure of that charge.

I like the gloves Clive. Touching the zappy thing with exposed fingers - explained well in 2:08 though. :)