Where can I find circuit for electronic rat trap? - Page 1
Forum section: electronics / beginners

author: Greorge
author_rank: Regular Contributor
timestamp: June 03, 2015, 11:52:22 am
content: I noticed that some outlets sell Electronic Rat Traps, but I cannot find information on how to build one.Could somebody help me to find circuit for the device?

author: Greorge
author_rank: Regular Contributor
timestamp: June 15, 2015, 12:11:03 am
content: Could somebody help me to make one?

author: nickn4
author_rank: Contributor
timestamp: June 15, 2015, 12:17:24 am
content: google is a nice place to start.https://www.google.nl/search?biw=1920&bih=955&tbm=isch&sa=1&q=electronic+rat+trap+circuit&oq=electronic+rat+trap+circuit&gs_l=img.3..0.57512.60874.0.61364.8.3.0.5.5.0.60.164.3.3.0....0...1c.1.64.img..0.8.172.j0HKsBcBXgM

author: rs20
author_rank: Super Contributor
timestamp: June 15, 2015, 12:34:47 am
content: Just be careful with this sort of thing, or else you'll apply 8000 volts to yourself and to quote some of the promotional literature, "ensure a quick, humane death".

author: Greorge
author_rank: Regular Contributor
timestamp: June 15, 2015, 12:37:50 am
content: I searched before my first post, but being beginner, I did not find solution clear enough to be on a safe side.

author: Richard Crowley
author_rank: Super Contributor
timestamp: June 15, 2015, 12:42:30 am
content: Please reveal exactly what you mean by "electronic"?Do you mean something mechanical that is triggered electronically?Do you mean something that kills the vermin electronically?Do you mean something that repels the pests?A URL reference to what kind of gadget you are talking about would help the conversation along.And URL references to what you found (and why you found them questionable) would also be helpful.

author: nickn4
author_rank: Contributor
timestamp: June 15, 2015, 12:43:45 am
content: Quote from: Greorge on June 15, 2015, 12:37:50 amif you dont know what your doing, why dont you just buy the consumer's version?

author: rs20
author_rank: Super Contributor
timestamp: June 15, 2015, 12:47:53 am
content: -- Assuming you're referring to a rat trap that uses electricity to kill --Yeah, I think you should start by building some boost converters that operated at safe voltages (e.g. a boost convert from 5V USB up to 12 or 24V), and get lots of experience with that. Then you'llmaybe(not really) have enough experience to safely work with 8000V, and you'll be knowledgeable enough to understand the circuits on Google. Come back later when you have a proposed circuit in mind; you have to understand that's it's near-immoral for us to hand you circuit diagrams that generate 8000V when you've said yourself that you don't understand them, let alone know how to safely test and debug them.Also watch this video through and see how much trouble these people go through to "safely" deal with 5000V, which is less than a rat trap:

author: nickn4
author_rank: Contributor
timestamp: June 15, 2015, 12:50:18 am
content: Quoteand just to be save here, i dont want to assume anything..You are going to use it for just rat's right?nick

author: Greorge
author_rank: Regular Contributor
timestamp: June 15, 2015, 12:52:21 am
content: To buy one is an option.But have couple of identical Capacitors from ex 240V electric mower starter arrangement and thought that can use them instead of just putting them in the box for later.Do not think that rats need 8000V to die.

author: rs20
author_rank: Super Contributor
timestamp: June 15, 2015, 01:01:36 am
content: The three stated voltages of rat traps I can find in a Google search is 8kV, 8.5kV, and 9kV. True that normal mains electricitymightkill a rat, but perhaps doing it reliably, repeatably and humanely* is a different story.* To be fair, with crushing/slow starvation of a normal mousetrap being our benchmark, there's a pretty low bar here.

author: nickn4
author_rank: Contributor
timestamp: June 15, 2015, 01:05:45 am
content: Quotesoo true xDQuotei found out some of the consumer ones are powered from 4 c battries. so i dont think a rat will die from the low volts in junction with the low current. one of them needs to up alot..

author: Richard Crowley
author_rank: Super Contributor
timestamp: June 15, 2015, 01:07:24 am
content: Quote from: nickn4 on June 15, 2015, 01:05:45 amClearly, they are using an interter circuit to boost the voltage to several KV.Not unlike the Xenon flash in your camera.

author: Greorge
author_rank: Regular Contributor
timestamp: June 16, 2015, 10:33:07 pm
content: Did anybody here was successful to make something like that and could share circuit and list of components?

author: Andy Watson
author_rank: Super Contributor
timestamp: June 16, 2015, 10:50:58 pm
content: Quote from: Greorge on June 15, 2015, 12:52:21 amNeither do humans. Without appropriate knowledge and experience of dealing with high voltage you are more than likely to be the trap's first victim.

author: Greorge
author_rank: Regular Contributor
timestamp: June 18, 2015, 11:00:53 am
content: Would I have better luck asking for plans for electronic Fly Zapper?

author: nickn4
author_rank: Contributor
timestamp: June 18, 2015, 05:02:52 pm
content: Quote from: Greorge on June 18, 2015, 11:00:53 amthis seriously concerns me about the purpose of what you are trying to build.by saying this you showed us the high voltage schematic is not meant for extermination of rats...just so you know,we don't want to be involvedin helping you make some kind of Tazer..please stop

author: Zero999
author_rank: Super Contributor
timestamp: June 18, 2015, 08:27:47 pm
content: The circuit will be pretty similar to a stun gun but may deliver a larger pulse of energy to ensure a humane kill.For educational purposes only.The two most common ways of doing this both involve a flyback transformer to generate a high voltage.Here's the simplist way to do this with a blocking oscillator:http://www.powerlabs.org/flybackdriver.htmUnfortunately, it's difficult to achieve such a large increase in voltage in one stage so either one of the following are used after the flyback circuit:1) A voltage multiplierThe one in the schematic above uses a Royer converter to drive the flyback transformer to generate a sinewave. The voltage multiplier circuit charges the capacitors in parallel and they're connected in series to the output. It produces a DC voltage. If the capacitors are never allowed to charge, the current will be tiny and will probably not be high enough to ensure death.http://www.hardhack.org.au/book/export/html/1042) Another flyback transformer stage:In the schematic above, the first flyback oscillator works by cutting the current to the transformer when the current exceeds the value set by the 75mOhm resistor and the BJTs base voltage. The second flyback is driven by a relaxation oscillator which fires the SCR every time the 2.2µF capacitor charges up enough to cause the neon lamp in series with the SCR's gate to turn on. It produces high voltage pulses.http://danyk.cz/paral_en.htmlThere is much more to this than just knowing the schematics. Building a high voltage circuit is difficult because careful attention needs to be paid to the layout and to insulate everything properly, otherwise it will all arc over.

author: Greorge
author_rank: Regular Contributor
timestamp: June 19, 2015, 02:43:24 am
content: Thought Police, you stop it !I want to make electronic mouse trap that is capable of taking out rats too.Hero999, thank you for your post.In a meantime watched video where UK fellow connected 10 transformers and got up to about 1000V, but arrangement looked bit strange.

author: helius
author_rank: Super Contributor
timestamp: June 19, 2015, 04:19:00 am
content: You expected the thought police, but what you got ishttp://www.youtu.be/0359hSerDeE

author: Simon
author_rank: Unknown
timestamp: June 19, 2015, 06:02:38 am
content: Quote from: Greorge on June 15, 2015, 12:37:50 amthen you have just ruled yourself out of making one. It's not only your own safety to consider but anyone who may happen on your device and not know it's dangerous

author: Greorge
author_rank: Regular Contributor
timestamp: June 19, 2015, 09:47:52 am
content: Not sure if this Forum should be about what cannot be done, but how can one argue with Simon

author: Simon
author_rank: Unknown
timestamp: June 19, 2015, 10:14:46 am
content: Quote from: Greorge on June 19, 2015, 09:47:52 amThere are times. You say your a beginner and don't have a clue how to start. This is a bad recipe for creating something that uses high voltage to cause harm under controlled conditions. At least do some high voltage work on stuff that is not meant to cause harm first to give you a firm footing in HV design and then look at this sort of project. If this is something you can get off the shelf then get it off the shelf, it will have already been tested and you won't be liable for any problems it causes under normal operation.

author: Greorge
author_rank: Regular Contributor
timestamp: June 19, 2015, 10:59:38 am
content: OK

author: Chris Wilson
author_rank: Super Contributor
timestamp: June 19, 2015, 01:30:07 pm
content: I gave up on electronic killers, they only get one or two rats. I made a fairly large wire cage, with mesh too small for rats to escape, with a drop down shutter. Inside I put a thin board, suspended on a hinge one end, and the other supported by a spring. Put grain in it, when enough rats are in it their weight overcomes the spring and the floor drops a few mm. This closes a microswitch and a small accumulator triggers a solenoid and the gate drops. You are left with a cage with several (the most I caught in one go was ten) rats in it. You can then dispose of them. Safe, has a simple electronics element, and won't kill things that you don't want or expect to.A large piece of single sided PCB etched into a form of well spaced tacks, alternate ones to ground and a HV supply works, too, put in a cage to keep out cats and other pets, but if only one rat enters, it gets zapped, and being fairly intelligent the others, err, smell a rat (sorry....) and keep clear. It also zaps birds and other "nice" critters, so is not very selective. For lots of rats the cage traps, rat bait, fenn traps or a good small terrier are alternatives.I am unsure if an electric fence energiser has enough clout to kill a rat, probably not instantly. Possibly worthy of investigation.I have a 6kV 1.5 amp DC supply and a vacuum relay, but I think that's a bit OTT.....

author: Greorge
author_rank: Regular Contributor
timestamp: June 19, 2015, 10:31:30 pm
content: Chris,Could you make picture of that wire cage with few other details in it?One thing for sure mice and rats are very smart and spring traps after one or two catches, get raided without being triggered.

author: Greorge
author_rank: Regular Contributor
timestamp: July 03, 2015, 02:18:15 am
content: No pictures?

author: Greorge
author_rank: Regular Contributor
timestamp: June 26, 2019, 11:49:40 am
content: Out of interest made search today for "Electronic … trap" and got this page.

author: digsys
author_rank: Unknown
timestamp: June 26, 2019, 12:39:56 pm
content: I describe how I did it many years ago in this recent thread -https://www.eevblog.com/forum/projects/how-to-electronicly-detect-a-pest-trap-has-been-triggered/msg2501346/#msg2501346Very simple and designed for HEAPS of rats

author: Greorge
author_rank: Regular Contributor
timestamp: June 26, 2019, 11:37:55 pm
content: How nice to see your post.Could you make some kind of sketch with components and how it is wired?

author: floobydust
author_rank: Super Contributor
timestamp: June 27, 2019, 02:10:50 am
content: Ordinary HV DC from a multiplier does not do it, the start up time (squeal) spooks the rodent to run away. HV AC doesn't mess up EMG and is not as effective.You need at least 7kV in pulsing DC. The approach is pulsing a flyback transformer at 235Hz, for around 20 seconds. It would basic to build using a small MCU like ATTiny85, and control a motor for the dump. Below is flowchart for mouse trap.There are many (censored) youtube videos on different traps. They do conceal PSU details.

author: digsys
author_rank: Unknown
timestamp: June 27, 2019, 02:23:17 am
content: Describing methods is not a problem, all available on www, but posting actual diagrams, especially for a novice, is irresponsible and can be a legal minefield.You should look for a friend or club that can teach you, and point out the dangers.

author: ledtester
author_rank: Super Contributor
timestamp: June 27, 2019, 04:29:33 am
content: Perhaps all you need is a 12V car battery:Then again, maybe just a bucket of water will work... if you can just get one mouse to drop into it!(e.g. at the 6:30 mark).

author: Greorge
author_rank: Regular Contributor
timestamp: June 27, 2019, 05:10:26 am
content: Sorry for trouble to all concerned.But if there is diagram and parts list somewhere on the net I am still interested.

author: Greorge
author_rank: Regular Contributor
timestamp: June 27, 2019, 05:13:52 am
content: As to those videos on the net, comments were that they are pet rats and mice.

author: digsys
author_rank: Unknown
timestamp: June 27, 2019, 05:33:50 am
content: Quote from: GreorgeNo need to be sorry mate. The fact that you posted this, shows that you appreciate the safety concerns. It's what forums are best at.You can appreciate that the amount of energy required to kill, or seriously stun a rat (and these can get quite huge), is well enough to fry or even kill a human !!!It is likely you will find drawings or similar on www somewhere, BUT I'd always check with someone more knowledgeable before attempting them.After all, you don't want the rats standing over your limp body, laughing ... That would suck ! :-)

author: floobydust
author_rank: Super Contributor
timestamp: June 27, 2019, 05:54:36 am
content: It might be better to simply purchase a commercial unit unless you have high-voltage electronics experience and can ensure the neighbor's cat or dog or a kid is safe around the trap you build.Every youtuber hides their actual power supply to prevent copycats.The 12V (powered) ones are fake, you can see a boost-converter stashed away around the corner in the videos. Another give away is the 400V can electrolytic capacitors, some seem to have a PSU stuffed inside.You have to ask how a rat can start smoking on only 12V?sch is a simple mains-powered unit but no idea of the output voltage. It has auto on/off.