Cockroaches or Blackbeetles are nasty pests living in our house, carrying germs to our food and drink. People have tried all kinds of ways to get rid of these annoying neighbors, poison, trap, even laser. In Hollywood, bugs (mostly cockroach) are always the negative symbols in Sci-Fi (Man in Black) or Dracula (They nest) movie. However, Cockroaches have a huge family. There are about 4000 species of cockroach, of which 30 species are associated with human habitations. People can not kill cockroaches completely, since they have strong eggs protection. Killing one cockroach sometimes brings more baby cockroaches.
To be frank, I am sick when I typing the word cockroaches. Because I remember a horrible scene when I knocked a sewing machine in my last moving house. Hereafter let us call its abbreviation CR.
I saw a TV show of CCTV-10 in China last week. This show introduced many innovative killers for all kinds of annoying creatures, from mosquitoes, flies, mice, to CRs. No wonder why people created so many tools to kill them. They brought so much pains and illness to us. Do you remember the Black Death, which kills half population in Europe. OK, enough! Let me introduce the champion of the CR killer.
This CR killer has been patented in China and other countries. The inventor Mr. Zhang designed this killer because one CR dug into his ear!
You can order one CR killer (Branded Li Qun) from China. It is not cheap as most people expected. Each one cost RMB380, about 38 euro, including two boxes of CR attractant, excluding shipment and tax. Alternatively you may build it, but selling it maybe a legal issue. You'd better to negotiate with the patent owner to license it for mass production.
This device is an electronics killer, which is made up of infra red detector, high voltage discharger, and heater. At last, the cooked CRs will be processed into a CR attractant in this killer machine.
CRs are highly social creatures with high reproduction rate. The best way to kill them is killing them as well as their eggs. Each CR egg contains more than 5000 eggs. The egg pod is so strong, that people can hardly destroy it. People find a way to destroy the egg pod and kill the eggs, by spilling boiling water at the CR bodies and egg pods. However, more people usually smash and throw them out. That may leave more eggs in the world, or your house.
- First, the captured CRs have been processed as attractant. Don't worry, it is clean, there is no CR body at all. You can put some attractant in the feeding slot.
- Once the CRs smell the attractant, they will think their buddies are sharing some food together. As a result, they will enter the killer.
- Once any CR enters the welcome slot, the infra red sensor will be invoked and triggers the following high voltage discharger.
- The high voltage discharger layout looks like a pair of forks. The working voltage is about 3000V. The inventor directly uses a baton FBT flyback transformer for killing a bug! The power can shock a person.
- Once the CR steps on the discharger, of course it will be shocked and falls into the heater.
- The heater heats up, and the CR is cooked as well as the egg pod.
How about the performance for the killers? Dude, you must check out the video chip listed in the reference web address. I am sorry there is no English video or caption. You can skip the video to 12m00s to have an overview for its performance. In one night, 76 CRs were killed in a demonstration spot.
I have not prepared detail schematics of CR Killer for your guys, because I think the circuit design is quite simple. I just introduce some key components and reference designs for you.
Infra Red Sensors: The infra red proximity sensor is easy to build, easy to calibrate and still. It provides a detection range up to 35cm, depending on the ambient light intensity. The solution contains only a couple IR LEDs, an Op amp (LM358), a transistor and a couple of resistors. Please refer to the web page listed in the references.
High Voltage Discharger: You can use diode based double voltage circuit. However, the working voltage is not high enough to stun the CRs. I recommend the FBT flyback transformer for this application. AC flybacks are simply ferrite transformers, AC in equals AC out, but DC flybacks include a rectifying diode and often a multiplier stage inside. AC flybacks are found in older CRT televisions and the rectifier and multiplying circuits will be found separately inside the television. Once you have the transformer, a few common components are enough to complete the circuit and generate high voltages. Don't bother to make a transformer by yourself. An off-the-shelf high voltage discharger used in the spontoon is recommended.
Heater, basically a heater coil used in your hair-dryer.
Power Distribution, we need both AC and DC power in this application. The infra red sensors requires low voltage in 5V or 3.3V DC. The FBT flyback transformer requires 12~15V DC input. The heater requires AC main supply.
We may need a simple microcontroller for the killer to infra-red detection, timer control for discharger and heater. The application is so simple, even a 555 timer is enough for control the state-machine for the killer. We don't expect the killer collect the data and send email for reporting, we just want it kill as much as possible. Of course, the users have to inspect it regularly. Otherwise, we can consider adding a counter and an alarm function in case the killer can not keep so many bodies.
Electronics Cockroaches Killer Video Chip CCTV-10
I love invent, a TV show in CCTV-10, killing mice, mosquitoes, flies, mice, and CRs
Infra Red sensors applications and construction
Flyback transformer in HvWiki