I want to make a motion activated rat trap using a 12v pir, a 230v adapter putting out 12v at 1amp and a linear solenoid. What else do I need to make it work?
Thankd

 

Some bait?

 

I invented one about 25 years ago, but it never sold. It was not a shock type, so moderators can relax. It was intended for grain warehouses where the rats ran havok.
It used a two-pint sized air tank, a solenoid air valve, a light and a beam-break switch to trigger the air valve so that the rat was launched backward out of the tube at about 120 feet per second, and would suffer a fatal collision with a steel plate over a barrel that would be emptied of dead rats daily.
It does require a supply of compressed air at 120 PSI, but hardly any flow. One small air compressor can power many of these in a large warehouse. The power consumed was mostly for a small light in the bait compartment near the air valve.

The whole purpose of the device was to cause a fatal collision between the rat and the steel plate. It was tested with wormy apples and it was quite effective in producing fatally damaged wormy apples.

 

I invented one about 25 years ago, but it never sold. It was not a shock type, so moderators can relax. It was intended for grain warehouses where the rats ran havok.
It used a two-pint sized air tank, a solenoid air valve, a light and a beam-break switch to trigger the air valve so that the rat was launched backward out of the tube at about 120 feet per second, and would suffer a fatal collision with a steel plate over a barrel that would be emptied of dead rats daily.
It does require a supply of compressed air at 120 PSI, but hardly any flow. One small air compressor can power many of these in a large warehouse. The power consumed was mostly for a small light in the bait compartment near the air valve.

I can imagine seeing rats flying through the air into a barrel. A bit like a production line.

 

I invented one about 25 years ago, but it never sold. It was not a shock type, so moderators can relax. It was intended for grain warehouses where the rats ran havok.
It used a two-pint sized air tank, a solenoid air valve, a light and a beam-break switch to trigger the air valve so that the rat was launched backward out of the tube at about 120 feet per second, and would suffer a fatal collision with a steel plate over a barrel that would be emptied of dead rats daily.
It does require a supply of compressed air at 120 PSI, but hardly any flow. One small air compressor can power many of these in a large warehouse. The power consumed was mostly for a small light in the bait compartment near the air valve.

In the absence of the steel plate, what would be the range? Could it be used like a mediaeval siege engine to propel dead rats into the enemy camp?

 

In the absence of the steel plate, what would be the range? Could it be used like a mediaeval siege engine to propel dead rats into the enemy camp?

In an earlier experiment a similar assembly with a 4 foot aluminum pipe barrel was able to send a juice can full of water about 100 yards (300 feet), using 110 PSI air pressure. Water was used because it was cheap and safer than the intended load. THAT DEVICE WAS RATHER DANGEROUS!!! It used a one-inch solenoid air valve.

The Rat-Trap system (aka "Ratapault") used a half inch pipe sized solenoid air valve, selected because of a lower cost. It was never actually used in a warehouse because those involved thought the idea was "Crazy." But it was the only self-clearing, non-toxic, non fire hazard rat weapon aside from trained animals.

So here is an offer to anyone who wants to address the rat problem commercially anywhere in the world: I would supply a detailed enough description for anybody to produce these devices to address the rat problem that is certainly contributing to hunger. No royalty fees required. Just acknowledge me as the inventor.

 

In an earlier experiment a similar assembly with a 4 foot aluminum pipe barrel was able to send a juice can full of water about 100 yards (300 feet), using 110 PSI air pressure. Water was used because it was cheap and safer than the intended load. THAT DEVICE WAS RATHER DANGEROUS!!! It used a one-inch solenoid air valve.

The Rat-Trap system (aka "Ratapault") used a half inch pipe sized solenoid air valve, selected because of a lower cost. It was never actually used in a warehouse because those involved thought the idea was "Crazy." But it was the only self-clearing, non-toxic, non fire hazard rat weapon aside from trained animals.

So here is an offer to anyone who wants to address the rat problem commercially anywhere in the world: I would supply a detailed enough description for anybody to produce these devices to address the rat problem that is certainly contributing to hunger. No royalty fees required. Just acknowledge me as the inventor.

I would love to have a chat. Can you email me?

 

I can try to send a P.M. via this site. Not sure it will work, but I can give it a try.

 

This thing is impressive! I always wanted to design an all-electric version.
Capacitive sensing- a great low-power sensing mode, especially inside a tube.
A gear motor to wind up a monster spring.

 

This thing is impressive! I always wanted to design an all-electric version.
Capacitive sensing- a great low-power sensing mode, especially inside a tube.
A gear motor to wind up a monster spring.

This is what led me to this site! Trying to make something like this.

 

The stupid thing about the yoo-toob video is that it did not give a single word of explanation about what the product that it was advertising was doing. Not one tiny word. Was it poison gas? or a fatal injection? or what???
And certainly the sole purpose of that video was to advertise the product. Was it an accurate portrayal? Or just another faked presentation like so much stuff shown there???
With current video editing software the entire thing could certainly be faked. We all know that.

With the "Ratapalt" , the description of the mechanization is totally clear, and every bit of detail is freely available to any who wish to produce copies. Food loss thru rodents is a problem around the world and so my invention is an effort to assist in reducing world hunger.

 

If you are still considering a PIR sensor you might want to obtain some sensors and some rats to see what it would take to reliably sense the in different environments (seasons). If rats were red hot it would be a cinch, but they might not trip the detector as easily as we can imagine.

They are not terribly hot or colds and are small radiation sources. It may take a long time to get all of the parameters right.

 

For my design a beam-break sensor will be the best choice, because the trip point will not vary enough to matter.
PIR sensor sensitivity and range vary inversely with temperature because they sense contrast. At ninety degrees in the summer my light sensor will not always trigger, but when it is well below freezing outside it will trigger on a squirrel at 80 feet.

 

The stupid thing about the yoo-toob video is that it did not give a single word of explanation about what the product that it was advertising was doing. Not one tiny word. Was it poison gas? or a fatal injection? or what???
And certainly the sole purpose of that video was to advertise the product. Was it an accurate portrayal? Or just another faked presentation like so much stuff shown there???
With current video editing software the entire thing could certainly be faked. We all know that.

With the "Ratapalt" , the description of the mechanization is totally clear, and every bit of detail is freely available to any who wish to produce copies. Food loss thru rodents is a problem around the world and so my invention is an effort to assist in reducing world hunger.

You need to cross-reference to got the full picture.

The device uses a piston powered by CO2 gas to crush the rodents inside the tube.
The unit auto-resets, and the dead rodent drops out due to gravity, it's then ready for the next one.

A very clever and reasonably humane device.

 

OK, so crushing is humane??? In the ratapalt system the rat exits at about 100 feet per second and impacts a solid steel plate, or a sharp blade, or continues out into the bay and hits the water far fro shore. And then is ready to do it again, every minute of every day, as long as the building compressed air system is active. One air compressor can power quite a few ratapalts, because they only consume air to reset. No expensive compressed gas cartridge needed. The only service required is to remove the pile of dead rats, which would not be close to the entrance to the device.

 

I’m thinking a PIR would have too broad of a field, opposed to beam. Rats in my neighbourhood vary considerably in size depending on age, having me lean away from an air canon. The outcome of anything that couldn’t fill the bore, could be disturbing. I just keep reloading the Victor. But I’m probably off course and your using a piston.

 

I’m thinking a PIR would have too broad of a field, opposed to beam. Rats in my neighbourhood vary considerably in size depending on age, having me lean away from an air canon. The outcome of anything that couldn’t fill the bore, could be disturbing. I just keep reloading the Victor. But I’m probably off course and your using a piston.

I covered the sensor scheme in post #13. As for the various sizes, the mass air flow will carry smaller items along quite well. And deformable items get reshaped to fill the tube almost instantly, with an air bearing surround that reduces friction. That is an interesting instance of the "Coanda Effect" that not everybody is familiar with.