Author Topic: How to electronicly detect a pest trap has been triggered.  (Read 7671 times)

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Offline Croadie

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #25 on: June 20, 2019, 03:59:14 am »
Mr Packethead

how did you get on with this - I'm really interested inthe same thing - inthe middle of setting up a predator free program in Hawke's Bay
Many thanks

Richard
 

Offline Circlotron

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #26 on: June 20, 2019, 04:48:43 am »
A magnet on the moving part and a reed switch or Hall Effect sensor on the stationary bar?
 

Offline tautech

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #27 on: June 20, 2019, 05:22:49 am »
The pic shows the kill trap in the tripped position when the kill bar is on the trigger pad.



When the kill bar is cocked and loaded it’s vertical and perfect to have a micro switch mounted on the rear frame for the kill bar to contact against.
Then all you need is the comms device.  :)
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Some stuff seen @ Siglent HQ cannot be shared.
 

Online Marco

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #28 on: June 20, 2019, 08:34:55 pm »
There seems to be some room beneath the "treadle" which will move down when the trap springs. You should be able to measure the increased proximity of the treadle. Inductive, capacitive or even optic could work ... but optical would be more sensitive to fouling. Distance too short for ultrasonic.

For the rest it depends on how available networks are. If there is good mobile phone coverage a phone modem is always an option. Otherwise LoraWAN or setting up your own 433 MHz narrowband network.
 

Offline Circlotron

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #29 on: June 20, 2019, 09:49:40 pm »
Think like it’s 1890.
Tie a string around the top of the bar. The other end of the string connects to a U shaped link that gets pulled out of a socket when the trap goes off.
 

Offline johnkenyon

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #30 on: June 21, 2019, 09:57:10 am »
The KISS principle applies here - the thing has a moving part which moves at least an inch from its armed position.

Connect two wires to the trap, and create a "normally closed" switch.

One wire connects to the trap itself.

The other wire is mechanically attached to the frame at the top, and is hooked over the arm which falls when the trap is triggered, with no slack.

When the trap is set, the wire is hooked onto the arm, circuit made.
When the trap is triggered the arm loses the wire - circuit opens, trigger detected.

When the "switch" fails, or someone nicks the trap, or the trap gets lost, all you have lost is the cost of the switch - less than 2 cents/pence/whatever's worth of wire.


 

Offline soldar

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #31 on: June 21, 2019, 04:06:21 pm »
That trap looks mean. I'd keep my fingers well clear of it.

The same as stepping on the trap releases a spring which actuates the kill bar, it should not be difficult to set a (mechanical) trigger that raises or lowers a flag or sign when the trap is triggered. No need for electricity. That would be fun.

OTOH, Shawn Woods has a YouTube channel where he has tested hundreds of different traps, some of them with remote radio notification.
All my posts are made with 100% recycled electrons and bare traces of grey matter.
 

Online Marco

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #32 on: June 21, 2019, 04:33:55 pm »
The KISS principle applies here
Just don't mix up the S's.

Adding an extra step for resetting the trap, which might mechanically interfere with its operation and which relies on predictably unreliable electrical contact ... I don't think whomever has to reset the trap would consider it simple. Whereas something under the treadle would be completely invisible, irrelevant during normal maintenance and could be made highly reliable with non contact sensing.
 

Offline icharters

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #33 on: June 22, 2019, 12:42:50 am »
Use a commercial surface mount security alarm contacts.  They come with plastic shims to keep the magnet and reed switch away from the metal.  They also screw into the trap so it violently closing isn't going to dislodge them.  You can get them in NC, NO, NO+NC types.

Honeywell 7939WG -> https://www.security.honeywell.com/product-repository/7939wg
« Last Edit: June 22, 2019, 12:47:31 am by icharters »
 

Offline Dubbie

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #34 on: June 22, 2019, 01:09:25 am »
I think you are 100% on the right track with the vibration sensor.
Means your unit can be completely sealed and just velcroed to the top of the tunnel or something. No wires or other complicated mounting.

I'm interested to hear what you are planning for the Radio also. I looked at something for an almost identical use case. However I couldn't figure out a radio scheme that would handle the distances required, considering it would be on the floor of dense bush. 
 

Offline digsys

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #35 on: June 22, 2019, 01:47:27 am »
100 yrs ago (feels like), I lived in a hippie household in Glebe Sydney, right by the water. We had a huuge problem with rats and all sorts of vermin.
All the "floaties" (dead animals etc) that choked the waterways attracted them. Rats the size of cats, the size of dogs. They'd eat through heavy storerooms doors
at night, and small 22 rifles would just annoy them. So, we made up a HV HE trapdoor. It was mounted high up and when the rat walked to the center, they were
hit with a vh energy pulse. We used various grids / cloth covered plates. The trap door opened and it'd fall into a 44 gal drum of water, making sure it drowned
if not dead. For the first few weeks, we filled the drum each night !! A "one off" approach was pointless. They bred faster than we'd be able to kill them.
Soon after, Sydney had a massive clean-up of the waterways and life went back to normal.
Maybe a similar system would be better. Doesn't need to be HV electric, but something that doesn't require resetting, and "dumps" the body.
Hello <tap> <tap> .. is this thing on?
 

Offline Zero999

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #36 on: June 22, 2019, 05:11:38 pm »
100 yrs ago (feels like), I lived in a hippie household in Glebe Sydney, right by the water. We had a huuge problem with rats and all sorts of vermin.
All the "floaties" (dead animals etc) that choked the waterways attracted them. Rats the size of cats, the size of dogs. They'd eat through heavy storerooms doors
at night, and small 22 rifles would just annoy them. So, we made up a HV HE trapdoor. It was mounted high up and when the rat walked to the center, they were
hit with a vh energy pulse. We used various grids / cloth covered plates. The trap door opened and it'd fall into a 44 gal drum of water, making sure it drowned
if not dead. For the first few weeks, we filled the drum each night !! A "one off" approach was pointless. They bred faster than we'd be able to kill them.
Soon after, Sydney had a massive clean-up of the waterways and life went back to normal.
Maybe a similar system would be better. Doesn't need to be HV electric, but something that doesn't require resetting, and "dumps" the body.
What would be cool if you had a similar system, with a shredder, next to a sewage drain: first the vermin is trapped, tghen humanely killed, minced and flushed down the toilet!
 

Offline digsys

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #37 on: June 22, 2019, 11:56:26 pm »
ok, that's a bit severe :-) and environmentally unfriendly
What I was alluding to was - IF you have a greater # than just 1 or 2 pests, doing them 1 at a time then going back every day or 2 may be a losing battle.
A simple setup we started with was an old car battery, old style ignition coil and a trigger device. If the vermin is too big though, the coil will only stun them,
is why we needed a 2nd "process".
Hello <tap> <tap> .. is this thing on?
 

Offline Chris Wilson

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #38 on: June 26, 2019, 03:25:00 pm »
Large sheet of Veroboard with tracks paralleled, suitably spaced for no arc over and connected to ground and the HV probe of a tube / vac variable HV tester. Put corn on another board so the rat walks across the charged Verobaord to get to it. The Veroboard board is hinged on a balance spring so the dead rat drops into a container, works well, and if you have a power point indoors where the HV tester can be left safely and locked ON you can run car ignition cable to the trap.  Has dispatched dozens of the blighters...As someone said a car electronic ignition system with a simple circuit to keep firing the coil will also work, and from a car battery... The less "feeling" would just let the rat drop into the container and die without killing it, not sure if the squeaking would deter others though :(
Best regards,

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Offline floobydust

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #39 on: June 26, 2019, 04:59:41 pm »
OP I would use a magnet and reed switch. Vibration sensor may not work as the soft squishy rat will dampen the trap's closing, and its weight is on the trap too.
It rain outdoors so anything else I think will fail from dirt and water.

There's several electric mouse/rat trap videos on youtube. Once the HV is on they jump up off the electrodes and run/bounce away, unless you have a cage cover or something complicated to navigate which keeps them there long enough.
 

Offline Doctorandus_P

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #40 on: June 28, 2019, 02:28:41 pm »
This trap looks like it goes off violently.
I would probably not trust a reed switch in this setup, the're too fragile, but a HALL sensor would work, or even a simple Microswitch that is activated when the trap is in the armed position.
 

Offline fcb

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Re: How to electronicly detect a pest trap has been triggered.
« Reply #41 on: June 28, 2019, 02:58:23 pm »
I think I would use audio - that trap is going to make a sharp sound when it goes off - so use a microphone in the equivalent of a PIR sensor circuit. Could be made with very low idle current, easy to adjust and test.  The output would drive a pulse stretcher (comparator) which goes to whatever you need to drive.

https://electron.plus Power Analysers, VI Signature Testers, Voltage References, Picoammeters, Curve Tracers.
 


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