Fantastic. That gives me a good starting point. Cheers guys. I'll try and keep you filled in on how I go. Are parts expensive to make up circuits myself?

 

Are parts expensive to make up circuits myself?

Not sure I understand your question.
The parts should be cheap.
You can wire them on a small Vector board type breadboard.
Have you soldered before?

 

Not sure I understand your question.
The parts should be cheap.
You can wire them on a small Vector board type breadboard.
Have you soldered before?

Not to the quality you would expect
I know some guys here that could probably give me a hand.

 

Here is a link to the vero proto type Strip board.
Half way down the page.
Prototyping Boards
Max.

 

Just realized that C2 must be a non-polarized ceramic or film capacitor, even though I showed a polarized (electrolytic) cap on the schematic.

 

Seems like the next hurdle will be an "efficient" elector-mechanical device to implement the random movement. The electronics, ICs or microcontroller are the least power consuming part of this. How long do you expect the traps to be in place, unattended?

Ken

 

Seems like the next hurdle will be an "efficient" elector-mechanical device to implement the random movement. The electronics, ICs or microcontroller are the least power consuming part of this. How long do you expect the traps to be in place, unattended?

Ken

The traps remain in place constantly and trappers clear kill regularly, 3 week cycle for summer 6 WK winter. But the batteries need last a long time as every time they're opened for a battery change the become susceptible to damp.
The mechanical part will be a pendulum between a magnet and a coil. With positioning I should be able to get it to move back in forth for minimum power usage. Think it'd work?

 

I can't quit see how your original timing ("So say 1sec on,3off,4on,1off,6on,6off 10on.") will be efficiently implemented with the periodicity of a pendulum. Is the feather to be attached on the opposite end of the pendulum from the weight? Or, have you not quite visualized this mechanism yet? How about photos of the traps? And maybe a sketch of the way you see the feather feature added. Is it possible the add solar chargers to the traps to maintain the batteries over a longer period?

Ken

 

1. Look at MCUs (Arduino etc) as suggested before - these potentially will do all the things you want with easy tweaking of timings/input/outputs etc. All these devices can "sleep" to save power. An Arduino blinks out of the box and could solve a lot of similar applications in the future. Crutschow's solution is neat, but you might find that tricky to do if you had to find out from scratch.
2. Looks like the external circuitry could eat a lot of power - you might need a car battery for long term use.
3. How far are you from base? A wireless link could split the control stuff from the trap.
4. How about a presence detector (PIR or IR) to detect prey then activate then do the twitching.
5. Not sure what you mean by electromagnet/penulum. A servo/small DC motor/"vibration" motor would work
6. Fully support the objective. Native species don't stand a chance against introduced (deliberate or accidental) predators and need all the help they can get - e.g. in UK there is the fur trade mink wiping out the native voles and the grey "tree rat" squirrel has swamped the native reds - used to get 6-pence a tail for greys from the coppers.

 

Hi,
I am from the UK and have been developing a miniature random timer unit that simulates a flickering bulb. Before you dismiss this post read on!
I know you don't want a flickering candle effect but I could easily change the program to give longer random time periods of the types you mentioned.
The unit consists of a very small microprocessor with an output stage capable of driving 12V DC and up to 240mA. The output current could of course be increased by adding a small relay then you could drive almost any voltage you wish. The unit would work down to ~6V on small batteries, (9V would be better), and consumes very little power.
Have a look at the size of the unit on the shown in the video on my Facebook page and if you are interested contact me via the page and we will see what we can do for you and your birds. I have never seen a Kiwi before so I am interested ;-)

https://www.facebook.com/NTElectronics-UK-331898757164343/?ref=bookmarks

 

Do you have sun down there on the underside of the planet? Can you put a cheap solar battery charger unit to back up the batteries?
On a side note, you must have some stupid cats there! My cat would watch your contraption but he is far too smart to go try to touch it! Possibly a totally mechanical scheme would be more effective, like the automatic rat traps, but bigger.
Or a hole in the ground with sharp spikes down below and some fried chicken supported overhead. (grin)

 

I once made a passive mouse trap consisting of a bucket with some water in the bottom and on top a plate balanced on two pins. The plate was biased to one side so that it sat on a third point. The mouse would go out on the plate approaching peanut butter. When he got far enough out the plate would tip and dump him into the water. The plate would then swing back into its normal resting position awaiting the next mouse.

I was thinking of a hole in the ground too, like Ronsoy suggested. The reason for water in the bucket was to prevent the mice from being able to jump back out. Enough water in the bucket and the mouse would drown.

You're after bigger prey. Cats are not likely to go into a pail very easily, so I was thinking of a stun gun charged by solar power. A capacitor like what's found in a portable defibrillator. When the animal of sufficient size passed between the probes - BANG! A flash of lightning and off to lala land they go. Since most hunters are active during dawn and dusk you might find some problems with the stun gun. However, if Kiwi are active mid day then animals would predate on them when they're active. And the sun would be high and powerful.

I think luring a cat into a trap using a random flick of a feather - well, I have cats. Pets. And they love feathers. But if the feather flicks momentarily they don't pounce. It's when the feather is highly active that they get excited and spring.

I'm also thinking of a long string tied between two pulleys. On the string is a small rag or - if you will - feather. The feather is driven by a pulley and loops through a cage and out the other side, then through a PVC pipe back to the starting point where the feather would emerge again and entice a predator to chase and capture. Of course, running a motor and string would require far more energy than the random occasional "Unnatural Regularity" (or did you mean Natural Irregularity?).

Cats are also naturally drawn to rustling noises. So perhaps a small speaker might draw in a foolish feline or two. But keep in mind that the twitching feather or the sound of rustling will draw an animal in, but what guarantee do you have they will go in the entrance of the trap?