Hi everyone

I've just joined this forum in my quest to make life a lot easier for my chickens and me!

I have some chickens which I lock up safely in their coop at night. I put them in there and close a hinged trapdoor. However, so that they are nice and happy, I need to get up at dawn every day in order to let them out. I've been thinking about the possibility of a light activated switch system which would briefly power an electro-mechanical switch/servo. So..... the sun rises, a light sensitive device detects the light and powers something which will move a small arm (ie an arm which keeps their trapdoor closed), the trapdoor drops by gravity and the chickens run out into their chicken run. Maybe battery powered, say from a car battery??

Could anyone suggest how I can accomplish the above? (if at all). I can solder, make things and am generally handy with electrical things but I don't really know what's available or what to use. Can anyone help??

 

To me the hard part is the electromechanics. The electronics is easy. How much money are you willing to spend, and how handy designing things from scratch with motors?

I'd design the mechanical part first, like I said, that is the hard part. One idea that occurs is a motor with reel mechanism and pulleys, where gravity does the motion one way and the motor the other. Another way, which would be more secure, is a commercial gate opener.

When I was a teen (oh so long ago) I raised chickens for egg money, and had similar problems. The real reason for the door is varmints, you don't want something a skunk or raccoon can force open. Snakes can get in anyhow and anyway they want to, so I used ceramic eggs for them.

 

Be kinda awful to have the automatic door drop with a skunk or coon in the run.

 

It's not generally an issue, both those critters are nocturnal, which means they like midnight visits.

 

Does the coop door need to close at dusk as well? Or is sunrise the only input condition of concern?

Instead of a car battery, have you considered a solar cell?

 

Hi. I only want the door to open at dawn. I put the chickens away 'manually' at dusk, you see. All I really need is a light-activated something which will turn the little toggle that keeps the trapdoor closed.

Yes, a solar cell, panel or anything at all!

Do you have any suggestions?

By the way. Im in England, so snakes and raccoons are not a problem. We have two main predators... fox and badger. Both are nocturnal though, so it's highly unlikely that they will be sitting about, waiting for the trapdoor to open at dawn

 

That should be easy enough, I'd still use a very small motor, with gearing. Will the trapdoor open itself after the latch is toggled?

You'd still want battery, possibly a timer, in case the sun was behind clouds. The easy answer is a photocell except for that. Thinking about it, a photocell would still work, it would need some simple circuits to eliminate lightening from tripping it, I've seen similar circuits before.

 

To me the hard part is the electromechanics. The electronics is easy. How much money are you willing to spend, and how handy designing things from scratch with motors?

I'd design the mechanical part first, like I said, that is the hard part. One idea that occurs is a motor with reel mechanism and pulleys, where gravity does the motion one way and the motor the other. Another way, which would be more secure, is a commercial gate opener.

When I was a teen (oh so long ago) I raised chickens for egg money, and had similar problems. The real reason for the door is varmints, you don't want something a skunk or raccoon can force open. Snakes can get in anyhow and anyway they want to, so I used ceramic eggs for them.

I'm pretty handy with things but I have no electronics knowledge. The trapdoor is held closed by a small metal toggle which rotates on a screw. If the toggle end is pushed, it rotates on the screw and allows the trapdoor to fall open. So, if I could have a light-sensitive switch which would activate, say, a model aeroplane servo, that would do the trick. I could put a small pressure switch under the trapdoor so, when it opens and hits the ground, the power is cut to the servo......

Any ideas..


"All untried things are impossible"

 

That should be easy enough, I'd still use a very small motor, with gearing. Will the trapdoor open itself after the latch is toggled?

You'd still want battery, possibly a timer, in case the sun was behind clouds. The easy answer is a photocell except for that.

Yep! After the toggle is turned, the door flops open (hinge is at the bottom of the door......

 

A servo would be overkill, although it is basically the right idea. The drive for it is more complex than is needed, but the mechanics of one would work just fine. Whatever you come up with has to be water proof, or at least water resistant.

If the latch is pretty to move then a doorbell solernoid would work or some variation of it. Something that would pull the latch into a 90 degree position.

I believe the electronics would be quite simple after the mechanics is established. I'll think about it, but someone else could have better ideas.

 

Would a passive integrator work to overcome the lightning?

English translation for our poultry farmer: I'm asking my fellow geeks if a capacitor in parallel with the sensor and a resistor in series with the sensor will prevent lightning flashes from opening the coop in the night.

Perhaps something like this:

 

That's how I remember it. Short flashes of several second or less should be disreguarded, but even weak sunlight should trigger it.

Remember the electric eye circuit? CDS I think their called. Simplicity itself.

 

CdS = Cadmium sulphide. I misspelled it in my schematic above. They're still available. Don't know who might carry them in the UK, but I'm sure someone does. Other photoresistive and/or photoconductive cells are available as well.

 

maplin has a phototransistor for 0.79 pounds
http://www.maplin.co.uk/module.aspx?ModuleNo=17936&doy=15m4

they also have ldr's, but they're more expensive
http://www.maplin.co.uk/Module.aspx?TabID=1&DOY=15m4&ModuleNo=35964&criteria=

 

If you have 12v from a car battery an electric door opener from a car parts (or wreckers) place would probably work for the electromechanicals

They are cheap and have several kilos of pull.

 

Jimmy is the ultimate judge, but that does sound promising.

 

i think this can be done easily with a clock. not a light sensor using LDR. and the gate can easily be done by a switch that when the gate reaches the top most it cuts the circuit making it stop. or you can use the most sensitive LDR to have it as light sensor but the problem arise in calibrating the LDR on how much light will the LDR react to open the gates of the chicken. because when somebody at night plays with a flashlight it will trigger the LDR to open at night then your chicken will run like hell at night. calibrating it will be one of the difficult part

 

we have a simple circuit regarding LDR in one of my subject in class we play with it. it counts 1 to 9 depending on the intensity of the light. a far light intensity it is zero as you come closer it counts 1-8 depending on light intensity if your light source is so close then is counts 9. maybe you can use 9 as a switch to let your chicken out.

 

Chickens don't use clocks, they use sunlight, so it makes more sense to go with the flow on this one. The circuits are really simple to build once you get past the electromechanics, which would be the same in either case. It would also be easy to overdesign on this one, I would be suprised if it took more than one transistor and maybe a chip to interface the front end and the mechanics.

 

Yes, chickens do not use clocks, but a cheap alarm windup clock, those with the bells on top does turn the alarm winding crank when the time reaches the setting.

And that winding crank really pulls.
A string around that shaft can easily pull to unlatch whatever door with spare force.

You may want to correct the alarm time every month or so to nearly coincide with sunrise.

No solar cells, no batteries, no charger, no timers, and any chicken that oversleeps will get awakened by the bells .