I want to build a circuit to let my chickens automatically in/out

[richlewis34]

I know not much about electronics, but am fairly handy..and had a 200-in-1 project kit as a kid!

I have seen for sale an electronic controller that activates a motor that raises a hatch at sunrise, and closes hatch at sunset

Theory is that I can let me chickens out automatically at sunrise, and after they return before dusk the circuit will shut them in

Can anyone help me build this please?
It will be a learning experience for me, and I should be able to do it for a lot less than the £125 they wanted for the manufactured version!

Reckon I need some adjustable photosensitive cells, a motor circuit, some relays...power source..can I use mains(preferred) or should I use batteries?? and some sort of timer/reverser switch for the motor..does the motor need to have a timer or should it be stopped by positional sensors?

Many many thanks...I look forward to meeting some of you guys over the web for an interesting project!

Richard

 

[crutschow]

Haven't been around chickens much since I was a kid on the farm. As I recall they weren't the brightest bulbs in the barnyard.

Attached is a schematic for my concept on how to control the door. The photo cell controls a relay that is shown in the up position during the day and the down position during the night. The door (or motor) has two limit switches, one for up and one for down. As can be seen, when the Photo Cell relay changes states, the motor will be energized to move the door until the appropriate limit switch opens and stops the motor.

The motor can be powered by the mains or whatever power source is appropriate. Reasons to use a battery are, if you want it to work if the main power fails, or for safety. If you power from the mains, your must be careful to insulate all connections to the limits switches, etc. so no lethal voltages are exposed.

Also, you would want to have some way to easily open or close the door manually if needed (perhaps a quick release connection for the actuator rod).

The photocell could be the kind they sell in many hardware stores to control outside lights.

For the door actuation you could use a motor with a gearbox reduction which drives a wheel or crank with a diameter equal to the distance you want the door to move and with a connecting rod to the door. Thus the wheel/crank moves 1/2 revolution to open or close the door and always moves in one direction.

The limit switches can microswitches positioned to sense the door or motor crank position.

I don't see any need for a timer. For safety you may want some sort of IR beam sensor which would detect anything in the door opening and stop the motor. Perhaps something similar to the sensors they sell to detect when someone goes through a door at a business.

You probably also should have some method of protecting the motor if the door jams. Perhaps some type of slip clutch or motor overload protector.

So building all this should be a good test for your handiness. Have fun.

P.S. Let us know how the chickens like it after it's built.

 

[Boncuk]

automatic chicken hatch

Hi richlewis34,

there are purely mechanial devices on the market. They are normally used to let cats walk out and in.

They havea four position slider: Out only, in only, both ways and locked

It is manufactured of plastic and the door itself is made of acrylic glass. I don't know if chicken are smart enough to learn how to lift the "door".

Another way would be a bunch of losely vertically mounted small metal bars (bycicle spokes), each moving individually. The chicken will only be forced to move those bars where it passes (this is also used for pigeons). The locking can be made with pushbars operated by latching solenoids from the buttom for each desired direction.

With a device like that you take care of the slowest chicken to return home. With a fully locked door the late chicken might fall victim to a fox.

Look at the illustration for rough details.

Regards

Hans

 

[mneary]

I would use an RC servo ($10-$20) for the ready made mechanical subsystem and built-in limits. A 555, PIC, or AVR can be used to generate the pulses needed to set two or more positions of the door.

 

[crutschow]

Junkyard Motor

Richard:

Some thoughts on a low cost motor hatch actuator:

A motor with a gearhead that could be found at an automobile junkyard and has good torque is an automobile windscreen wiper motor. Although they usually only run in one direction, I believe they will reverse if you reverse the input power polarity. They are similar to the one at **broken link removed**

It probably doesn't have enough torque to operate a crank as I previously proposed, but it could operate a small pulley attached to a stranded wire cable. The pulley could wrap up the wire to pull the hatch open. Reversing the motor would unwind the wire, and gravity would close the hatch. Alternately you could run the other end of the cable to the bottom of the hatch with an idler pulley so it would pull the door closed as well as open.

This motor can be run off a 12V battery or 12V power supply. If you use a small 12V rechargeable battery with a trickle charger, the system will continue to operate even with a mains failure (if the photo cell can operate on 12V). You could keep if totally free of the mains if you used a solar cell to charge the battery.

Since the motor needs to be reversed, the connections are slightly different from my previous post. Attached is a schematic. It now requires a DPDT relay for the photo sensor rather than the SPDT previously shown.

 

[slopagafud]

A motor with a gearhead that could be found at an automobile junkyard and has good torque is an automobile windscreen wiper motor. Although they usually only run in one direction, I believe they will reverse if you reverse the input power polarity.

You could use a power window motor. They have plenty of torque and are reversible. not to mention the fact, they tend to be much smaller than wiper motors.Window motors are much easier to wire (2 wire) as opposed to wiper motors which tend to have 4 or more to control various speeds(depending on application)
The RC servo is a good idea but mat be more complex than what Richard is looking to build. Depending on the size and weight of the door though, he may need a high torque servo which wont break the bank, but, can be a little costly($60-$100 US)

 

[crutschow]

You could use a power window motor. They have plenty of torque and are reversible. not to mention the fact, they tend to be much smaller than wiper motors.

Also you may be able to get the window motor with the actuating mechanism that could directly move the hatch.

 

[slopagafud]

Also you may be able to get the window motor with the actuating mechanism that could directly move the hatch.

A definite possibility, as long as space is not an issue. The regulator side of the mechanism tends to be rather large and must be secured in several places unless modified. But, if he has the space, he could set up a really cool system by surface mounting the assembly (slightly modified) on the front of the house and slide the door open and closed rather than swinging it.