Automated chicken feeder

Transporter in action

This is a picture taken with the motor turned on. It takes about 10 minutes to supply 250g - 300g of food. A plastic tube will be mounted over the hole to guide the food and protect the chickens from hurting themselves

The controller

What’s nice hardware without some software behind it to make it all happen? I had to find a controller that would run independent, consume almost no power, turn the system on at the desired time and turn it back off once enough food was delivered. After a few (silly) ideas I discovered a digital timer you could plug in an outlet to control stuff (like lamps or coffee machines) Inside the whole system consists of 3 parts: the power plugs, the digital part and the small circuit board that changes 240V AC to 24V DC and 3V DC and switches the relay. The 24V is used to drive the relay so we won’t be using that, the 3V is used to power up the digital part and that is what we need.

Since the current consumption of the motor is very low I can switch it using a transistor only. I used a BC547C (NPN transistor) because they can draw 100mA and my motor only needs about 30mA.

The internals of the timer are completely stripped out and only the digital part remains. 3 wires are coming out of that PCB: 2 for power and 1 control line. It took my a while to discover how the control line was working but after I while it became clear that it was connected to ground through a transistor when the system was off and disconnected from ground when the system became active.
To use that signal for controlling a transistor I only needed to add a pull-up resistor between the positive supply and the base of the transistor.

In my first design I made the 3V using an LM317 (adjustable voltage regulator) . The design looked like this:

This circuit worked fine but it had one major disadvantage, it consumed about 20-25mA. This is too much for a system that has to run on batteries. WARNING: INSIDE THIS SYSTEM ARE MANY PARTS CONNECTED THE THE MAINS. DO NOT TOUCH ANYTHING WHILE THE SYSTEM IS CONNECTED TO THE POWER. IN FACT, DO NOT OPEN IT AT ALL UNLESS YOU ARE 100% SURE OF WHAT YOU ARE DOING. I AM IN NO WAY RESPONSIBLE TO WHAT YOU DO TO YOURSELF, RELATIVES OR THE TIMER

Reducing the power consumption
The next challenge was to get the power consumption to a level where it could run on batteries or solar panels.
Making a small calculation I found that I lost about 177mW of power in the LM317. That was an efficiency of less then 26% (later I found that it was even worse than that).
Linear power regulators have the problem that they transform the complete voltage difference between input and output to heat. The obvious solution was a switching power supply.
After some struggle I managed to get a
MAX5033. It requires some, easy to get, external components and should have a much lower consumption.

This is the diagram I copied from the maxim datasheet that shows how the chip needs to be configured:


The result of this chip were magnificent, the consumption dropped to 2.5mA !!!

It’s finally working !!!

With the new controller in place the system should work for about 200 days on a 16Ah battery. I will add solar panels as well in the future but for now I’m happy the way it works. On the photo you can see the MAX5033 with the components to transform the power from 12V to 3.3V. On the top right is the transistor that switches the motor, there is also a diode in reverse over the motor connection to absorb any reflow of current. The transistor BC547C can draw 100mA and since my motor only consumes around 30mA this is more then enough. When you want to use a bigger motor you might need to use another transistor or a relay. Right now the system turns on at 8.05h in the morning and runs for 11 minutes, that way the chickens get the same amount of food as before.

This article has been reposted with permission of Tom Boschman. (c) 2005 Tom Boschman The original article was posted at chickenfeeder.blogspot.com

10 Responses to “Automated chicken feeder”

1. Aaron Says:
   November 9th, 2005 at 2:56

   I’m all for making things easy. You can use chickens as part of a permaculture system, where the chickens fertalize, weed, and till the ground all at the same time. Best of all, minimal work for you. Move their pen, and you can plant next year’s crops there.

   What could be better than letting them fend for themselves? Just check on their food every week or so, and get the eggs at your leisure.

2. jazz Says:
   January 19th, 2006 at 12:16

   Well done mate.
   I have been thinking about making one of these for a while.
   I have experimented and failed thus far.
   The loose spiral wire is brilliant.

3. PRESTON NYAUNDI Says:
   March 12th, 2006 at 5:53

   I would like to know more about the project eg. its layout please.

4. stevo Says:
   March 19th, 2006 at 22:25

   tell me, why does this need a motor? why dont you just use gravity? what a waste of time… get a job you bum

5. Tim Says:
   May 7th, 2006 at 9:43

   Cool idea. It’s a shame ’stevo’ is quick to stomp on your creativity.
   I’m sure ’stevo’ has a website article showing his ambition, effort,
   and dedication to turning his ideas into reality - yeah, right.

6. Dan Says:
   August 11th, 2006 at 1:14

   Wow this is a really great project i’m hoping to make one myself!! The only things i’m slightly stuck
   on is when you say copier motor well what exactly do you mean and did you buy or make the spiral if so
   what name did it have! many thanks!
   p.s this site is great and i find it 1st pages on google lots!

7. Maggie Rudy Says:
   August 16th, 2006 at 19:22

   This puts me in mind of a device I’d like to have for my chickens: an automatic coop door openercloser that would be triggered by light level. That awy I would be able to go away overnight knowing my hens would be shut up tight at night and let out at sunrise. Sadly I am mechanically deficient, so it remains a dream.

8. Rob Says:
   August 23rd, 2006 at 4:36

   Fantastic. I’ve made a chicken feeder where, when a chook steps onto a plate, a door opens giving the chook unlimited access to food. The closed door stops feral birds and mice from getting a free feed.
   My next project is an automatic door that lets them out at midday and closes on dusk. Any body got a design (circuit diagram for a timer and LDR input)? I guess Stevo can’t read or conceptualize a basic concept.

9. Gary Clark Says:
   December 23rd, 2006 at 16:02

   Rob, I like the sound of that chook feeder where they stand on a plate to open the door. I bought something similar recently but getting the chooks used to it has been dificult. Some still run off as soon as the door opens as it opens quite quickly and makes a noise too. Would be interested in seeing a picture of yours if possible. Maybe it’s better than the one I have. Keep up the good work,
   Gary. garyclark@slingshot.co.nz

10. Wilfredo de Macedo Says:
    September 2nd, 2007 at 12:10

    Hi Tom : I love your ideia,and using the it I´m thinking that could solve my problem to feed two aviaries gages with cocktaiels and finchs that I have, when I went out of my house on weekends and hollydays.I intend to make a smaller one of this feeders working like yours. What do you think ?
    Wilfredo

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