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Yet another chicken coop door...

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Dodgerdoob

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Hey everyone. I'm really glad I found this site, I have electrical questions fairly regularly and now I have a resource to answer these simple questions.
My current situation is that my wife and I have bought a small farm and have got a small flock of poultry. We both have variable schedules so it makes letting out and shutting up our birds on a schedule difficult. What I need is an automatic coop door opener. I've seen commercial models that seem to work ok, but they are fairly expensive. And, I don't buy anything I think I can make. After some internet research and study, I have what I feel is a pretty good plan. Solar panel to charge controller, to SLA battery. One pair of leads to 12V digital timer, one pair of leads to a DPDT relay. The timer is wired to the control pins. Then relay to car window motor. Some where on the door track there are limit switches that stop the motor. My theory is that the timer switches "on", raises the door, trips the limit switch and the door stays up through the day. Timer shuts "off" and the door lowers until the lower limit switch trips and the door is shut and locked. So now on to the questions. What size solar panel do I need? 1 watt, 5 watt, etc. Our shortest day in Central Indiana (winter solstice) still produces 10 hours of light, if that factors in. Do I need a controller for a small panel? I do a lot of ebay shopping, will one of the generic ones from Hong Kong for $5 work? Same for the relay and and timer. I figure since all the electronics are ultimately made there anyway, why not cut out the middle man and the markup? Will leaving the timer on draw much current and deplete my battery? I would guess not since I'm only powering the relay. And on that note, what size battery do I need? The actual full 12V draw (motor actuating) is probably only 5 seconds in a 24 hour period. 5 to 7 AH SLA batteries are cheap and plentiful, would one of those work? Those are the only things I can think of right now except for one side idea: some of the charge controllers have a PV cell for controlling outdoor lights. These have preset settings so you can vary the length that a light is on. Chickens require 14 hours of light to activate their egg laying cycle. If I used one of these charge controllers, could I connect an efficient LED 12V light on the "load" terminal that would be activated by the internal PV sensor and then run my door opening system directly of the battery terminals? The battery terminals would also be connected to the "battery" terminals of the controllers. Any issues with that? This is just an afterthought, I could use an independent system for light. Thanks in advance. I'm excited for the possibilities this project could start. Thanks also to Cowboybob for your encouragement.
 
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I would think a 5 to 7AH (not mAH) 12V SLA battery would be sufficient for your needs, depending upon how much current the timer and relay require . A 5W-10W solar panel, such as one of [URL="https://www.batterystuff.com/solar-chargers/#10771"]these,[/URL] should serve to keep the battery charged.

Whether you can also run an LED or not on the same battery would depend upon the current requirements of the LEDs.
 
Then relay to car window motor. Some where on the door track there are limit switches that stop the motor.
How will you stop from dropping the door on a chicken???
What if one is left outside?
 
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I'll need to make the door frame an uncomfortable place to hang out. They're either in or out. Chickens have fast reflexes, if the door starts closing while one is walking in, it would be gone before the door could catch it. As far as one getting locked out, there are a few things that make that unlikely. They are flock animals that move as a tight group. If one is in, they're all in. They are very much creatures of habit, going in at the same time every night. Using a timer instead of a PV cell insures that the door closes at the same time every day regardless of weather. Setting it to close 30 min after sunset gives a wide window for them to go in. If one gets locked outside, it perches outside until tomorrow. If a predator comes around, I lose a bird. If I'm working late and the door isn't closed and a predator comes around, I lose all my birds. Thats math even I can understand.
crutschow, is the issue of a 12V led requirement one of wattage or amps? What figure am I using to determine battery size for the addition of a night light.
 
OK I see many chicken coop door openers on google.
The 1st thing I can tell you is to run off a battery and solor cell you should use a smaller motor.
You should have two relays one for up and one for down.
I have seen many differant controllers, from Arduino's to simple timers.
 
I've done the google search thing and seen a lot of people parading their openers, I need to know the actual way to wire one. And I've seen at least 3 that used a 12v power window motor. I too have seen arduinos, timers, photo cells, an old fashioned alarm clock, manual switches from the house and one guy trying to hook his up to the internet for some reason.
 
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crutschow, is the issue of a 12V led requirement one of wattage or amps? What figure am I using to determine battery size for the addition of a night light.
You can't have one without the other. From the battery point of view it's amps since batteries are rated in ampere-hours.
 
Will leaving the timer on draw much current and deplete my battery?
If you use a CMOS-based timer the answer is no. A non-latching single relay, on the other hand, will draw significant current for half of each day. Better to use a latching relay or 2 relays (as suggested above... one for open, one for close), powered only for a few secs when needed.
 
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Dodgerdood, Welcome!

Per your request, here is a schematic for the chicken door actuator you asked about.

<EDIT>Wrong schematic. Will replace shortly

There are readily available relays that draw very little power.

Correct Schematic attached.
 

Attachments

  • Chicken Door Controller.JPG
    Chicken Door Controller.JPG
    93 KB · Views: 2,638
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Have you thought about using a photocell switch and shut/open the door when it starts to go dark/light.
A seperate battery for your door and your lights would be a good idea.
 
I was going to go with a photo cell, but the variation in light here in the winter would cause problems I think. Who hasn't seen a security light on in the middle of the day because of a winter storm? If its a bad weather day, the onset of dusk can change by as much as an hour. A timer gives me a positive open and close time. Every few weeks I can add or subtract a few minutes as the seasons change. Also don't let my previous posts suggest that I don't check on my birds every day. This just gives some added security and is an opportunity to build a cool gadget.
 
There is an interesting type of timer called an Astronomic Timer which automatically adjusts for the change is the length of the day with the date. Here is an example that operates from an internal battery and will control DC loads. I have a similar one that controls my outside lights. Perhaps that would work for you.
 
I'd seen those and thought about one, but since this isn't a totally autonomous system( I'll still be out there every day feeding and checking on them) I don't think the cost is worth it. They run about 4 to 5 times as much as a simple controller. If it was a large outdoor lighting array or I wanted something that I was never going to interact with I think they are a great idea.
One other thing, should the inline fuse be the same rating that the motor is now, or should it be reduced because this is a "lower powered" system than what it came from?
 
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The motor start current will be ~ same as before, so the fuse should be the same.
 
If its a diode its pointing the wrong way.
 
Not a diode. It's a "current arrow", a metering device used to monitor current in the SIM's DC analysis routines.

I forgot to remove it from the schematic before taking a "snip" of the circuit.

Here's the replacement JPEG without the arrow:

View attachment 68647

Thanks for the heads-up, 4pyros.
 
OK with a small motor, two relays and two limit switchs you could run this off a SLA 7ah battery and keep it charged with the right size solor panel and an isolatoin diode.
 
I'dve thought so, if your solar panel can chuck out more than an amp then a charge controller might be a good idea.
 
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