Chicken Coop Door Opener

Thread Starter

flumes

Joined Jun 6, 2016
1
I have a 12 volt linear actuator that I am hoping to use to open/close a door in my chicken coop at certain times in the day.

The linear actuator has built in limits and operates at less than 5 amps, but I would rather use seperate limit switches to control the amount of stroke the actuator has.

I am thinking of using a 12V power supply connected to a digital timer to send power ( + - ) in the morning to open the door. I would then use a different timer to send power (- + ) in the evening to close the door.

Any ideas how I can make this work, (using relays and micro switches)?

Any help would be appreciated.

I will by beer :)
 

crutschow

Joined Mar 14, 2008
25,702
You could use a single sprinkler type timer (such as this) since they have more than one output.
Note that the output of these timers is typically 24Vac so the relay coils also needs to be 24Vac (example).
Here's a conceptual connection diagram for the relays and limit switches.

The timer output takes the place of the switch, with the relay coil returns going to the timer output instead of the motor power supply.

Edit: Note that relay contact protection from the inductive motor kick is not shown and should be added.
For that you should connect two diodes (1A or greater such as 1N400x) to each motor connection (4 diodes total), one V+ to motor (anode) and the other V- to motor (cathode).
 
Last edited:
Find a timer. Decide on a power supply for the timer.

Two SPDT Bosch Automotive style relays hooked up the right way (see power door lock wiring) will give you an OPEN//CLOSE relay.
The wiring method causes the motors to stop fast.
The limit switches basically would interrupt the respective OPEN/CLOSE coil.
For DC, you should use reverse biased diodes on the relay coils.

Now, you can turn these two OPEN/CLOSE signals into an ON=OPEN, OFF=CLOSED from your timer.

Would chickens prefer an autonomic timer? A timer that can turn on/off based a time before after sunset/sunrise?
 

crutschow

Joined Mar 14, 2008
25,702
How do you stop the door squishing a chicken?
Two things make that unlikely:
The door probably moves slowly enough that the chicken would naturally have plenty of time to get out of the way.
The door is normally closed after sundown to make sure they are all already back in the coop. You don't want to close the door with any still outside (where they can become a tasty meal for night-time predators).
 

GopherT

Joined Nov 23, 2012
8,012
If you use external limit switches you will have to teach your chickens not to mess all over them ;).
I would just use a current sense resistor and assume it is closed one enough current is drawn in each direction. I would be using a motor and toothed belt instead of a linear actuator.
 

splud

Joined Jun 30, 2013
16
If you use external limit switches you will have to teach your chickens not to mess all over them ;).
FTR, limit switches can be placed in the sides of the door frame on the side and ABOVE the opening and trigger on detents in edges of the door. This keeps them up and away from debris. The head of an old toothbrush or part of a paintbrush can be used as a brush near where the edge of the door runs into the track, knocking away any debris carried up by the door, so that is stays away from the switch.

I've constructed a couple of auto coop door openers, and used a small geared DC motor, operating it more as a regulator, with the door (a piece of galvanized sheetmetal with the bottom edge folded over so it isn't sharp) counterweighted. In such an arrangement, there is not much apparent weight to the door. Think of old-school double-hung windows.
 

Mouthpear

Joined Dec 24, 2018
25
I would just use a current sense resistor and assume it is closed one enough current is drawn in each direction. I would be using a motor and toothed belt instead of a linear actuator.
Why would you use a belt that would actually be more prone to wear and tear and can break. Not saying that it will happen on the daily but why bother when a linear actuator is much stronger, easy to install, limits are built in and if failure occurs the door doesn't come crashing down.
 

Mouthpear

Joined Dec 24, 2018
25
Presumably a magnet and a couple of reed switches would avoid the problem?
Reed stitches are not meant for current draw of the motor. They are used only as a sensor that connects to a low amp control box. Of course you can wire it to control the relays themselves but that's another discussion.
 

Mouthpear

Joined Dec 24, 2018
25
Why are you necroposting to a 4 year old thread?
Why is it that if you post a thread asking a question, you get people complaining and saying that there are already many posts on that subject, but when you go to those posts and comment they complain about bringing up old posts. Go figure.
 

crutschow

Joined Mar 14, 2008
25,702
Why is it that if you post a thread asking a question, you get people complaining and saying that there are already many posts on that subject, but when you go to those posts and comment they complain about bringing up old posts. Go figure.
They are telling you that to get more information.
If you have questions about those old posts then refer to them in your original post, otherwise it gets confusing.

And it's generally bad form to post in old threads, since some of the original posters may no longer be around.
 

Mouthpear

Joined Dec 24, 2018
25
They are telling you that to get more information.
If you have questions about those old posts then refer to them in your original post, otherwise it gets confusing.

And it's generally bad form to post in old threads, since some of the original posters may no longer be around.
I don't see how it is more confusing to keep the information on a single thread than to be jumping back and forth between threads.
Plus I posted information on a thread that wasn't that old and it got move with NO warning. Now when you look at it I doesn't make any sense unless you go back and read the other thread, again that is way more confusing.
 

crutschow

Joined Mar 14, 2008
25,702
Posting your questions on someone else's thread for your own interest is called hijacking a thread, and that's frowned upon here, so that's why you should start your own thread and reference all other threads of interest to your own thread.
That's less confusing for us, if not for you.
 
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