Automatic door with photo sensor and delay(now with video)

[KickenChicken]

So yesterday I was in my home office/ workshop thinking about how to make a automatic coop door closer/opener. I wanted to make something cheap that could both open and close the coop door. The closing is because my wife and I don’t always get home in time to close the door and we don’t always like to get up early on the weekends to open it. I also knew I wanted it to run on 115ac so I don’t have to worry about battery’s or solar panels and there extra expenses The major advantage of my design is you don’t have to set a timer and change it weekly as daylight hours change.

I started designing with the parts that I had around the garage and shop. I went to Fry’s electronics’ to get a photo sensing transistor, plus I needed a couple of pnp transistors and a small relay, the total for all these parts came to about $16 but when I was on the way out I walked by the education and hobby kits and there was a photo sensor with control relay kit for $9 so I got that instead. I had the rest of the parts I had except for the time delay relay, I found a set of three on e-bay for $15 but I only need one for this project. So in all the actual cost of this was around $14. Most of the parts came out of other things. I think if you try and duplicate it without the spare parts it could be done for around $40 if you shop liquidation shops if you went for all new parts I think it could be done for around $120.

Well the basic concept is that the motor will turn on when the sun comes up and open the door then turn off when it hit’s the open limit switch and the door is fully open. Then when it gets dark it will wait 17min then reverse the motor until the door closes and hit’s the closed limit switch.

I have tested the unit on bench without the delay turned on all they way (I didn’t want to wait 17min to see if it worked) and it turned on and shut off when I held the limit switch then I covered the light sensor with my finger and it reversed direction and shut off when I hit the other switch. So all I have left is to finish making a box, sealing it up then seeing if it works on the actual coop.

Let me know what you think
I had to share even though its not 100% done yet

Derrick



Rough schematics

The unfinnished unit

O I forgot to add the motor is geared down 149to1 it is 1/4 Horse Power and spins at 1.5 rotations a second. The extra HP is so I can use heavy springs to keep predators out and it is what I had sitting around.

I just realized I drew the relays energized and they should not be with the limit switch open and both should never be on at the same time if the relay in the photo sensor control is working.

I will add a video once i have it up and running on the coop

Thanks again
Derrick

 

[jus1jack]

Looks like it should work to me.

link to a few others lot of different types on here.

https://www.backyardchickens.com/se...=ISO-8859-1&q=+Automatic+door+&sa=Search#1239

Post some more pics of it in action when ya get it goin.

 

[KickenChicken]

Well here is a video of the opener/closer working on the bench, I still don’t have the time delay working right but I hope to figure it out over the next week and have it working on the coop.



www.bourhenne.com/pics/P8280070.AVI

 

[KickenChicken]

I just checked the video link and found it was not working but it is fixed now
www.bourhenne.com/pics/P8280070.AVI

 

[rebelcowboysnb]

Make sure you put the closing limit switch behind a hinged bar that covers the hole of the bottom of the door so just like a garage door if any part of the leading edge of the door hits anything it will stop till what ever it is moves out of the way. That way you have a safety stop an don't have to add more electronics.

 

[Lensters]

Looks like you got the concepts right. A couple of thoughts:

115V AC through the FWR and that big of cap will produce about 170V DC

Having that high of DC voltage you really want it enclosed in a grounded metal box for safety. That cap contains enough energy to easily kill a person. A small drain off resistor is probably wise.

Electrolytic caps have a limited life span and usually fail in a spectacular fashion, blowing their somewhat toxic contents through their side. Since you are only driving a motor with that power nothing electrically will be harmed but will you be able to contain the contents of the cap when it goes?

My EE senior design project had a DC supply like that and these are the things I had overlooked. Well not the first item, but the second two.

 

[KickenChicken]

Quote:
I did notice the voltage was in the 130v range with the load of the motor, but the motor only needs to run for a few seconds so I dont think the extra 15v should not damage it . I will add the drain off resistor it is somthing that I have not thought of. I am thinking that a heavy duty plastic box might be the best idea but I think that a small wood box that is well sealed should hold the contents of that cap.

I don't have any kind of degree I thought an electrolytic cap have a long life span. considering it is only going to be discharged twice a day It should last years


Thanks for the input
Derrick