Automatic chicken door

Thunderbird2

Hi guys , hope this is the right forum .
I've automated my chicken coop door using a spring to pull the door open and an old drill motor attached to string to pull it closed . I have limit switches and it's closing fine but opening way to quickly .
Is there a resistor or some sort that can be attached to slow the motor when opening ? It's powered off a 12 v battery or sometimes a 12 v trafo .

M cebee

robbie will prob know if he's about:D

meercat

love to see this
any chance of a video?

Thunderbird2

If I new how to get one up I would !!
It's handy as its on a timer to keep the rooster in till ten !

crasy dash

You thought of everything there haha I like it

Thunderbird2

Well I didn't want to pay €100 + for one
The motors on its own power supply . The relay is powered by a transformer plugged into a timer ( I have to swap this with a dusk till dawn timer that closes it at dusk and opens it 9 hours later ) . Timer turns on and the relay switches over and the door closes.

meercat

Thunderbird2 wrote: »

If I new how to get one up I would !!
It's handy as its on a timer to keep the rooster in till ten !

pics then

go on ,we need to see it

Thunderbird2

If I put a vid on YouTube will a link work ?
How do I post pics???

DublinDilbert

Can you get a 6v trafo to run the motor? Or maybe 8v?

A resistor will also work, but it will need to be a power resistor which can handle enough power.

Thunderbird2

12v is needed to close the door due to the spring .

meercat

Thunderbird2 wrote: »

If I put a vid on YouTube will a link work ?
How do I post pics???

yeah link will work

DublinDilbert

Ahhh ok so you just need to slow it in one direction only.

I would guess you need to look at your spring again. The spring should be there to counter balance the weight of the door / flap. Then the motor has roughly the same effort in each direction.

Bruthal

Thunderbird2 wrote: »

Well I didn't want to pay €100 + for one
The motors on its own power supply . The relay is powered by a transformer plugged into a timer ( I have to swap this with a dusk till dawn timer that closes it at dusk and opens it 9 hours later ) . Timer turns on and the relay switches over and the door closes.

So when the drill motor pulls it closed, a limit switch opens to stop drill motor when the door is closed all the way?

How does it then open it? Reverse the drill motor to release string, and spring pulls open?

As others said, running it with 6v or another suitable voltage will slow it.

Or making the drill motor pulley with the string on it smaller, and/or move the attach point to the door further from the hinge.

2011

Or you could leave it as it as it is as make chicken McNuggets :D

deandean

Ha i made one of those about 20 years ago. I used an old Venner or Veeder Root electromechanical timer that adjusted itself for daylight hours, (used to be used for street lights).

But I used a geared motor, it took about 30s for the door to open/close.

liveandnetural

food!!!for tought on the old chicken door

http://www.chicken-house.co.uk/acatalog/Automatic_Door_Openers.html

Thunderbird2

liveandnetural wrote: »

food!!!for tought on the old chicken door

http://www.chicken-house.co.uk/acatalog/Automatic_Door_Openers.html

Those prices are the reason I made my own . They don't lock the door either which is a let down because of the prices .
When mine is closed its locked up fairly tight

whizbang

you need a resistor in series in the circuit for open, put a diode parallel with resistor in the forward direction to close.
You'll need a serious diode, salvage the big one from an old computer power supply. maybe try 4-8ohm 10Watt resistor. better still, get a bunch of 1ohm 2W, and add or subtract as needed.

Thunderbird2

I got it sorted I made an articulated type arm and attached it to the drill motor .
Door opens fast but doesn't have enough force to cause damage .
Now the door isn't affected by winds :-)
Vid coming soon

Thunderbird2

http://m.youtube.com/watch?v=SEFFMmGZ86c

Here's a vid

meercat

Thunderbird2 wrote: »

youtube.com/watch?v=SEFFMmGZ86c

Here's a vid

just edited your link here(yours didnt work)
thanks for posting

Thunderbird2

Oh il post another

Bruthal

Thunderbird2 wrote: »

Oh il post another

Here you go.

https://www.youtube.com/watch?v=SEFFMmGZ86c

And here is a timer for it

Thunderbird2

Haha it works on a timer . The timer turns on a trafo for the DPDT relay .the motor has its own power supply

Bruthal

Thunderbird2 wrote: »

Haha it works on a timer .

I know, thats my home made plywood timer

The timer turns on a trafo for the DPDT relay .the motor has its own power supply

A DPDT relay for polarity reversing perhaps.

Bruthal

An interesting one would have been to use a microcontroller chip to output a pwm that counts up and then down for the on to off ratio, each time the relay changes over, so giving a soft start and also a soft stop. Any speed could be programmed in for the door movement.

Output it through a power transistor then, to drive the battery drill motor.

Thunderbird2

robbie7730 wrote: »

An interesting one would have been to use a microcontroller chip to output a pwm that counts up and then down for the on to off ratio, each time the relay changes over, so giving a soft start and also a soft stop. Any speed could be programmed in for the door movement.

Output it through a power transistor then, to drive the battery drill motor.

Do you have any links or diagrams for this method ??
I'm making another one using a door that slides up and down for a family member .

Bruthal

Thunderbird2 wrote: »

Do you have any links or diagrams for this method ??
I'm making another one using a door that slides up and down for a family member .

Well i have made the circuits myself in a couple of items, and then have to write up a program to run on the chip. I did this for soft starting of dc motors, and am going to do one for the car fan heater motor for selectable speeds, which has blown its resistor pack and will only work on full speed at present:D

But a 555 timer chip can also be used to make a pwm circuit, with a control pot to set the speed. It wont have a soft start but a variable speed setting that you can manually set will do perfect for your applications. The chip then has its output switching a transistor in the pwm pattern, which can then switch the motor.

Look up 555 pwm circuits.
Here is one anyway

You can see the irf540 mosfet which is a power transistor. It will switch the negative leg of the load being switched, as seen in the diagram.

I used a very similar circuit for manual control of radio control servos in a project a couple of years ago. But have since went the microcontroller route. But that 555 chip setup might do the job.

EDIT. IRF520 in that diagram, I used IRF540N ones in a few applications. It depends on the motor load.