I need help making a light activated circuit for a 12 volt motor

[gayoub]

light activated circuit for 12 volt motor

Hi guys
I need help to make a light activated circuit that comes on when it is light and drives a 12 volt motor. I've had success with one that turns on an LED, but not a motor. Most that i've found turn on at night.
If you know of one for sale, that would be great as well.
Any help would be appreciated.
Novice here.
Regards
George

 

[D.A.(Tony)Stewart]

Re: light activated circuit for 12 volt motor

Can you work with relays?

Can you at least explain what you are trying to control?

 

[gayoub]

Re: light activated circuit for 12 volt motor

I am adding an automatic door for our chicken shed when it is light enough. I have printed some 3D gears that turn a small 12volt motor. I can follow a schematic but pretty much a novice.
Thanks for any help you can provide.
Regards
George

 

[BradtheRad]

Re: light activated circuit for 12 volt motor

A photosensor generates a slowly-changing signal (or slowly-changing resistance). You can feed this signal to a schmitt trigger. The output changes state when the input reaches some threshold level.

Questions:

a) Do you wish the motor to run just long enough to operate the door, then shut off?

b) Do you wish the door to open at sunrise, then close at evening?

 

[D.A.(Tony)Stewart]

Re: light activated circuit for 12 volt motor



Reliable switches are a must, with limit switches in each direction of door travel.

A DPDT relay ( or full bridge) is wired as shown to change directions and a (reliable) low side daylight switch to change directions.

Assuming the door travels to the end to open the switch, then the gear motor turns off.

Do chickens follow sunset curfew rules?

 

[gayoub]

Re: light activated circuit for 12 volt motor

Thanks for that.
The door only needs to open, i will shut it myself.
These chickens are up and cackling at 5am waiting for the door to open (Safety against foxes)
Thanks for your help.
Regards

 

[mjuneja]

Re: light activated circuit for 12 volt motor

You can try using LDR (light detecting resistor) to activate/deactivate SPDT relay which ultimately controls the on-off operation of your 12V motor.

Actually can you just confirm current requirement of your motor?

 

[Kajunbee]

Re: light activated circuit for 12 volt motor

Have you considered letting gravity open the door. If you hinge the door at the bottom you can just use a solenoid type latch. When the solenoid pulls it releases the door and it falls open. The door could double as the ramp into the coup are just lay on top of the existing ramp if the coup is to high off the ground. You could build a frame that angles the door out slightly so that it will fall. Or have a spring that pushes the door outwards a small amount until gravity takes over.

- - - Updated - - -

If you have a full height walk in entrance you wouldn't want to do this. But you could possibly cut a small door into it that would open automatically.

 

[gayoub]

Re: light activated circuit for 12 volt motor

Thanks guys for all your comments and ideas. I have used a LDR with a relay on a 12v motor, as mjuneja suggested. And as Kajumbee suggested, I have cut a small door, just big enough for the chickens. I will be printed some gears on my 3d printer and install it in a day or so. Laziness creates creativity
Still very new to this, but it's an enjoyable challenge.
Signing off.
George