led sensor for green house chicken brooder.

[cbiblis]

As i sit here waiting on parts for a new thermostat i thought of a design that might be fun to make, not to mention rewarding. Has anyone noticed that led lights show voltage when exposed to sun light? Different intensities also show different voltages. So i got to thinking about my green house. I also use it for a chicken brooder to save on heat lamp power. Here is my thought: Chickens need feathers to survive in the winter months. For toughs of us that hatch eggs in the winter time, we have to keep the chicks warm until they get there feathers to keep them warm enough to survive.The green house, of coarse, heats during the day. But at night it gets to cold, so i designed a thermostat that when the temp of the green house gets below a certain point the thermo turns on the brooder lamps that i have installed in the green house. The chicks migrate to the lamps and stay warm enough until the sun comes back out. This works well. However, when i was in the green house on a sunny day, i noticed that the thermo had the lights on but i noticed that the chicks were hiding in the shade. I looked at the temp and it was 60 degrees. The chicks would died for sure if they were outside in that temp. So i asked myself, What is the deal? I then surmised that when the sun shined through the green house panels one could feel the heat radiating like a magnifying glass even thou it was 60 degrees in the room. This made me think that i had to revise my design. i got to thinking that if i were to install a light sensor then it would just turn the light off when the sun was out but not account for it's intensity. So i came up with the idea that if one were to design a light sensor using a led and test the voltage at different intensities that one could design a circuit that will know when the chicks would need the light and when one was wasting power. Well, i think this merits exploration. It would be a simple enough project. My question is this. Has anyone done a project similar to this or does anyone foresee any problems with this idea? And of coarse, due to my lack of knowledge on electronics, would anyone like to help with it's design? As for my thermostat i use a LM324n . I only use two of the ampifier outputs leaving two more to incorporate this addition.

 

[Boncuk]

Hi cbiblis,

8mm clear dome red LEDs work perfect for your application. At bright sunlight they produce up to 1.3V. I used them for a solar tracker.

Boncuk

 

[crutschow]

A silicon diode light sensor is more sensitive then an LED and is made for such a task. But if you are sensing sunlight then you are probably not really concerned about sensitivity.

You could use a **broken link removed**to provide a stable voltage reference for a comparator built with one op amp of the LM324. Remember to add some hysteresis to the comparator so it doesn't chatter. The reference voltage goes to one input of the comparator and the other would go to the LED output voltage.

 

[Mikebits]

Hmm, what if the sun is out and bright, but it is a really cold day, like 40deg F? If I were you, I would keep things as you got it and just ensure the chicks can move to enough shade if needed.

 

[cbiblis]

A silicon diode light sensor is more sensitive then an LED and is made for such a task. But if you are sensing sunlight then you are probably not really concerned about sensitivity.

You could use a **broken link removed**to provide a stable voltage reference for a comparator built with one op amp of the LM324. Remember to add some hysteresis to the comparator so it doesn't chatter. The reference voltage goes to one input of the comparator and the other would go to the LED output voltage.

Great link thanks.

 

[cbiblis]

Hi cbiblis,

8mm clear dome red LEDs work perfect for your application. At bright sunlight they produce up to 1.3V. I used them for a solar tracker.

Boncuk

I have about 90 8mm clear dome white light and about 50 8mm clear dome green to play with. i will test them if i can't get the right voltage then i'll order the reds. Thanks for the help.

 

[cbiblis]

Hmm, what if the sun is out and bright, but it is a really cold day, like 40deg F? If I were you, I would keep things as you got it and just ensure the chicks can move to enough shade if needed.

Well if the sun is intense enough then they should be fine. i have checked the green house when it was 8 degrees out in full sun @ 60 degrees. that is the coldest I've ever seen it here. But it does bring up the question how about when the sun first comes up. Maybe i could incorporate a 555 timer into the mix for a delayed reaction. I think solar trackers do this. Thanks for the valuable input.

 

[crutschow]

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