I recently discovered the peltier modules, and how they could be used to "detect" cloud coverage in the sky, IR radiance balance, etc.
So, these post is to ask to the experts which one of the availables could be used without fried it... in what characteristics i should take into account to connect it to arduino?
On the other hand, they should came with only two wires? So, how should i connect them? digital/analogical, input/output,.. ???
So many questions, i know, but i am completelly lost.
If we're thinking of the same thing, a Peltier Module uses electricity to create a heat pump across a semiconductor material (and vice versa). This is referred to as the Peltier effect.
Thanks TchnclFl for your fast reply and also for the link.
Cool! I saw in your link that they could be also used in heating and cooling! Great applications. I had on mind meteorological applications, but it will open my mind about other ideas!
I have no idea how you could use this for meteorological purposes to be honest :o. Are you considering putting it in the sun and hoping that one side will heat up more than the other enough to determine how cloudy it is based on the voltage produced?
It seems like that would be ineffective, when you could just use a photocell or equivalent to do the same.
Yeah! the cloud detection in a little bit less efective, and it is mainly used during the night period, when there is not sun radiation incomming. There are commertials sensors that use this effect. I will try to locate links to examples to post here.
On the other hand, there is other application what is relate to IR radiation measurement coming from the atmosphere and from the surface (what is also related to what kind of materials we have there: type, grain size, texture, color, etc.). It depends of could coverage, sun intensity depending of the time and day along the year,.... I will also try to locate here examples of commercial devices using this effect.
However, they could be used, i think to calculate solar radiation all around the day too.
In any case, about my question about how to wire the module to arduino for sensing, the idea is that a difference in temperature in each plate produces a voltage, so may be connecting one of the wires to GND and the other to analog pin of arduino it could be possible to read this voltaje. Is it right? could it need a pull up resistance?
On the other hand, my seconds question is still there, which one could i use without to burn the arduino?
May be you guys that use this module could give me some information about what you have...
Thanks!
the idea is that a difference in temperature in each plate produces a voltage,
No that's not how it works. All you do is pass current through it and it transfers heat from one plate to the other. The direction of heat travel is governed by the direction of current. Just treat it like a load. They take quite a lot of current in the 2 to 10 A region. If you want bi-directional current then use a H-bridge the same as you would for motors.
It is, in effect, a collection of thermocouples so in theory it will produce a voltage when there is a temperature difference between the two plates. However, this is not the mode it is normally used in. I think the voltage produced will be in the order of mV per degrees C so if you are using it like this you will probably need an amplifier before you can read it from the arduino.
Well actually they can work that way as well, through the seebeck effect. But there are other elements that are designed to be more effective (can't remember their name just now)
I didn´t have time to made my own experiments with the peltier module, but one dude did his own. Check it if you are curious about how to use the peltier module to detect clouds:
But this module if effective during the night, not during the day...
Cheers,
