So I'm trying to obtain direction on a project. It has a 12v 2.2ah battery pack that's then connected to an Arduino board, thermocouple, thermoelectric cooling unit, and 5 5v fans. I just want to have some direction on how to wire and code all of this together. So I want the system to measure a temperature spot with the thermocouple and there will be a range in the temperature must stay in. If it gets too warm ie 60 degrees Fahrenheit then it will cut on the thermoelectric cooler and 5v fans to then cool the area.
Why a thermocouple? Why not thermosensor (one with 3 legs)?
Make small steps.
Start with the thermometer, add the rest later...
A 12V 2.2A will drain pretty fast with a thermoelectric cooling unit (unless it is very small).
You will need a relay board to control the fans and cooling unit. Or mosfets.
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Show your circuit diagram (no fritzing thankyou) and your code.
Sorry for the delayed response. I'm a college student doing a design project that requires 5 fans and thermo sensors(or temperature sensors, I'm not too sure yet), and finally a thermoelectric cooling unit. I have decided for the battery pack to be 24v 3.3ah and the batteries have a discharge up to 27c. I have the links at the bottom. I have a good idea of how to make the circuit using a 24-volt 4-port relay module and wiring. Also, I don't have access to a circuit diagram maker for Arduino either. I just need help with the code and matching out the longevity of the battery. Because I want the thermo-electric Peltier cooling unit to be on until it reaches 40 degrees Fahrenheit and then turn off. Then when it reaches 50 degrees Fahrenheit it'll cut back on. Thank you for your time!
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Correction my group leader has decide to go with two thermocouple probes
Would a thermosensor work better than a thermocouple?
Lastly here is the thermocouple to be used and were using two of them.
A typical single Peltier element draws about 5 Amperes at 12V, so a 2.2 Ah battery pack will provide at most 30 minutes of cooling time.
But your Peltier unit is only for 12 volts. What are you using to reduce the voltage of the battery pack?
24v relay. Is that okay or do i need a dc to dc converter to bring it down to voltage?
Thermocouples require a reference couple. And connectors of the same materials as the thermocouple. They are expensive.
They are rarely used below 100 deg C. Some can be used up to very high temperatures. Those are still in use. Thermocouples are also used for safety applications as they can generate electricity to open up a valve (in gas heaters).
I do not see why you would not use a ntc of 10 kOhm.
Way more simple...
Thermo sensors might give more accuracy or lower power use (I am not sure). You may also consider a module that sends a digital output (RS-×××). Then you would not have problems with pickup of electrical noise in case of industrial invironment and long wires.
Do you have a good reason to suddenly decide your original 12 volt system should new be powered by a 24 volt system?
How would a relay bring down the voltage???
I honestly dont know. thats why im here to get guidance.
When i did the math by adding all of the watts in the system i felt like the 24v system would give me an hour of operation time. Which it did voming out to 1.02 hours of operation time.
Did your math include running a 12 volt Peltier device at 24 volts? Instant death for the poor old thing!
So should i just increase the amp hours of the battery pack?
That would be a reasonable solution! Also be sure you have one or two spare Peltier devices. They have many diodes in series and it takes only one to open up to destroy the entire device. I think I went through 3 before I got my first Arduino project to work.
I can obtain two more Peltier devices.
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