TEC Can Cooler
By:
Dominic Jenevein, Ian Nation, Scott Rickels
Acknowledgments:
Professor Chang-Siu (ET)
Professor Tsai (ME)
Erin Cole (California Maritime Academy Makerspace)
Chris Mulhauser (California Maritime Academy Makerspace)
Idea:
We wanted a way to take a room temperature beverage and use electronics to cool it down. We Used a Thermoelectric Cooler, heatsinks, and fans to transfer heat from the can to the outside space. This TEC unit was purchased on amazon and came pre-assembled. We use a simple wooden box to house these components and create a cooler box for the can. We also used an Arduino to control the TEC as wells as a perfboard and a custom PCB board made. The wooden housing box was made with half-inch plywood and can be made any way you desire. The TEC uses a 12V 10A power supply. We also used the PCB board positioned in front of the heatsink fans in order to cool the transistor down.
Project Videos:
Downloads
Supplies
The Supplies consisted of:
- A pack of wire jumpers
- LAFIN Project Super Starter Kit
- Contains many components needed such as;
- Arduino UNO
- Thermometer
- NMOS transistors
- Breadboard
- Perfboard
- Contains many components needed such as;
- 12V Semiconductor Refer Cooler
- 12V 10A Power Supply
- Plywood
- Screws
- Solder and Solder Iron
Constructing Box and Circuit
Box Construction:
The construction of the TEC housing Is simple. We simply made a plywood box that can be done any way you like. We attached CAD files to show the sizes of the beards we used but they were sized large enough to be able to securely fit the TEC inside with minimal movement. For anyone recreating this project, you can build the housing and cooling box any way you like and we encourage you to be creative in it.
Circuit
The circuit is a bit more in-depth. We have a full Circuit diagram attached but you will need to know a few more things. This circuit can be done on a breadboard but I would highly recommend that you either solder it or learn to solder it.
As part of the circuit be made a printed circuit board (PCB) for our transistor go on so that it could be separated from the perf board and be in a different location. With the current being drawn through it, the transistor had a tendency to heat up quite a bit. In order to solve this. the PCB was placed in front of the heat sink fan to air cool it. This did solve the problem and helped us arrange out transistor leads effectively.
We were unable to attach the files to print this but if you have the option to make your own PCB then I would definitely recommend it to fight the heat build-up in the transistor.
As for the rest of the circuit, it was all done on a simple Perfboard where we soldered all the connections too. We then ran the Pin leads from the perf board to the Arduino and inserted them. we also had an LCD Screen where we inserted the power leads to the perf board and the signal leads to the Arduino.
Coding the Arduino
The coding for this project is a very important part of it and We have included the actual coding and pseudocode in an attached file so you don't have to do it yourself. However, for those who may not understand it, we have also attached state machine diagrams to demonstrate how each button changes the activity of the TEC.
We have 3 main states:
- Adjusting Setpoint Up or Down
- Adjusting Threshold Up or Down
- The active State where Actual Temperature and Setpoint are displayed
These 3 states work in a loop with 3 buttons. An up adjustment, a downward adjustment, and a next page button. The third photo in this gallery had a diagram of how that would look on the LCD screen and how that operates. In addition to this, it is important to note how the Setpoint and Threshold controls work. The setpoint is the general goal that the TEC and coding want to achieve while the threshold is the acceptable range for the temperature to be within before the TEC will turn back on. For this please reference the 4th photo in this gallery which is a graph that may help.
Power Calculations
Here in this file, we see that the Voltage and current from the power supply will not overload the circuit.
Conclusion
This project isn't the most efficient and we have a few ideas that could be used to make it cool better. A water cooling loop was something we had considered in the beginning but couldn't afford but would make the project cool a lot better than this implementation does. If we would have to do it over again we would work to implement a water cooling loop.
We also have suggestions for anyone attempting this project. We would recommend triple-checking the soldering connections and circuit lineup. most of the troubleshooting problems we experienced were caused by simple soldering mistakes and shorts between connections.
If you do this project at home, we urge you to be creative with it and to always practice safety.