Lab Handout

Title: The effect of temperature differential on voltage using a Peltier Device.

Purpose: To see that the electricity generated by a Peltier Device increases as the input temperature differential to the device increases.

3. Background:

The Peltier Device was developed by French physicist Jean Peltier in the early 1834. The device uses the convergence of temperature differential translated to electric current. It is most commonly used for cooling devices ranging from portable coolers to military grade electronics.

This is relevant in sustainability because it helps increase energy efficiency. It does this by increasing the total energy output from a given input. For example, burning one gallon of gasoline creates X amount of energy. Not all of X goes directly into powering a motor, however. Some of it becomes heat. That heat can then be used to power a Peltier Device. Now you have produced more usable energy than you would have from that initial X amount of gasoline. The electricity from the Peltier Device could be used to power some other part of the car, ultimately saving energy.

4. Procedure:

Setup:

1. Place two Styrofoam cups next to each other.

2. Fill one with hot water, preferably from a coffee machine or tea pot (close to boiling).

3. Fill the other one with cold water, preferably adding ice and salt. The Peltier Device should fit inside of two pieces of metal.

4. There should be silicon, for adhesive and heat conducing purposes, on each side of the device.

5. The metal pieces should be bent/curved/shaped so they can each fit int one of the cups, and be joined by the device at the top.

6. Connect the two wires from the Peltier Device  to a voltage reader.

7. Connect the voltage reader to the Lego MindStorm device via cords (that look like phone lines).

8. Also connected to the MindStorm device should be two thermometers. Each should be placed in one of the cups.

9. The MindSorm Device should connect to Labview via a USB cable.

10. In Labview it is necessary to create a program to take the right measurements. The program should simultaneously record the voltage from Peltier Device and both temperatures.

11. Run the program so that it takes from 20-30 measurements.

12. Take the average of the voltage measurements and record them in the appropriate space.

13. Do the same with temperature differential. Allow some time to pass for the temperature differential to decrease. You can add ice to the hot water, or vice versa to speed the process.

14. Continue to run the program and record the measurements 2-3 more times.

15. Then graph the averages with the X-axis being temperature differential in Degrees F and the Y-axis being voltage generated.

5. Data:

6. Analysis:

Graph the average voltage as a function of temperature differential. (X-axis is temperature differential and Y-axis is Voltage).