The Energy Transfer - Thermoelectric circuit board helps students better understand heat engines and heat pumps. Using a Peltier device, cooling and heating effects can be observed and measured using PASCO probeware. In addition, a cooling fan, heat sink and foam insulation can be used to determine their effect on the heating and cooling of the Peltier device.
How It Works
Heat Pump: A Peltier device is constructed of two ceramic plates with p and n semiconductors in between. As DC current is passed through the device, one plate warms and the other plate cools. The temperature is monitored real-time using a thermistor in the aluminum blocks on each side of the Peltier device. In addition, the voltage across and current through the Peltier device can be measured with a Current and Voltage Sensor.
Heat Engine: Once a temperature difference is created in the Peltier device, students can move the knife switch to the heat engine position. Using the temperature difference across its plates, the Peltier device now generates current as the plates move to an equilibrium temperature. The current and voltage generated by the Peltier device can be used with the output load resistors to determine the energy generated. The generated energy can be compared to the input energy to determine appropriate efficiencies. Furthermore, the effects on efficiency when changing the load resistance or temperature difference between the plates can be examined.