PASCO ET-8782 Energy Transfer– Thermoelectric - Manual (Page 17)

Model No. ET-8782 Energy Transfer –Thermoelectric
17 ®
Experiment 2:
Load Resistance and Efficiency
Introduction
In this experiment you will examine the relationship between output load resistance and the
power generated by the peltier when it is operating in heat engine mode.
You will observe the output power as you vary the load resistance while keeping everything else
constant (the temperature difference between the blocks, for instance). Since it is not possible to
hold the blocks at a steady temperature difference, you will take the peltier through several
identical cycles of heating and cooling, and measure the power each time a certain temperature
difference occurs. You will repeat the cycle for each value of load resistance that you test, ranging
from slightly over 0
Ω to 30 Ω.
Before you start, predict what you will discover about the relationship between output power and
load resistance. Record your prediction using words, numbers and a graph. Explain your
reasoning.
Set-Up
1. Input Power: Set the Heat Pump/Heat Engine switch to the neutral position (straight up).
Connect the power supply using banana patch cords to the input power terminals on the
circuit board as shown in picture. Note the polarity.
Equipment Required Part Number
Thermoelectric circuit board part of ET-8782
Foam insulators (qty. 2) part of ET-8782
Heat sink and thumbscrew part of ET-8782
Banana patch cords (qty. 6) part of ET-8782
Temperature cables (qty. 2) part of ET-8782
DC Power Supply (10 V, 1 A minimum) SE-9720A or equivalent
PASPORT Voltage/Current Sensor PS-2115
PASPORT Quad Temperature Sensor PS-2143
PASPORT interface(s) PS-2001 or equivalent
DataStudio software See PASCO catalog
“Load Efficiency” configuration file for DataStudio part of ET-8782