MATC EXPERIMENT 27 MAXIMUM POWER TRANSFER

Transcription

1 MATC EXPERIMENT 27 MAXIMUM POWER TRANSFER Submitted to: Mr. Sutterfield Submitted by: Jody Decker Submitted on: XX Performed on: 2/27/08 Lab Partner: None

2 TABLE OF CONTENTS THEORETICAL SOLUTIONS AND FORMULAS... 1 RESULTS FOR EXPERIMENT QUESTIONS FOR EXPERIMENT

3 Page 1 of 6 THEORETICAL SOLUTIONS AND FORMULAS E1 12 V R1 1k Ohm Fig 27-1 Test Circuit 1 Ref. Table 27-1 R1 1k Ohm R3 470 Ohm RL A Sample Calculations for Fig 27-2 Test circuit 2 Ref Table 27-2 R 1 R2 R ( ) TH = RAB = R3 + R1 // R2 = R3 + R1 + R2 1kΩ 220Ω RTH = 470Ω + = Ω 1kΩ + 220Ω E1 12V V TH = R2 = 220Ω = 2. 16V R + R 1kΩ + 220Ω 1 2 E1 12 V R2 220 Ohm Fig 27-2a Test Circuit 2 R1 1k Ohm R3 470 Ohm R2 220 Ohm B A RL Calculations at max power, R L =R TH = Ohm VTH VRLTH = RLTH R + R V I RLTH TH LTH 2.16V = Ω = 1.08V Ω Ω VTH 1.08V = = = 1. ma R Ω RLTH 66 LTH 2 2 V 1.08 P RLTH = = = 1. 66mW R Ω Fig 27-2b Finding R TH (R AB ), source set to zero, R L removed B R1 1k Ohm R3 470 Ohm A Rth Ohm A E1 12 V R2 220 Ohm E V RL Fig 27-2c Finding V TH (V AB ), R L removed B Fig 27-2d Thevenin Equivalent Circuit B

4 Page 2 of 6 RESULTS FOR EXPERIMENT 27 Table 27-1 Data For Schematics 27-1 Potentiometer and Fixed Resistors as the Load with a DC Source Nominal Resistance in ohms Resistance in ohms % diff RT for pot settings RP1 to RP10 and fixed RT for pot settings RP1 to RP10 and fixed resistors in resistors in ohms ohms % diff Voltage on Loadt in Volts Voltage on Volts % diff Current on amps Current on Pot in amps % diff Power on Power on Pot in watts Pot in watts % diff R NA NA NA NA NA NA NA NA NA NA NA NA Rp E-3 NA 12.00E E E E-3 NA RL E E E E RP E E E E RL E E E E RL E E E E RP E E E E RL E E E E RL E E E E RP E E E E RL E E E E RP E E E E RL E E E E RL E E E E RP E E E E RL E E E E RP E E E E RP E E E E RL E E E E RP E E E E RP E E E E RP E E E E E RL E E E E E1 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A

5 Page 3 of 6 Table 27-2 Data For Schematics 27-2 Potentiometer and Fixed Resistors as the Load with a DC Source Nominal Resistance in ohms Resistance Percent in ohms Diff RT for pot settings RP1 to RP10 and fixed resistors in ohms RT for pot settings RP1 to RP10 and fixed resistors in ohms Percent Diff Voltage on Volts Voltage on Volts Percent Difference Current on amps Current on Pot in amps Percent Diff Power on Power on Pot in watts Pot in watts R N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A R N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A R N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A RP N/A E-6 NA 3.33E E E E-6 NA RL E E E E RP E E E E RL E E E E RL E E E E RP E E E E RL E E E E RL E E E E RP E E E E RPMAX E E E E RL E E E E RP E E E E RL E E E E RL E E E E RP E E E E RL E E E E RP E E E E RP E E E E RL E E E E RP E E E E RP E E E E RP E E E E E RL E E E E E1 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Percent Diff Sample Calculations from Results Ref Table 27-2 Percent difference NV MV 1000Ω 991Ω PD = = 100 =.90% NV 1000Ω PD = Percent difference NV = Nominal value MV = value power P = V I = 288mV 2.88mA RL 1 RL1 RL1 = 831.7µ W

6 Page 4 of E E-3 Graph 27-1 Maximum Power Transfer Test Circuit 1 Jody Decker MATC 2/27/2008 Load Power in Watts 30.00E E E E E E E Load Resistance in Ohms

7 Page 5 of E-3 Graph 27-2 Maximum Power Transfer Test Circuit 2 Jody Decker MATC 2/27/ E E-3 Load Power in Watts 1.40E E E E E E E E Load Resistance in Ohms

8 Page 6 of 6 QUESTIONS FOR EXPERIMENT Calculate the power dissipated for each potentiometer setting in step 1. Plot the power on the Y-axis and potentiometer setting on the X-axis. On the same graph, plot predicted power and measured power versus load resistance of the fixed resistors for step 2. Explain any significant differences. There were no significant differences between the graphs for calculated and measured values. 3. Is there a difference in circuit behavior between applying the AC source and DC source? Explain. The condition at which maximum power transfer occurs would be the same for an AC souce as it would be for a DC source because resistance opposes alternating current in the same way it opposes direct current and power is determined by the same equation P = V I. 4. Would maximum power transfer hold true for loads with reactance? Explain. Yes, in an AC circuit, reactance is the same as resistance in it s opposition to current flow. For loads with reactance, the source impedence would need to match the load impedence in the same way that the source resistance must match the load resistance. 5. What is the trend in power transfer versus load resistance? The maximum power that can be transferred between a source and load will happen when the load resistance or impedence matches that of the source. As the difference in values for source and load resistance become greater, the amount of power that can be transferred is lowered.