Skip to main content

Lab 2: Practical Voltage

Lab 2: Practical Voltage and Current Measurement

Introduction

In this lab assignment, we will experimentally explore the behavior of non-ideal meters. The experiments in this assignment illustrate the effects of non-ideal voltage measurements.

Procedure

1) Construct the circuit below. Measure the voltage V-out using the DMM. Estimate the internal resistance of the voltmeter.

2) Take a picture of the circuit and include in blog.
3) Repeat the test of part (1), except use the voltmeter on the Analog Discovery module to measure V-out. Estimate the internal resistance of the scope instrument.

Analysis


1. Provide the expected output voltage for both ideal and non-ideal voltmeters, based on your pre-lab analysis.

2. Provide a circuit schematic below; include measured resistance values on your schematic.

3. Provide your measured output voltage and your estimated value of the internal resistance of the voltmeter of your DMM. Comment on your results, especially relative to the effects of the voltmeter on the quantity being measured.

4. Provide your measured output voltage and your estimated value of the internal resistance of the voltmeter of your Analog Discovery. Comment on your results, especially relative to the effects of the voltmeter on the quantity being measured.

Conclusion

Very large resistors are used in the voltage divider circuit above. Due to these large resistances, measurement of the voltage V out will likely result in measurement errors due to non-ideal voltmeter effects. It can be seen that if R>>Rm, R eq and the measured V out will be essentially the same as the idealized V out. If R>>Rm is not true, the voltmeter’s internal resistance can have a
significant change on the voltage being measured.

Comments

Popular posts from this blog

Lab 1: Solderless Breadboards, Open-circuits and Short-circuits

Lab 1: Solderless Breadboards, Open-circuits and Short-circuits Introduction: The purpose of this lab assignment is to provide users with an introduction to some of the equipment which will be used in subsequent lab assignments. We used breadboards and digital multimeters(DMM) to complete the lab activity. We examine the connections between different holes in a breadboard using a DMM as an ohmmeter. We see which connections correspond to open circuits and short circuits. We also use jumper wires to change the connectivity between holes on the breadboard. Procedure: 1. Using your DMM as an ohmmeter, connect the leads of the DMM to two holes in the same row on your breadboard. DMM measuring 0.5 Ohms. 2. Check the resistance between two rows of holes on opposite sides of the central channel of the breadboard. DMM measuring 1 Mega Ohms. 3. Check the resistance between two arbitrary holes (not in the same row) of your breadboard. DMM measuring 1 Mega Oh...

Lab 5: Mesh Analysis

Lab 5: Mesh Analysis Introduction In this assignment, we  will use mesh analysis to predict the circuit behavior prior to building and testing the circuit. We will then compare the  measured circuit response with our expectations based on our analysis.  We wish to  determine the voltage differences V 1 and  V 2 . Procedure 1. Construct the circuit below; measure and record all actual resistance values. Measure the voltages V 1 and V 2 in the circuit. Calculate a percent error between the measured voltages and your predictions. 2. Take a picture of your completed circuit. Analysis 1. In the space below, provide a schematic of the circuit, labeled with meshes and values for mesh currents as determined in the pre-lab. Provide estimates for the voltages V 1 and V 2 , based on your mesh currents. 2. In the space below, provide a schematic of the circuit being testing, including measured resistance values. 3. Provide your measured values for the vol...