PSpice Simulation of the Potentiometer Circuit

EE446 Report

To: J.A. Svoboda

From:

Date(s): 1/18/08

Introduction: The circuit shown in Figure 1 produces an output voltage, v_o, that represents the quantity indicated by a dial connected to the potentiometer. The dial is connected to an 100 kOhm potentiometer indicates an angle -180 deg < theta < 180 deg. Also, take R_i = 50 kOhm and R_f = 250 kOhm.

Figure 1. Potentiometer circuit.

Conclusion: ...

Results:

1. Figure 2 shows the PSpice circuit that simulates the circuit shown in Figure1.

Figure 2. PSpice simulation of the potentiometer circuit. (Requires modification.)

2. Figure 3 shows a plot of the output voltage versus the input angle obtained using the PSpice simulation of the potentiometer circuit.

Figure 3. PSpice simulation results.(Requires modification.)

Potentiometer Wiper Voltage vesus Input Angle

EE446 Report

To: J.A. Svoboda

From:

Date: 1/16/08

Subject: Potentiometer Wiper Voltage

Introduction: The circuit shown in Figure 1 produces an wiper voltage, v_w, that represents the angle, -180 deg < theta < 180 deg, of a dial connected to the potentiometer.

Figure 1. Potentiometer used as a transducer.

Conclusion: The wiper voltage, v_w, is related to the angle theta by the equation …

Finding: ...

Useful Links

• Semiconductor Manufacturers
• Texas Instruments
• Analog Devices
• National Semiconductor
• Maxim
  

• Google Docs

• Simulation
• PSpice
• intusoft

• Transducers
• Omega
  

EE446 (three-level) Report

EE446 Report

To: J.A. Svoboda

From:

Date(s): 1/8/08

Subject: Angle Measurement using a Potentiometer and Inverting Amplifier

Introduction: The circuit shown in Figure 1 produces an output voltage, v_o, that represents the quantity indicated by a dial connected to the potentiometer.

Figure 1. Potentiometer circuit.

Conclusion: Suppose the dial connected to an 100 kW potentiometer indicates an angle -180 deg < Q < 180 deg. After choosing R_i = ______ and R_f = _______, The output voltage is related to the input angle by v_o = k Q where k = 55.56 mV/degree.

Results:

1. The Thevenin equivalent of the potentiometer circuit is …

2. The inverting amplifier is represented by the equation…

3. Combining Results 1 and 2, the circuit is represented by the equation…

4. (Verification) When Q = 45 deg the expected output voltage is v_o = x. The actual output voltage is v_o = y. x is similar to y because …

5. Simulating the circuit using PSpice confirms that …

Findings:

R1:

1. The open circuit voltage is …

2. The output resistance is …

R2:

1. The op amp is modeled as ….

2. The gain of the inverting amplifier is …

R3

1. Combining R1 and R2, the circuit is represented by the equation…

R4

1. The actual output voltage is v_o = …

R5:

1. Figure 2 shows the PSpice circuit that simulates the circuit shown in Figure1.

2. Figure 3 shows the simulation results.

3. In Figure 3, the output voltage is related to the input angle by v_o = k Q where k = 55.56 mV/degree.

Syllabus

EE 446 Instrumentation

Spring 2008

Catalog Description: EE 446 Instrumentation R-3, C-3

Prerequisite: EE 221 (Linear Circuits) and EE 341 (Microelectronics)

Analysis and design of measurement circuits. Transducers. Nonideal op amps. Measurements errors. Noise. Filter circuits. D/A and A/D converters. (Spring)

Textbook: Op Amps for Everyone edited by Ron Mancini, NEWNES, ISBN 978-0-7506-7701-1.

(Go to http://www.ti.com/, search using keyword: op amps for everyone, the 2^nd entry in the search results is the pdf file containing Op Amps for Everyone.)

Software: PSpice, MATLAB

Instructor: Jim Svoboda, (Office Hours: 1-3 PM MWF , CAMP 156, 268-6551, svoboda@clarkson.edu.)

Objectives: Students will be able to

1. analyze and design resistive op amp circuits.
2. analyze and design active filters.
3. account for op amp nonidealities in the analysis and design of op amp circuits.
4. analyze and design measurement circuits using a variety of transducers.
5. use PSpice to analyze measurement circuits.
6. write a "3 level" report
   

Evaluation methods: Homework will be assigned, collected and graded…