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, vo, 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 Ri = ______ and Rf = _______, The output voltage is related to the input angle by vo = k Q where k = 55.56 mV/degree.
Results:
The Thevenin equivalent of the potentiometer circuit is …
The inverting amplifier is represented by the equation…
Combining Results 1 and 2, the circuit is represented by the equation…
(Verification) When Q = 45 deg the expected output voltage is vo = x. The actual output voltage is vo = y. x is similar to y because …
Simulating the circuit using PSpice confirms that …
Findings:
R1:
The open circuit voltage is …
The output resistance is …
The op amp is modeled as ….
The gain of the inverting amplifier is …
Combining R1 and R2, the circuit is represented by the equation…
The actual output voltage is vo = …
Figure 2 shows the PSpice circuit that simulates the circuit shown in Figure1.
Figure 3 shows the simulation results.
In Figure 3, the output voltage is related to the input angle by vo = k Q where k = 55.56 mV/degree.
No comments:
Post a Comment