As the feedback is tapped to the inverting input the operational amplifier is

# As the feedback is tapped to the inverting input the

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As the feedback is tapped to the inverting input, the operational amplifier is therefore connected to the so called "inverting amplifier" configuration which outputs the needed 180 degree phase shift.
RC oscillations are stable and the RC oscillators produces a well-shaped sine wave with the frequency being proportional to 1/RC and ergo, a wider frequency range may occur when using a variable capacitor . In order to sustain/maintain the oscillations given below, the operational amplifiers gain must be equal to 29.: 𝑅 ? ? ? = − 𝑅 IV. Resources Computer with NI Multisim 13.0installed Components used in Multisim 741Op-Amp Resistors Capacitors Oscilloscope V. Procedure 1.) Open Multisim software 2.) Build the circuit as shown 3.) Connect the positive input of the op-amp to ground. 4.) Connect R5 and R4 in which R5=1.2kohms and R4 is a variable resistor. 5.) Build the RC network. C1=C2=C3 and R1=R2=R3.
6.) Observe the input and output signal using an oscilloscope. 7.) Find the value of R4. Adjust the variable resistor R4 such that the gain would be equal to 29. 8.) Observe the input and output signal again and sketch their respective waveforms such that the input signal is a dotted-signal while the output is a continuous signal. 9.) Calculate for the frequency of the oscillator. 10.) Observe each RC section of the oscillator using an oscilloscope. 11.) With R=R1=R2=R3 and C=C1=C2=C3, Change the values inside the RC network as follows and complete the following table.
Course: Experiment No.: Group no.: Section: Group Members: Date Performed: Date Submitted: Instructor: VI. Data and Results: Wavefor m 1 Table1 Table1
Table2 VII. Observation: VIII . Interpretation: IX. Question and Problems: a. How does the RC stages affect the oscillator? _ _ Frequency Rf A v 2 TRIAL RESIST OR CAPACIT OR FREQUENC Y (CALCULAT ED) 1 1nF 6.5 kHz 2 1kΩ 8nF
_ _ b. Why does it uses 3 RC stages? _ _ _ _ c. What happens when the variable resistor R4 is adjusted? _ _ _ _ d. What is the total phase shift of the circuit?Explain. _ _ _ _ e. Why is it essential to have a unity loop gain and a degree phase shift? Why is it necessary to have Av equal to29? _ _ _ _
X. Assessment (Rubric for LaboratoryPerformance):
CRITERIA BEGINN ER 1 ACCEPTA BLE 2 PROFICI ENT 3 SCOR E I. Laboratory Skills Manipulat ive Skills Members do not demonstrate needed skills. Members occasionally demonstrate needed skills. Members always demonstrate needed skills. Experime ntal Set- up Members are unable to set up the materials. Members are able to set up the materials with supervision. Members are able to set up the materials with minimum supervision. Process Skills Members do not demonstrate targeted process skills. Members occasionally demonstrate targeted process skills. Members always demonstrate targeted process skills. Safety Precauti ons Members do not follow safety precautions. Members follow safety precautions most of the time. Members follow safety precautions at all times.

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