Скачать или смотреть Op-Amp RC Phase Shift Oscillator | Circuit Diagram | Breadboard Wiring | Diploma | BTECH

RC Phase Shift Oscillator | Using Op-Amp | 741 IC | Linear Integrated Circuits Lab Experiments.Engineering | Diploma Polytechnic Students

Aim: To Design and setup a RC phase shift oscillator using Op-Amp 741 and (i) Plot the
output waveform (ii) Measure the frequency of oscillation

Equipments/Components
Sl. No. Name and specification Quantity
1 Dual Power Supply +/-15V 1
2 Resistors 5
3 Capacitor 0.01μF 3
4 IC μA 741 1
5 Oscilloscope 1
6 Bread board 1
7 Connecting wires and probes As required

Principle:
RC phase shift oscillator uses op-amp, in inverting amplifier
mode and the circuit generates its own output signal. It consists of an op-amp as an amplifier
and 3 RC cascaded network as the feedback circuit. Since the op-amp is used in the inverting
mode, any signal that appears at the inverting terminal is shifted by 1800 at the output. An
additional 1800 phase shift required for oscillation is provided by the cascaded RC network.
Thus the total phase shift around the circuit is 3600 or 00 . At some specific frequency, the
phase shift of the cascaded RC network is exactly 1800 and feedback factor is 1/29. If the
gain of the amplifier is 29, the total loop gain of the circuit becomes 1. The circuit will
oscillate at this specific frequency and is given by
f = 1/(2πRC√6)

Procedure:
1. Check the components.
2. Setup the RC phase shift oscillator circuit on the breadboard and check the
connections.
3. Switch on the power supply.
4. Observe output voltage on oscilloscope.
5. Draw the waveforms on the graph.
6. Measure the frequency of oscillation .

Design:

f = 1/(2πRC√6)
Let f = 1 KHz, and C= 0.1μF
R = 680Ω
Gain = 29
Rf/Ri = 29
If R1 = 1.2KΩ ; Rf Use 47KΩ pot

Observations:
Measured frequency of oscillation is =?