22-03-2014, 10:11 AM
Operational Amplifier Circuits
Aim:
To construct (a) inverting OR non inverting amplifier and perform (b) addition, ©
subtraction (d) integration and (e) differentiation of analog signals using an operational
amplifier (IC 741).
Procedure
1. Make the non-inverting amplifier circuit as shown in fig.5.1. Give a d.c. input of say 2 V
and measure V0. Repeat the above step for different R2/R1 ratio and verify the function of
the non-inverting amplifier as a scale changer. Now give a sinusoidal input signal ‘V i’
with frequency 1 kHz and peak to peak voltage 5 V. Trace the input and output signals.
Measure the peak to peak voltage of output signal V0. Repeat for various input
frequencies.
2. Make the inverting amplifier circuit as shown in fig. 5.2. Give a d.c. input of say 2 V
and measure V0. Repeat the above step for different R2 and R1 values and verify the
function of the inverting amplifier as a scale changer. Now give a sinusoidal input signal
‘Vi’ with frequency 1 kHz and peak to peak voltage 5 V. Trace the input and output
signals. Measure the peak to peak voltage of output signal V0. Repeat for various input
frequencies.
3. Make the adder circuit as shown in fig. 5.3. Set V1= +1V and V2=0. Measure the output
voltage. Repeat the measurement for V2 = 1, 2, 3 and 4V. Check the output voltage and
compare it with V0 = -(V1+V2), the theoretical value. Tabulate the experimental output
voltage and the excepted (theoretical) values. Can you construct appropriate inverter
circuit such that the output is V0=V1+V2
4. Make the subtractor circuit as shown in Fig. 5.4. Set V1=0, and measure the output
voltage V0 for V2= 0, ±1, ±2, ±3, and ±4V. Tabulate the input and output voltages.
Compare the measured output voltage with the expected (theoretical) voltage.
5. Connect the integrator circuit as shown in Fig. 5.5. Apply a sinusoidal input signal ‘V i’
with frequency 1 kHz and peak to peak voltage 5V. Trace the input and output signals.
Measure the peak to peak voltage of output signal V0. Tabulate the readings. Repeat the
experiment for square and triangular waves. Repeat for C= 0.047μF and 0.1μF.
Calculate the output voltage theoretically and compare with the experimental data.
6. Connect the differentiator circuit as shown in Fig. 5.6. For sine wave, square wave and
triangular wave inputs Vi (1 kHz and Vpp = 5V), measure the peak to peak output voltage.
Trace the input and output signals. Calculate the theoretical output data