MATHEMATICAL OPERATIONS USING OP-AMP Lab 06

Green University of Bangladesh

Faculty of Science and Engineering

Department of Electrical and Electronic Engineering

Program: B.Sc. Engg. in EEE

Course Title: EEE 2210 Electronics Lab

Course Credit: 1.5, Prerequisite: EEE 2105, EEE 2209

Experiment No: 09

NAME OF THE EXPERIMENT:  Mathematical OPERATIONS USING OP-AMP

Objective

Any kind of mathematical operations can be done using OP-AMP. In this experiment only three i.e. addition, differentiation and integration operations will be performed.

Theory

The property of infinite impedance and infinite gain of an operational amplifier results in a situation of zero voltage between the two input terminals. The effect is known as a virtual ground. Due to this effect, the op-amp can be used to perform some mathematical operations.

      Addition:   Using the concept of inverting amplifier, the op-amp can be used as an adder     (actually inverting adder) to sum up some input signals. In Fig.1 the output of the op-amp is

V₀ = - (E₁ + E₂ + E₃ )

 

 Adder circuit

                                                                                                             

Integration and Differentiation:  The circuit in Fig. 2 acts as an integrator where the output
 voltage is given as:

Integrator circuit

     Similarly, the circuit in Fig. 3 acts as a differentiator and the output voltage is given as:

 

Different circuit

                          

Apparatus

Trainer board                  1 Capacitor 10mF

OP-AMP (741)               1 Oscilloscope

Resistance                      50kW, 10kW, 20kW

Procedure

1.      Implement the adder circuit as shown in Fig.1. Apply the supply voltages as +12V and        -12V at pin no. 7 and 4 respectively. Apply the input voltages E₁= 2V, E₂= 3V and E₃= 4V, and measure the output voltage.

2.      Implement the integrator circuit as in Fig. 2.

3.      Apply a sinusoidal waveform of 5 volt p-p in the input. Observe the output.

4.      Change the resistance to 50kW and observe the output voltage wave shape.

5.      Repeat step 3 and 4 for a square wave input signal.

6.      Repeat step 3 and 4 for a saw-tooth input signal.

7.      Implement the differentiator circuit in Fig. 3.

8.      Repeat steps 3 to 6.

Report

1.      Draw the input and output waveforms of the integrator and differentiator circuit.

2.      Design a circuit which will take two inputs v₁(t) and v₂(t); producing an output of v₀(t) = 0.5v₁(t) +20óv₂(t)dt.