Google Search

Monday, April 4, 2011

INTEGRATOR


INTEGRATOR

Obtain the output of an Integrator circuit with component values R1Cf = 0.1ms, Rf = 10 R1 and Cf = 0.01 µF , if 2 V peak to peak square wave at 1000Hz is applied as input.

AIM:

To design an Integrator circuit for the given specifications using Op-Amp IC 741.

APPARATUS REQUIRED:

S.No
Name of the Apparatus
Range
Quantity
1.
Function Generator
3 MHz
1
2.
CRO
30 MHz
1
3.
Dual RPS
0 – 30 V
1
4.
Op-Amp
IC 741
1
5.
Bread Board

1
6.
Resistors


7.
Capacitors


8.
Connecting wires and probes
As required


THEORY:

A circuit in which the output voltage waveform is the integral of the input voltage waveform is the integrator.  Such a circuit is obtained by using a basic inverting amplifier configuration if the feedback resistor Rf  is replaced by a capacitor Cf .  The expression for the output voltage is given as,

Vo = - (1/Rf C1) ∫ Vi dt

Here the negative sign indicates that the output voltage is 180 0 out of phase with the input signal.  Normally between fa and fb the circuit acts as an integrator.  Generally, the value of fa < fb .  The input signal will be integrated properly if the Time period T of the signal is larger than or equal to Rf Cf.  That is,

T ≥ Rf Cf

The integrator is most commonly used in analog computers and ADC and signal-wave shaping circuits.








PIN DIAGRAM:



CIRCUIT DIAGRAM OF INTEGRATOR:




DESIGN:


We know   the frequency at which the gain is 0 dB, fb = 1 / (2π R1 Cf)
Therefore fb = _____
Since fb = 10 fa, and also the gain limiting frequency fa = 1 / (2π Rf Cf)
We get, Rf = _______   and hence R1 = __________

PROCEDURE:

  1.  Connections are given as per the circuit diagram.
  2. + Vcc and - Vcc supply is given to the power supply terminal of the Op-Amp IC.
  3. By adjusting the amplitude and frequency knobs of the function generator, appropriate input voltage is applied to the inverting input terminal of the Op-Amp.
  4. The output voltage is obtained in the CRO and the input and output voltage waveforms are plotted in a graph sheet.

OBSERVATIONS:

S.No.
Amplitude
( No. of div x Volts per div )
Time period
( No. of div x Time per div )
Input


Output




MODEL GRAPH:
























RESULT:

The design of the Integrator circuit was done and the input and output waveforms were obtained.

0 comments:

Post a Comment