To design and simulate a Differentiator circuit and observe output with different input waveforms.

 

 

Function generator, CRO, Regulated Power supply, resistor, capacitor, 741 IC, connecting wires.

 

 

Integrator circuit design has been implemented on the virtual breadboard using following specifications:

·         Power Supply: +10v and -10v

·         Function generator: Selected wave with following specifications:

          Frequency = 45Hz, 50Hz, 55Hz, 60Hz, 100Hz.

          Amplitude: 1,2,3V

          Duty cycle = 50%

·         Capacitor C: 1000nF

·         Resistor R₁: 10.38K

 

 

 

The basic Differentiator Amplifier circuit is the exact opposite to that of the Integrator operational amplifier circuit that we saw in the previous experiment. Here, the position of the capacitor and resistor have been reversed and now the Capacitor, C is connected to the input terminal of the inverting amplifier while the Resistor, R₁ forms the negative feedback element across the operational amplifier. This circuit performs the mathematical operation of Differentiation that is it produces a voltage output which is proportional to the input voltage's rate-of-change and the current flowing through the capacitor. Or in other words the output voltage is a scaled version of the derivative of the input voltage. The capacitor blocks any DC content only allowing AC type signals to pass through and whose frequency is dependent on the rate of change of the input signal. At low frequencies the reactance of the capacitor is "High" resulting in a low gain (R₁/X_c) and low output voltage from the op-amp.

 

 

The differentiator Circuit 

 

 

 

1.     Connect the circuit as shown in the circuit diagram.

2.     Give the input signal as specified.

3.     Switch on the power supply.

4.     Note down the outputs from the CRO

5.     Draw the necessary waveforms on the graph sheet.

 

 

 

1.     Observe the output waveform from CRO.

2.     Measure the frequency and the voltage of the output waveform in the CRO.

3.     Check

 

 

Frequency of the output waveform will remain same and the output voltage can be calculated using above equation and compared with the observed value.

4.     Observe outputs of the differentiator circuit using different input waveforms.

 

 

 

1.     After Clicking on �Open function generator� icon on the left of the Vlab live environment page, set the frequency, amplitude and the type of waveform on function generator.

2.     Select sine wave and then set frequency 45Hz

 

 

3.     Set the peak to peak voltage V_pp = 3v i.e. amplitude = 3v.

 

 

4.     Circuit has been designed on the virtual breadboard with the help of procedure.

 

 

5.     Then on clicking on �Run� icon, the output waveform generated and the input can be observed on the CRO. CRO web page can be opened using icon �oscilloscope� at top left on the live experiment page.

 

 

6.     Click on measure. Then one can observe options like source  select measure

 Click on source and select 4 i.e. the input wave.

 Click on select and select the parameter to be measured for example select frequency or amplitude.

 Click on measure to get the frequency and amplitude of the input waveform.

It comes out to be Frequency: 45Hz, amplitude: 3.13V

 

 

 

 

 

 

7.     Then check the phase difference between the input and the output wave. Follow the same steps as mentioned earlier. Select phase option and get the phase difference. The phase difference comes out to be 97�.

 

 

 

8.     Now observe the amplitude of the output waveform generated. The output voltage come sout to be 8.97V.

 

 

 

 

 

Output of the integrator will be equal to

 

 

 

Hence theoretically, output voltage should be 8.93V and phase difference between input outputs should be 90�.

Experimentally phase difference observed is about 97� and output voltage 9.0V. 

Table representing different output voltages and phase difference at different frequency input waveforms obtained theoretically and experimentally.

Frequency	V0 (Theoretical)	Vo (Experimental)	Phase Diff (Th.)	Phase Diff (Pr.)
45	8.93	9.0	90	97
50	6.92	6.45	90	97
55	7.62	6.99	90	98
60	8.314	8.05	90	97
100	13.85	12.26	90	107

 

9.     Observe the output voltage and phase difference at different frequencies and amplitudes.

 

 

10.   Observe the output waveform with different types of input waveforms selected in the function generator. Set the frequency and the amplitude to check the impulse wave at output when square wave has been given as input from the function generator.

 

 

 

 

 

 

 

 

 

 

 

The differentiator circuit design output waveforms have been studied.