INSTRUMENTATION & CONTROL

To design Differentiator using operational amplifier and verify its functionality.



Operational amplifier 741 IC
Fixed DC power supply (14 volts)
Resistor ( 10Ω , ±1% tolerance carbon type )
Capacitor ( 0.1µF )
Resistor ( 330 Ω, 10 KΩ )
Hook up wires
Bread board
Fixed DC power supply (14 volts
Function generator
CRO



DIFFERENTIATOR
The differentiator or differentiation amplifier, its name implies that this perform the mathematical operation differentiation in this circuit the output waveform is derivative of the input of the input waveform. The differentiator may be constructed from a basic inverting amplifier. If an input resistor R1 is replaced by a capacitor.
The expression for the output voltage can be obtained from kirchoff’s current equation at node V2,

..........................................................i = IB+iF
as IB is negligible..............................èi = iF

.................................C1 d/dt(Vin-V2) = (V1-V0)/RF ………………….(1)
But V1 = V2 = 0 because of gain A is very large.

................................C1 d/dtVin = -V/Rf ……………………(2)

................................èVo = -RfC1d/dtVin ……………………(3)
The above equation show that the output voltage Vo is equal to RfC1 times the negative instantaneous rate of change of input voltage Vin with time it performs reverse operation of integration.
The input signal will be differentiated properly time period T of the input signal is less than or equal to the RC example wave shaping circuit to defect high frequency components in an input signal
...........................................RC ≥ T



1.Connect the circuit as shown in figure 1 for differentiator circuit
2.Here connect the capacitor as an input terminal series in input resistor R1
3.Apply input signal from the function generator to the CRO and get output
4.Calculate time period from the function generator to the CRO which should be less than RC.