Submitted by: Submitted by mangelawlee
Views: 10
Words: 1489
Pages: 6
Category: Science and Technology
Date Submitted: 03/30/2016 02:05 AM
Leung Ryan Kar Chun
10064951D
ENG 238
Lab: Operational Amplifier
Lab Report
Objectives
The purpose of the lab is to study some of the advanced Operational amplifier configurations commonly found in practical applications. This is divided into two sections. In section I, the circuits studied will include the integrator, the differentiator, the summing amplifier, and the differential equation solver. In section II, the voltage-to-current converter will be studied.
Apparatus Used
1. Experiment board
2. Resistors: different values (216Ω, 989Ω, 996Ω, 10kΩ, 10.04kΩ, 20.16kΩ, 20.18kΩ)
3. Capacitors: different values (0.22µF, 32.6nF)
4. Three 741 Operational Amplifiers
5. NI Elvis prototype station and relevant Soft Panel Instruments
Introduction
This laboratory deals with several amplifier circuits. Each of the circuits in the lab requires some thinking to understand how the circuit works and its practical limitations.
Integrator: The circuit in Fig. 1 is the lossless inverting integrator. As the name suggests, the circuit generates an output signal that corresponds to the integral of the input signal over time. The circuit can be analyzed using the standard Op-amp analysis techniques.
Fig. 1 Inverting integrator circuit
In the frequency domain, the output voltage is described as:
It can be seen that the output is directly proportional to the integral (1/s term) of the input signal and a steadily changing output voltage is produced for a constant amplitude sinusoidal input voltage. Notice that the DC gain (s = 0) at the output is theoretically infinite; hence any small DC signal at the input will saturate the Op-amp output over time. In a real integrator circuit, a large resistor in parallel with the capacitor is required to prevent the capacitor from storing charge due to offset currents and voltages at the input. This configuration is known as “lossy” integrator or a first order low-pass circuit, which is shown in Fig. 2....