Essays on Low-Pass Filter

Signal filtering is one of the most fundamental practices in signal processing. The filters are widely incorporated in the signal processing circuits due to their indomitable role in data acquisition and also to get rid of all the unnecessary signals and frequencies which interfere with the quality of the main signal. These unwanted signals are commonly referred to as noises. Once the signal has been filtered, they are then processed as either analog or digital depending on the signals application. Some signals are however weak and thus require an amplification circuit so that the filtering circuits can be consistent. ...

PURPOSE

Design an active second order Low-pass filter and characterize its frequency response.EQUIPMENT AND COMPONENTS Oscilloscope Power Supply Function Generator UA741 or LM741 OP AMP 4.7 nF Capacitors

Resistors

PRELAB 1. The RC circuit is shown in the following figure. Node Voltage Analysis is done in order to generate a transfer function Tvs=V2sV1s. In the circuit, voltage at node A is also the input voltage (V1=VA), and voltage at node D is also the output voltage (V2=VD).

KCL at node B:

V1-VBR1=VB-V21/sC1+VB-VCR2 (1)

KCL at node C:

VB-VCR2=VC1/sC2 (2) V2=uVC→VC=V2u (3)

Simplifying (2):

VB=VC1+sR2C2 (4)

Then, substituting (3) to (4):

VB=V2u1+sR2C2 (5)

Substituting (3) and (5) to (1):

V1-V2u1+sR2C2R1=V2u1+sR2C2-V21sC1+V2u1+sR2C2-V2uR2 V1-V2u1+sR2C2R1=V2u1-u+sR2C21sC1+V2usR2C2R2 V1-V2u1+ ...

Introduction

Numerous electrical applications require an inverter, which converts Direct Current (DC) to Alternating Current (AC) power. Some of these applications require the stepping down of voltage levels when realizing this conversion, which signifies that the input DC power is greater than the AC power. Conversely, certain applications require the opposite: to step up voltage when performing the power conversion, which means that the input DC power is lower than the AC power. These requirements can be met through the use of Voltage Source Inverters and Current Source Inverters, respectively. However, some particular applications require to step down voltage for ...

Objective:

This experiment is about the implementation and testing of low-pass, high-pass, and band-pass filters. The frequency response of each filter is analyzed using Bode plots. The properties of passive devices will be used to explain the response.

Equipment List:

EQUIPMENT Oscilloscope 2 Function Generators

COMPONENTS

1µF Capacitors 1 kΩ Resistors

Relevant Theory/Background Information:

A low-pass filter is a filter that allows frequencies below a cut-off frequency while filtering out frequencies above this cut-off frequency. For a simple series RC circuit, a low-pass filter can be created by connecting the input signal to the resistor and taking the output from the capacitor. The cut-off frequency ...

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Abstract 3

Introduction 4 Problem 1 4 Problem 2 6 Problem 3 7 Problem 4 9 Problem 5 12 Discussion 13 Conclusion 14

References 15

Appendix 17 Abstract Noisy audio signals are relatively common and unavoidable. An important task of digital signal processing is to tackle this problem, so as to produce an almost, if not noiseless audio signal. One way of doing this is to use Finite Impulse Response (FIR) filters. Here we present our findings on different FIR filters, and their effects on an audio signal provided in ...

(QAM) Laboratory Report

For (XXX)

Objective: Components required: A carrier source, data source, phase shifter, multiplier, symbol mapping, noise channel, PCB board, phase scope and oscilloscope. Theory: There are two types of modulation technique namely analog and digital. QAM is a technique that uses both analog and digital modulation technique. It is the abbreviation used for Quadrature amplitude modulation. In analog modulation scheme it passes the two message signals by varying the amplitude of the two carrier waves using amplitude modulation method. In the case of digital modulation technique two digital bit streams are transferred in which ...

Introduction

Signals that are periodic can be represented in time and frequency. In any analysis there are major signals which are used; these signals include sine, triangle and square. Additional signals can be derived from the three main signals. There is an important component in signal technology, the low pass filter. This is an electronic gadget that used in the filtering process of the signals. The filtering process is undertaken by allowing all the frequency components that come below the cut-off frequency to go through the circuit while all other frequencies that are above cut-off frequency will be bypassed. Noise ...

Introduction

This report is about the design of a two-way crossover laud speakers. The major task is the building of the circuit diagram. In the design, I have ensured that the 12dB crossover follows the Linkwitz-Riley alignment. This is achieved through the use of a sub-Bessel filter whose Q is 0.5 instead of the common Butterworth alignment resulting from a Q of 0.707. At the crossover frequency, the Butterworth crossovers have a 3dB peak. This is the main problem of such crossovers. This problem occurs when the outputs are acoustically or electrically summed. With a filter whose Q is 0.5, the signal is ...