Basic Concepts of Electricity & Electromagnetism

Basic Concepts of Electricity

• Electricity is a set of physical phenomena related to the presence and flow of electric charges.
• Electricity manifests in various phenomena like lightning, static electricity, electromagnetic induction, and electric current flow.
• Electrification involves the loss or gain of electrons.
• Electrons need mobility to produce electricity.
• Metals allow the movement of electric charges and are called electrical conductors.
• Materials like glass and plastic impede the movement of electric charges and are called electrical insulators.

Theory of Electromagnetism

• Magnetism and electricity are closely related.
• Electromagnetism is a natural or artificial phenomenon that can produce much electricity economically.
• James Clerk Maxwell explained the relationship between electricity and magnetism around 1870.
• Electromagnetism has industrial applications in electric generators, dynamos or alternators, transformers, relays, and motors

Fundamentals of Electromagnetism

• Electromagnetism occurs when an electric current passes through a coil of wire wrapped around a support, creating a magnetic field similar to a natural magnet.
• More intense magnetic fields arise from a higher number of coil turns and increased current intensity

Applications of Electromagnetism

• Alternator, dynamo, and magnetic wheel functionality is based on induced current in a winding exposed to a changing magnetic field.

Transformers

• Transformers rely on self-induction and mutual induction.
• Transformers consist of primary and secondary coils wound around a ferromagnetic core.
• The induced voltage in the secondary coil depends on the ratio of turns between the primary and secondary coils, as well as the intensity of current circulating through the primary coil at interruption.
• Self-induction limits coil charging time, especially when saturation time is limited, as seen in high-speed ignition transformers.
• In a transformer, with an input of 120 Volts, a magnetic field is generated that induces current through the core material with an output of 3-12 Volts

Electron in Matter

• Electricity originates with the movement of electrons, which are a part of the atom.
• An atom is the smallest portion of matter with a nucleus containing protons with positive electrical charges and neutrons with no charge.
• Atoms can have many electrons in orbits around the nucleus; electrons can be removed from the outer orbits, creating a positive ion.
• The exit of an electron from its orbit leaves a "hole," which attracts an electron from a neighboring atom and thereby starts a cascade of freed electrons from other neighboring atoms filling successive holes, producing electron circulation.
• The force behind the movement of electrons in a conductor depends on the electron difference between the ends of the conductor.
• The natural trend is for electrons to circulate towards the end of a conductor with fewer electrons to reach equilibrium.
• An electron is very small in mass and has a unit of negative electrical charge.
• A proton has a much larger mass than an electron and has a unit of positive electrical charge.
• A neutron has no electrical charge and has the same mass as a proton.
• An atom has a nucleus and a cortex.
• Protons and neutrons gather in the nucleus at different numbers, depending on the element.
• Hydrogen has one proton, while sodium has eleven protons and twelve neutrons.
• The cortex consists of layers of electrons orbiting the nucleus in circles.

Electrical Machines

• Electrical machines can generate, harness, or transform electrical energy.
• A generator converts mechanical energy into electrical energy.
• A motor converts electrical energy into mechanical energy.
• A conductor with electric current inside a magnetic field moves in a direction perpendicular to the magnetic field.
• A coil with current circulating through it will have one side rising and the other going downward, leading to the coil's spin because one side of the coil receives the current while the other side expels it.

Electric Motors

• Electric motors are rotating electric machines.
• They transform electrical energy into mechanical energy with many benefits like economy, cleanliness, convenience, and safe operation.
• They now replace other energy sources in sectors like industry, transport, commerce, and home.
• Electric motors work by using the attraction/repulsion forces between a magnet and a wire coil by making an electric current circulate.
• Today’s electric motors contain many wire turns called windings in the rotor or rotating part and a large magnet called the stator on the stationary part of the motor surrounding the rotor.

The Dynamo and the Alternator

• Michael Faraday discovered that moving an electrical conductor inside a magnetic field generated a voltage and initiated an electric current when the circuit was closed with a receptor

The Dynamo

• To extract generated current in the coil, collectors that rotate with each end of the coil, and fixed brushes to get the current out are needed.
• Collectors are cut.

The Alternator

• The same brush changes polarity in each complete turn of the coil
• Similar but the collectors are not cut.

Electricity Production

• With the knowledge on electricity, the principles to generate electricity from magnetic fields and electrons in motion, it is possible to consider elements for commercial electricity production from biomass, geothermal, wind, thermal, and hydroelectric sources.

The Electric Current

• Two types of current exist: alternating current and direct current.

Direct Current

• Direct Current (DC) in which charges move in one direction.
  • Batteries produce this type of current.

Alternating Current

• Alternating Current (AC) is where charges flow in one direction before reversing.
• Polarity shifts cyclically in the circuit
• The number of cycles per second has a hertz (Hz) measurement.

Potential Difference

• The potential difference, or voltage between two points, is the energy required to move a positive charge from point A to point B.
• The unit to measure this is the volt, V.
• The voltage measures potential difference.
• The way that water requires pressure to circulate through a pipe, electrical tension or "force" is required to circulate electric current through a conductor.
• A voltmeter is an instrument that measures it. - It measures the voltage running in parallel in the circuit.

Current Intensity

• Current intensity is the amount of electric charge that passes through a conductor over time.
• Its unit is the ampere (A), where one ampere equals one coulomb of charge passing per second.
• An ammeter measures the intensity by being serially connected to the electrical circuit.

Electricity Production Based on Fossil Fuels

• Electricity generated from fossil fuels is a thermal plant.
• This includes other combustible elements like gas, coal, bunker fuel, nuclear energy, and wood, and this production follows the same basic principle.
• Electricity is produced through fossil fuels but sends large quanties of carbon dioxide into the atmosphere.
• High-voltage cables must traverse long distances, and the copper in the cables offers resistance to the current that gradually lowers the voltage output from collection points down to distribution centers.
• Overall, the same principle applies to other combustible systems to produce electric energy, though this production type is highly costly and polluting because of the large release of carbon dioxide to the environment.
• Global energy demands sustained at 14% from a rising population. - Factors are due to industrial development and improving life conditions particularly in developing nations that require higher energy consumption from fossil fuels, fission-based nuclear energy, and renewable energies

Computer Basics

Functional Model of a Computational System

• A computing system comprises interconnected elements to enable operations
• A computing system's components are the:
  • Central Processing Unit (CPU), the system's processing center.
  • Memory, divided into primary RAM and secondary storage.
  • Input/Output (I/O) Devices, enabling user and external system communication.
  • Buses, facilitating data transfer among system components.
  • Operating System, managing hardware and software resources.
• Modern society applies information and communication technologies, requiring individuals to actively engage rather than passively observe.

Computing Skills

• The ability to be competent in operating today’s technologies.

Computer

• Computing systems vary in form, size, capacity, and complexity.
• They all contain a common component - the computer.
• Understanding a computer's fundamentals is the beginning of gaining computer literacy.

Hardware, CPU and USB

• Hardware is any physical device that is part of a computer, camera, or other device.
  • Examples include computers, printers, scanners, digital cameras, barcode readers, and communication equipment.
• Computers integrate ports like the USB, which has become the standard input/output for data due to its high transfer speed and low cost.
• CPUs transform data into information.
• CPU manufacturers include the Intel and AMD brands - Hallmark CPU characteristics are brand, model, version, and speed

Software

• Software is a set of instructions with a logical sequence.
• Hardware cannot function or interact with the user without the software.

System Software

• System software manages operating system hardware functionality and allows equipment functioning.
• System software divides into operating systems and utilities and includes the following:
  • MS Windows, Linux, Unix, Mac OS, Symbian, iPhone OS, Android, BlackBerry, and Windows Phone.
• Utility support the operating system and include:
  • Hard drive partition software, install/uninstall software assistants, and archiving compressors/decompressors.
• Operating systems include:
  • Windows, Mac OS, Unix, Solaris, FreeBSD, OpenBSD, Chrome OS, and several Linux distributions.
• Mobile devices operating systems:
  • Android, iOS, BlackBerry OS, Windows 10 Mobile, and Tizen.
• Smart TV operating systems:
  • WebOS , Firefox OS, Tizen and Android TV.
• Smartwatch operating systems:
  • Android, WatchOS, Android Wear, WearOS 9, and OpenWatch

Operating System Function

• Operating systems consist of two modes: user and Kernel. - Kernel is the OS fundamental software operated in supervisor mode. - Enables OS complete access, enabling the execution of any CPU action - Linux and Windows OS have approximately 5 million code links - User programs like interface software have 10-20 times the amount o code
• User programs use graphical interfaces, libraries, graphic software with 10–20 times the amount of kernel code.

Application Software

• Application software carry out user tasks
• Application software is general in purpose for communication or programming.

Interface

• An interface connects and communicates with multiple systems, programs, devices, or components.
• A Graphical User Interface (GUI):
  • GUI environments use graphic objects and images to represent information and interaction.
• A Command Line Interface (CLI):
  • A CLI is a text-based interface to react to prompts.

Data V. Information

• Data refers to facts, events, or inputs that lack specific significance in themselves.
• Information describes or identifies an object or event and is processed as a set of data.

Basic Computer Operations

• Basic computer functions include input, processing, and output.
• Input occurs in the input unit, where user information is recorded.
• Memory stores all data in cells with direct interaction from a control unit.
• The central processor unit’s micro processor, arithmetic-logic unit ALU, works under the control unit CU, organizes data flow, gives commands and requests data, carries out logic, performs arithmetic calculations, then returns it to the CU and finally the memory
• Controllers close circuits by receiving data, ensuring user access to outputs.

Computer Components

• Computers have four basic functions: receiving, providing, processing, and storing data, through known hardware components like the:
  • Input, output, or memory devices.
  • The presentation style as vertical, horizontal, or PC.

Case / Cabinet

• Cases contain CPU devices that supply an adequate voltage.

Motherboard

• A motherboard is inside the CPU with electronic circuits to communicate between the CPU and ROM - With ports and additional controllers to video, voice and additional devices

Memory

• Memory stores data and program interactions with the CPU.
• Primary ROM read-only or RAM random access.
• Secondary permanent stores

Storage

• Memory, optical drivers - Can vary across computer systems
• Store in:
  • Magnetic as Terabytes large data
  • Optical on CD ROM and writable drives
  • State Solid SSD using solid state chips

Temporal Memory

• RAM is for temporary storage of the executing data and programs.
• Cache temporarily stores frequent process data for quicker processor access.
• Flash memory uses solid-state tech in USB and SSD devices. - Erasable memory enables data clearing

Permanent Storage

• HDD magnetic disks use spinning platters and a read/write head.
• Magneto-optical devices use magnetic and laser tech storage.
• SSD storage devices use solid-state with no mechanical parts.

Input Devices

• Input devices enable the user to enter data or instructions into the computer.
• The keyboard has alphanumeric characters that standardizes the QWERTY system.
• A mouse, also known as a computer pointing apparatus, enables the graphic selections on screens.

Output Devices

• Output Devices show the user how data changes.
• This includes monitors to show processed, or transformed outputs
• Or the form of paper copies from the printer.

Communication Device

• The computers are considered components of a much larger communication system and must be connected via modem, Wi-Fi, router, or network.
• Red connections link all sorts of hardware cards with shared components, cables, software, or operating systems.
• These communication device examples include LAN or WAN for an array of uses spanning varying distances.

Personal Computer Classifications

• Desktop: Built for home use.
• Laptops or Portables: Compact with rechargeable batteries for travel use.
• Notebooks and Ultrabooks: Lightweight laptops.
• Tablets: Touch optimized mobile devices.
• Mini PCs and NUCs: Small, low energy computers.

Network Classifications

• LANs are private connections that span short distances inside buildings using private cables.
• WANs are connected to vast geographic areas that linked separate structures in the community with access to high telecommunications.

Users

• Single systems have only one user, or mono users.
• Multiuser systems have shared access such as Servers