INDUSTRIAL LIGHTNING SYSTEM

INDUSTRIAL LIGHTNING SYSTEM

Lighting is an essential service in all the industries. The power consumption by the industrial lighting varies between 2 to 10% of the total power depending on the type of industry. Innovation and continuous improvement in the field of lighting, has given rise to tremendous energy saving opportunities in this area. Lighting is provided in industries, commercial buildings, indoor and outdoor for providing comfortable working environment. The primary objective is to provide the required lighting effect for the lowest installed load i.e highest lighting at lowest power consumption.

Lighting Principles and Terminology

Illumination
The distribution of light on a horizontal surface. The purpose of all lighting is to produce illumination.

Circuit Watts
It is the total power drawn by lamps and ballasts in a lighting circuit under assessment.

Lumen
A measurement of light emitted by a lamp. As reference, a 100-watt incandescent lamp emits about 1750 lumens.

Footcandle
A measurement of the intensity of illumination. A footcandle is the illumination produced by one lumen distributed over a 1-square-foot area. For most home and office work, 30–50 footcandles of illumination is sufficient. For detailed work, 200 footcandles of illumination or more allows more accuracy and less eyestrain. For simply finding one's way around at night, 5–20 footcandles may be sufficient.

Efficacy
The ratio of light produced to energy consumed. It's measured as the number of lumens produced divided by the rate of electricity consumption (lumens per watt).

Color temperature
It is color of the light source. By convention, yellow-red colors (like the flames of a fire) are considered warm, and blue-green colors (like light from an overcast sky) are considered cool. Color temperature is measured in Kelvin (K) temperature.

Glare
The excessive brightness from a direct light source that makes it difficult to see what one wishes to see. A bright object in front of a dark background usually will cause glare. Bright lights reflecting off a television or computer screen or even a printed page produces glare. Intense light sources—such as bright incandescent lamps—are likely to produce more direct glare than large fluorescent lamps. However, glare is primarily the result of relative placement of light sources and the objects being viewed.

Dimming:-
A procedure of varying the luminous flux from lamps in a lighting installation, by way of an electrical or electronic component.

Discharge Lamp
Lamp in which the light is produced, directly or indirectly, by an electric discharge through a gas, a metal vapour, or a mixture of several gases and vapours.

Light:-
Electromagnetic radiation with a wavelength of between 380-720nm. Ultraviolet light has a wavelength of less than 380nm whilst infrared light is greater at 720nm. i.e the cooler and warmer end of the lighting spectrum.

Lux:-
The unit of illuminance, equal to one lumen per square metre (lm/m2)

High-pressure mercury (vapour) lamp:-
Mercury vapour lamp, with or without a coating of phosphor, in which during operation the partial pressure of the vapor is of the order of 105 Pa - for example: HPL and HPL-N lamps.

High-pressure sodium (vapour) lamp:-
Sodium vapour lamp in which the partial pressure of the vapour during operation is of the order of 104 Pa - for example, SON and SON-T lamps.

Incandescent lamp:-
Lamp in which an electric current is passed through a filament thus creating heat. The light is the glow produced.

Low-pressure mercury (vapor) lamp:-
Mercury vapor lamp, with or without a coating of phosphor, in which during operation the partial pressure of the vapor does not exceed 100 Pa - for example a 'TL' lamp.

Low-pressure sodium (vapor) lamp:-
Sodium vapor lamp in which the partial pressure of the vapor during operation does not exceed 5 Pa - for example a SOX lamp.

Metal halide lamp:-
Discharge lamp in which the major portion of the light is produced by the radiation from a mixture of a metallic vapour (for example, mercury) and the products of the dissociation of halides (for example, halides of thallium, indium or sodium) - for example: HCI-T/HQI-TS lamps.

Power Factor Correction (pfc):-
Electricity supply require that the companies require that the power factor at which the supply is used shall be maintained at not less than 0.9 lagging, on average between one meter reading and the next. Low power factors increase the KVa demand from the supply, reduces the useful load that can be safely handled by the cables and distribution equipment, and in some cases can attract additional tariff penalties. Lamp circuits which incorporate a choke, leakage reactance transformer, or an electronic ballast can have low power factors, often between 0.3 and 0.6. Low power factor from these circuits can be corrected by the addition of a compensation capacitor. These can be placed at the central point of the supply, locally for each group of luminaries , or integral within each luminaire.

Starter:-
Device for starting a discharge lamp (in particular a fluorescent lamp) that provides for the necessary preheating of the electrodes and/or causes a voltage surge in combination with the series ballast.

Types of Lighting
You'll find that you have several options to consider when selecting what type of lighting you should use
Types of lighting include:
1) Fluorescent lighting
2) High-intensity discharge lighting
3) Incandescent lighting
4) Low-pressure sodium lighting
5) Outdoor solar lighting

Lamp is equipment, which produces light. The most commonly used lamps are described briefly as follows:

INCANDESCENT LIGHT BULBS
Incandescent light bulbs consist of a glass enclosure (the envelope, or bulb) which is filled with an inert gas to reduce evaporation of the filament. Inside the bulb is a filament of tungsten wire, through which an electric current is passed. The current heats the filament to an extremely high temperature (typically 2000 K to 3300 K depending on the filament type, shape, size, and amount of current passed through). The heated filament emits light that approximates a continuous spectrum. The useful part of the emitted energy is visible light, but most energy is given off in the near-infrared wavelengths.

(Incandescence : The state of glowing from intense heat, as when a metal becomes white hot from an electric current flowing through it.)

Reflector lamps:
Reflector lamps are basically incandescent, provided with a high quality internal mirror, which follows exactly the parabolic shape of the lamp. The reflector is resistant to corrosion, thus making the lamp maintenance free and output efficient.

Gas discharge lamps:
The light from a gas discharge lamp is produced by the excitation of gas contained in either a tubular or elliptical outer bulb.
The most commonly used discharge lamps are as follows:
• Fluorescent tube lamps (FTL)
• Compact Fluorescent Lamps (CFL)
• Mercury Vapour Lamps
• Sodium Vapour Lamps
• Metal Halide Lamps

HALOGEN BULBS
Halogen light bulbs produce light in a similar method to a regular incandescent bulb. A halogen bulb has a filament made of Tungsten, which glows when electricity is applied, same as a regular incandescent bulb. What makes a halogen bulb different is that it is filled with halogen gas instead of argon gas like a regular bulb is. The halogen gas removes the carbon deposits on the inside of the bulb, caused by the burning of the tungsten filament, and re deposits it back on to the filament, resulting in a light bulb which can be burned at a higher temperature therefore creating, both a whiter as well as a brighter light per watt than a regular bulb. The average rated life of halogen bulbs are typically between 2,000 and 4,000 hours.

Types of Fluorescent Lamps
Two general types of fluorescent lamps include these:
Compact fluorescent lamps (CFLs)
Fluorescent tube and circline lamps

FLOURESCENT TUBE LIGHT
A fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapor. The excited mercury atoms produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. Compared with incandescent lamps, fluorescent lamps use less power for the same amount of light, generally last longer, but are bulkier, more complex, and more expensive than a comparable incandescent lamp. Fluorescent lamps - namely CFL's - are significantly more expensive than incandescent, but they are about 3 to 4 times as efficient as incandescent and last 10 times longer or more

COMPACT FLOURESCENT LIGHTS/ENERGY SAVER
A compact fluorescent lamp (CFL), also known as a compact fluorescent light bulb (or less commonly as a compact fluorescent tube [CFT]), is a type of fluorescent lamp. Many CFLs are designed to replace an incandescent lamp and can fit in the existing light fixtures formerly used for incandescents. Compared to general service incandescent lamps giving the same amount of visible light, CFLs use less power and have a longer rated life, but generally have a higher purchase price. Compact fluorescent lamps (CFLs) combine the energy efficiency of fluorescent lighting with the convenience and popularity of incandescent fixtures
CFLs can replace incandescents that are roughly 3–4 times their wattage, saving up to 75% of the initial lighting energy. Although CFLs cost 3–10 times more than comparable incandescent bulbs, they last 6–15 times as long (6,000–15,000 hours).

Low-Pressure Sodium Lighting
Low-pressure sodium lamps provide the most energy-efficient outdoor lighting compared to high-intensity discharge lighting, but they have very poor color rendition. Typical applications include highway and security lighting, where color isn't important.
Low-pressure sodium lamps work somewhat like fluorescent lamps. Like high-intensity discharge lighting, low-pressure sodium lamps require up to ten minutes to start and have to cool before they can restart. Therefore, they are most suitable for applications where they stay on for hours at a time. They are not suitable for use with motion detectors.

Mercury Vapor Lamps
Mercury vapor lamps—the oldest types of high-intensity discharge lighting—are used primarily for street lighting. Mercury vapor lamps provide about 50 lumens per watt. They cast a very cool blue/green white light. Most indoor mercury vapor lamps in arenas and gymnasiums have been replaced by metal halide lamps. Metal halide lamps have better color rendering> and a higher efficacy. However, like high-pressure sodium lamps, mercury vapor lamps have longer lifetimes (16,000–24,000 hours) than metal halide lamps.

Control Gear
The gears used in the lighting equipment are as follows:

Ballast:
A component that is used to stabilize the current flow through, or operation of, a circuit,stage or device. 2. An iron-core choke connected in series with one of the electrodes in a fluorescent or other gas-discharge lamp.

Ignitors:
These are used for starting high intensity Metal Halide and Sodium vapour lamps.

Recommended Illumination
Chemicals
Petroleum, Chemical and Petrochemical works Exterior walkways, platforms, stairs and ladders 30–50–100
Exterior pump and valve areas 50–100–150
Pump and compressor houses 100–150–200
Process plant with remote control 30–50–100
Process plant requiring occasional manual intervention 50–100–150
Permanently occupied work stations in process plant 150–200–300
Control rooms for process plant 200–300–500

Pharmaceuticals Manufacturer and Fine chemicals manufacturer
Pharmaceutical manufacturerGrinding, granulating, mixing, drying, tableting, s 300–500–750
terilising, washing, preparation of solutions, filling,
capping, wrapping, hardening

Fine chemical manufacturersExterior walkways, platforms, stairs and ladders 30–50–100
Process plant 50–100–150
Fine chemical finishing 300–500–750
Inspection 300–500–750
Soap manufacture
General area 200–300–500
Automatic processes 100–200–300
Control panels 200–300–500
Machines 200–300–500

Paint worksGeneral 200–300–500
Automatic processes 150–200–300
Control panels 200–300–500
Special batch mixing 500–750–1000
Colour matching 750–100–1500


USEFUL LIGHT CALCULATION FORMULAS FORMULAS
1) Demand for Power (kW) = System Input Wattage (W) ÷ 1,000
2) Energy Consumption (kWh) = System Input Wattage (kW) x Hours of Operation/Year
3) Hours of Operation/Year = Operating Hours/Day x Operating Days/Week x Operating Weeks/Year
4) Lighting System Efficacy (Lumens per Watt or LPW) = System Lumen Output ÷ Input Wattage
5) Unit Power Density (W/sq.ft.) = Total System Input Wattage (W) ÷ Total Area (Square Feet)
6) Watts (W) = Volts (V) x Current in Amperes (A) x Power Factor (PF)
7) Voltage (V) = Current in Amperes (A) x Impedance (Ohms) [Ohm's Law]


SELECTION CHART FOUND ON A TYPICAL INDUSTRIAL LUX METER
SELECTION ON A LUTRON LIGHT METER
1 for TUNGSTEN , SUN
2 for FLUORESCENT
3 for SODIUM
4 for MERCURY

Light Control
The simplest and the most widely used form of controlling a lighting installation is "On-Off" switch. The initial investment for this set up is extremely low, but the resulting operational costs may be high. This does not provide the flexibility to control the lighting, where it is not required.
Hence, a flexible lighting system has to be provided, which will offer switch-off or reduction in lighting level, when not needed. The following light control systems can be adopted at design stage:

• Grouping of lighting system, to provide greater flexibility in lighting control
Grouping of lighting system, which can be controlled manually or by timer control.

•Installation of microprocessor based controllersAnother modern method is usage of microprocessor / infrared controlled dimming or switching
circuits. The lighting control can be obtained by using logic units located in the ceiling, which
can take pre-programme commands and activate specified lighting circuits. Advanced lighting
control system uses movement detectors or lighting sensors, to feed signals to the controllers.

• Optimum usage of daylighting
Whenever the orientation of a building permits, day lighting can be used in combination with electric lighting. This should not introduce glare or a severe imbalance of brightness in visual environment. Usage of day lighting (in offices/air conditioned halls) will have to be very limited, because the air conditioning load will increase on account of the increased solar heat dissipation into the area. In many cases, a switching method, to enable reduction of electric light in the window zones during certain hours, has to be designed.

• Installation of "exclusive" transformer for lighting
In most of the industries, lighting load varies between 2 to 10%. Most of the problems faced by the lighting equipment and the "gears" is due to the "voltage" fluctuations. Hence, the lighting equipment has to be isolated from the power feeders. This provides a better voltage regulation for the lighting. This will reduce the voltage related problems, which in turn increases the efficiency of the lighting system.

• Installation of servo stabilizer for lighting feeder
Wherever, installation of exclusive transformer for lighting is not economically attractive, servo stabilizer can be installed for the lighting feeders. This will provide stabilized voltage for the lighting equipment. The performance of "gears" such as chokes, ballasts, will also improved due to the stabilized voltage. This set up also provides, the option to optimise the voltage level fed to the lighting feeder. In many plants, during the non-peaking hours, the voltage levels are on the higher side. During this period, voltage can be optimised, without any significant drop in the illumination level.

Lighting Occupancy Sensor Controls
Occupancy sensors detect activity within a certain area. They provide convenience by turning lights on automatically when someone enters a room. They reduce lighting energy use by turning lights off soon after the last occupant has left the room.
Occupancy sensors must be located where they will detect occupants or occupant activity in all parts of the room. There are two types of occupancy sensors: ultrasonic and infrared. Ultrasonic sensors detect sound, while infrared sensors detect heat and motion. In addition to controlling ambient lighting in a room, they are useful for task lighting applications, such as over kitchen counters. In such applications, task lights are turned on by the motion of a person washing dishes, for instance, and automatically turn off a few minutes after the person stops

Lighting Photosensor Controls
You can use photosensors to prevent outdoor lights from operating during daylight hours. This can help save energy because you don't have to remember to turn off your outdoor lights. Photosensors sense ambient light conditions, making them useful for all types of outdoor lighting. They offer little utility in controlling lights inside the home because lighting needs vary with occupant activity rather than ambient lighting levels.

Types of Solar Cells
The performance of a solar or photovoltaic (PV) cell is measured in terms of its efficiency at converting sunlight into electricity. There are a variety of solar cell materials available, which vary in conversion efficiency.
Semiconductor Materials
A solar cell consists of semiconductor materials. Silicon remains the most popular material for solar cells, including these types:
Monocrystalline or single crystal silicon
Multicrystalline silicon
Polycrystalline silicon
Amorphous silicon
The absorption coefficient of a material indicates how far light with a specific wavelength (or energy) can penetrate the material before being absorbed. A small absorption coefficient means that light is not readily absorbed by the material. Again, the absorption coefficient of a solar cell depends on two factors: the material making up the cell, and the wavelength or energy of the light being absorbed.

COMPUTER BASICS FOR EVERYONE

What is a Computer?

An electronic device for processing information and performing calculations; follows a program to perform sequences of mathematical and logical operations

Computer Parts

A computer has various parts, and each part performs a specific function.

Part Description

Input Devices

You use input devices to provide information to a computer, such as typing a letter or giving instructions to a computer to perform a task. Some examples of input devices are described as follows

Mouse:

A device that you use to interact with items displayed on the computer screen. A standard mouse has a left and a right button. You use the left button to select items and provide instructions by clicking an active area on the screen. You use the right button to display commonly used menu items on the screen.

Keyboard:

A set of keys that resembles a typewriter keyboard. You use the keyboard to type text, such as letters or numbers into the computer.

Microphone:

A device that you can use to talk to people in different parts of the world. You can record sound into the computer by using a microphone. You can also use a microphone to record your speech and let the computer convert it into text.

Scanner:

A device that is similar to a photocopy machine. You can use this device to transfer an exact copy of a photograph or document into a computer. A scanner reads the page and translates it into a digital format, which a computer can read. For example, you can scan photographs of your family using a scanner.

Webcam:

A device that is similar to a video camera. It allows you to capture and send the live pictures to the other user. For example, a webcam allows your friends and family to see you when communicating with them.

Output Devices

You use output devices to get feedback from a computer after it performs a task. Some examples of output devices are described as follows.

Monitor:

A device that is similar to a television. It is used to display information, such as text and graphics, on the computer.

Printer:

A device that you use to transfer text and images from a computer to a paper or to another medium, such as a transparency film. You can use a printer to create a paper copy of whatever you see on your monitor.

Speaker/Headphone

Devices that allow you to hear sounds. Speakers may either be external or built into the computer.

Central Processing Unit and Memory

The central processing unit (CPU) is a device that interprets and runs the commands that you give to the computer. It is the control unit of a computer. The CPU is also referred to as the processor.

Memory is where information is stored and retrieved by the CPU. There are two main types of memory.

Random Access Memory (RAM):

It is the main memory and allows you to temporarily store commands and data. The CPU reads data and commands from RAM to perform specific tasks. RAM is volatile, which means it is available only while the computer is turned on. The contents of RAM must be copied to a storage device if you want to save the data in the RAM.

Read Only Memory (ROM):

It is the memory that retains its contents even after the computer is turned off. ROM is nonvolatile, or permanent, memory that is commonly used to store commands, such as the commands that check whether everything is working properly or not.

Motherboard

The motherboard is the main circuit board inside the computer. It has tiny electronic circuits and other components on it. A motherboard connects input, output, and processing devices together and tells the CPU how to run. Other components on the motherboard include the video card, the sound card, and the circuits that allow the computer to communicate with devices like the printer. The motherboard is sometimes called a system board.

Expansion Cards

An expansion card is a circuit board that can be attached to the motherboard to add features such as video display and audio capability to your computer. An expansion card either improves the performance of your computer or enhances its features. Expansion cards are also called expansion boards. Some types of expansion cards are described below.

Video Card:

It is connected to the computer monitor and is used to display information on the

monitor.

Network Interface Card (NIC):

It allows the computer to be connected to other computers so that information can be exchanged between them.

Sound Card:

It converts audio signals from a microphone, audio tape, or some other source to digital signals, which can be stored as a computer audio file. Sound cards also convert computer audio files to electrical signals, which you can play through a speaker or a headphone. The microphone and the speakers or the headphones connect to the sound card.

Storage Devices

You use storage devices to store computer information. Storage devices come in many forms. Some examples are hard drive or disk, CDROM, floppy disk, and DVD‐ROM. Storage devices can be divided into two types, internal storage devices and external storage devices. Some common storage devices are described below

Hard Disk:

A magnetic disk that is usually the main storage device on most computers. It can be an external or an internal device.

Floppy Disk:

A portable storage device that allows you to store a small amount of data. A disadvantage of this disk is that it can be easily damaged by heat, dust, or magnetic fields.

CD‐ROM:

A portable storage medium that allows you to store 400 times more data than on a floppy disk. It is less prone to damage than a floppy disk.

DVD‐ROM:

A portable storage medium that is similar to a CD‐ROM; however, it can store larger amounts of data than a floppy disk or a CD‐ROM. A DVD‐ROM is commonly used to store movies and videos.

Ports and Connections

A port is a channel through which data is transferred between input/output devices and the processor. There are several types of ports that you can use to connect the computer to external devices and networks. Some types of ports below

Universal Serial Bus (USB) Port:

You use this to connect peripheral devices such as a mouse, a modem, a keyboard, or a printer to a computer.

FireWire:

You use this to connect devices such as a digital camera. It is faster than the USB.

Network Port:

You use this to connect a computer to other computers to exchange information between the computers.

Parallel Port and Serial Port:

You use these ports to connect printers and other devices to a personal computer. However, the USB is now the preferred method for connecting peripheral devices because it is faster and easier to use.

Display Adapter:

You connect a monitor to the display adapter on your computer. The display adapter generates the video signal received from the computer, and sends it to a monitor through a cable. The display adapter may be on the motherboard, or on an expansion card.

Power:

The motherboard and other components inside a computer use direct current (DC). A power supply takes the alternating current (AC) from the wall outlet and converts it into DC power.

STRESS

STRESS

Stress is the internal resistance of a material to the distorting effects of an external force or load.

Stress, s = f/a

When a metal is subjected to a load (force), it is distorted or deformed, no matter how strong the metal or light the load. If the load is small, the distortion will probably disappear when the load is removed. The intensity, or degree, of distortion is known as strain. If the distortion disappears and the metal returns to its original dimensions upon removal of the load, the strain is called elastic strain. If the distortion disappears and the metal remains distorted, the strain type is called plastic strain.

Stress is the internal resistance, or counterforce, of a material to the distorting effects of an external force or load. These counterforces tend to return the atoms to their normal positions. The total resistance developed is equal to the external load. This resistance is known as stress.

Although it is impossible to measure the intensity of this stress, the external load and the area to which it is applied can be measured. Stress (s) can be equated to the load per unit area or the force (f) applied per cross-sectional area (a) perpendicular to the force as shown

Stress, s = f/a

Where:

s = stress (psi or lbs of force per in.2)

F = applied force (lbs of force per in.2)

A = cross-sectional area (in.2)

Types of stress

Stresses occur in any material that is subject to a load or any applied force. There are many types of stresses, but they can all be generally classified in one of six categories

1) Residual stress

Residual stresses are due to the manufacturing processes that leave stresses in a material. Welding leaves residual stresses in the metals welded

2) Structural stress

Structural stresses are stresses produced in structural members because of the weights they support. The weights provide the loadings. These stresses are found in building foundations and frameworks, as well as in machinery parts.

3) Pressure stress

Pressure stresses are stresses induced in vessels containing pressurized materials. The loading is provided by the same force producing the pressure. In a reactor facility, the reactor vessel is a prime example of a pressure vessel.

4) Flow stress

Flow stresses occur when a mass of flowing fluid induces a dynamic pressure on a

conduit wall. The force of the fluid striking the wall acts as the load. This type of

Stress may be applied in an unsteady fashion when flow rates fluctuate. Water hammer is an example of a transient flow stress.

5) Thermal stress

Thermal stresses exist whenever temperature gradients are present in a material.

Different temperatures produce different expansions and subject materials to internal stress. This type of stress is particularly noticeable in mechanisms operating at high temperatures that are cooled by a cold fluid

6) Fatigue stress

Fatigue stresses are due to cyclic application of a stress. The stresses could be due to vibration or thermal cycling.

Types of applied stresses

These are known as tensile, compressive, and shear

As illustrated in figure, the plane of a tensile or compressive stress lies perpendicular to the axis of operation of the force from which it originates. The plane of a shear stress lies in the plane of the force system from which it originates.

a) Tensile stress

Tensile stress is that type of stress in which the two sections of material on either side of a stress plane tend to pull apart or elongate

b) Compressive stress

Compressive stress is the reverse of tensile stress. Adjacent parts of the material tend to press against each other through a typical stress plane

c) Shear stress

Shear stress exists when two parts of a material tend to slide across each other in any typical plane of shear upon application of force parallel to that plane

Assessment of mechanical properties is made by addressing the three basic stress types. Because tensile and compressive loads produce stresses that act across a plane, in a direction perpendicular (normal) to the plane, tensile and compressive stresses are called normal stresses.

Two types of stress can be present simultaneously in one plane, provided that one of the stresses is shear stress. Under certain conditions, different basic stress type combinations may be simultaneously present in the material. An example would be a reactor vessel during operation. The wall has tensile stress at various locations due to the temperature and pressure of the fluid acting on the wall. Compressive stress is applied from the outside at other locations on the wall due to outside pressure, temperature, and constriction of the supports associated with the vessel. In this situation, the tensile and compressive stresses are considered principal stresses. If present, shear stress will act at a 90° angle to the principal stress.

INTERNET: AN INTRODUCTION

INTERNET: AN INTRODUCTION
The Internet is the largest computer network in the world. It consists of millions of computers all over the planet, all connected to each another

World Wide Web
The World Wide Web is what you probably think of when you think of the Internet, although it’s really just a part of the Internet. The Web consists of millions of documents that are stored on hundreds of thousands of computers that are always connected to the Internet. These documents are called Web pages, and you can find Web pages on every subject imaginable—from your local newspaper to online catalogs to airline schedules, and much more.

Web Servers
Web pages are stored on Web servers. A Web server is a computer, not unlike your own computer, only bigger and faster. There are hundreds of thousands of Web servers located all over the world. Web servers are always connected to the Internet so that people can view their Web pages 24 hours a day.

What Can I do on the Internet?

Send and Receive E-mail
Exchanging electronic mail (or e-mail) is the most popular feature on the Internet. Just like regular paper mail, you can send and receive e-mail with people around the world, as long as they have access to a computer and the Internet. Unlike regular paper mail, e-mail is delivered to its destination almost instantly.

Browse the World Wide Web
The World Wide Web is what most people think of when they think of the Internet—although it’s really only a part of the Internet. The World Wide Web is an enormous collection of interconnected documents stored on Web servers all over the world. The World Wide Web has information on every subject imaginable.

Join online discussions with newsgroups
Newsgroups are discussion groups on the Internet that you can join to read and post messages to and from people with similar interests. There are thousands of newsgroups on topics such as computers, education, romance, hobbies, politics, religion, and more.

Chat with other online users
Chatting lets you communicate with people on the Internet instantly—no matter how far away they are! Most chats are text-based, meaning you have to type when you converse with people on the Internet. A growing number of chats have voice and even video capabilities—all without having to pay long distance changes.

Download software
You can download pictures, demo programs, patches and drivers for your computer, and many other types of files and save them to your computer.

Listen to music and watch videos
You can listen to sound on the Web, such as radio stations, or music by your favorite artists.

Requirements for using the internet
There are three things you’ll need to connect to the Internet:

1. An Internet Service Provider (ISP):
An Internet Service Provider is a lot like a phone company, except instead of letting you make telephone calls to other people, an Internet Service Provider lets your computer connect to the Internet. Just like your telephone company, Internet Service Providers charge for their services.

2. A Web Browser:
A Web browser is a program that lets your computer view and navigate the World Wide Web. Windows comes with a built-in Web browser—Internet Explorer.

3. A Phone Line and Modem or Other Connection:
A modem is your computer’s very own telephone that lets it talk to other computers on the Internet. There are slower dial-up modems that connect to the Internet using your phone and much faster cable modems and Digital Subscriber Lines (DSL) as well. DSL is technology that provides high-speed Internet access through standard phone lines. A cable modem connects to the Internet through the cable hookup in your house. Both of these connections are much faster than a dial-up modem and are connected to the Internet 24 hours a day, so you don’t tie up any phone lines.

Web addresses
Web addresses are everywhere—on television advertisements, in magazine and newspaper articles, and even on business cards. These www.something.coms you’ve seen and heard so much about are URLs (Uniform Resource Locator). Just like there is a house, office, or building behind a postal address, there is a Web page behind every Web address. Unlike postal addresses, however, through the magic of technology you can instantly arrive at a Web page by typing its Web address, or URL, into your Web browser

Searching
The Internet’s greatest strength is also its greatest weakness: with so much information— literally millions of Web pages—it can be extremely difficult to find what you’re looking for. Fortunately, there are many search engines that catalog the millions of Web pages on the Internet so that you can find Web pages on topics that interest you, such as Google, Yahoo! and Excite.

Downloading
Another common use of the Internet is to download files from a Web server and save them onto your local hard drive. Some of the most common types of files people download from the Internet include:

Images:
You can save any picture that you see on a Web page, print it, use it as your
Windows wallpaper, or anything else you can think of.

Programs:
Many software companies have demo versions of their programs available on the Internet that you can download and evaluate. In addition, thousands of shareware programs are available for you to download for free!

Patches, Fixes, and Drivers:
One of the great things about the Internet is finding fixes for your programs, and drivers for your hardware devices, such as a driver for a discontinued foreign printer.

Music:
MP3s are revolutionizing the music industry. MP3 files are sound files that you can listen to on your computer. They have digital CD quality sound, but use compression so that they are 11 times smaller than the CD equivalent and small enough to be easily downloadable from the Internet.

Viruses:
Just kidding—the last thing you want to download from the Internet is a computer virus! Since you won’t always know where a program or file you want to download comes from, you should make sure your computer has a virus protection program installed before you download anything from the Internet.

Understanding Information Security
Information security is the practice of protecting your computer from intruders. Here are some security precautions that help protect your sensitive information. Install anti-virus software; Update anti-virus software; Update software; Use firewalls; Be smart with e-mail

Understanding Windows Firewall
This security utility keeps your computer secure by restricting the information that comes into your Computer

Different Types of Connections
The first step in going online is establishing a connection between your computer and the Internet. To do this, you have to sign up with an Internet service provider (ISP), which, as the name implies, provides your home with a connection to the Internet. Depending on what’s available in your area, you can choose from two primary types of connections—dial-up or broadband. Dial-up is slower than broadband, but it’s also lower priced. That said, dial-up connections are going the way of the dodo bird; if you do a lot of web surfing, it’s probably worth a few extra dollars a month to get the faster broadband connection.

Traditional Dial-Up
A dial-up connection provides Internet service over normal phone lines. The fastest dial-up connections transmit data at 56.6Kbps (kilobits per second), which is okay for normal web surfing but isn’t fast enough for downloading music or videos.

Broadband DSL
DSL is a phone line-based technology that operates at broadband speeds. DSL service piggybacks onto your existing phone line, turning it into a high-speed digital connection. Not only is DSL faster than dial-up (384Kbps to 10Mbps, depending on your ISP), you also don’t have to surrender your normal phone line when you want to surf; DSL connections are “always on.”

Broadband Cable
Another popular type of broadband connection is available from your local cable company. Broadband cable Internet piggybacks on your normal cable television line, providing speeds in the 500Kbps to 30Mbps range, depending on the provider.

Broadband Satellite
If you can’t get DSL or cable Internet in your area, you have another option—connecting to the Internet via satellite. Any household or business with a clear line of sight to the southern sky can receive digital data signals from a geosynchronous satellite at 700Kbps

Connecting to a Public WiFi Hotspot
If you have a notebook PC, you also have the option to connect to the Internet when you’re out and about. Many coffeehouses, restaurants, libraries, and hotels offer wireless WiFi Internet service, either free or for an hourly or daily fee. Assuming that your notebook has a built-in WiFi adapter (and it probably does), connecting to a public WiFi hotspot is a snap. When you’re near a WiFi hotspot, your PC should automatically pick up the WiFi signal. Make sure that your WiFi adapter is turned on (some notebooks have a switch for this, either on the front or on the side of the unit), and then look for a wireless connection icon in Windows’ system tray or notification area. Click this icon (or select Start, Connect To), and Windows displays a list of available wireless networks near you. Select the network you want to connect to; then click the Connect button.