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Showing posts from September, 2008

How Camcorders Work

Introduction In most of the world, camcorders, or video camera-recorders, have been a familiar sight for nearly 20 years. People take them everywhere: to school plays, sports events, family reunions and even births! When you go to a popular tourist spot, you are surrounded by them. Camcorders have really taken hold in the United States, Japan and many other countries around the world because they are an extremely useful piece of technology that you can own for under $300 (or more than $100,000). How can such a small device do so much? Particularly for anyone born before the 1980s, it's simply amazing that quality video cameras are now readily available as consumer items, and that they're so easy to use. Camcorders have been a familiar sight for nearly 20 years. The Basics A typical analog camcorder contains two basic parts: * A camera section, consisting of a CCD, lens and motors to handle the zoom, focus and aperture * A VCR section, in which a

How Hard Disks Work

Introduction Nearly every desktop computer and server in use today contains one or more hard-disk drives. Every mainframe and supercomputer is normally connected to hundreds of them. You can even find VCR-type devices and camcorders that use hard disks instead of tape. These billions of hard disks do one thing well -- they store changing digital information in a relatively permanent form. They give computers the ability to remember things when the power goes out. In this article, we'll take apart a hard disk so that you can see what's inside, and also discuss how they organize the gigabytes of information they hold in files! Hard disks store digital information in a relatively permanent form. Hard Disk Basics Hard disks were invented in the 1950s. They started as large disks up to 20 inches in diameter holding just a few megabytes. They were originally called "fixed disks" or "Winchesters" (a code name used for a popular IBM product). They later became known

How Bluetooth Works

Introduction When you use computers, entertainment systems or telephones, the various pieces and parts of the systems make up a community of electronic devices. These devices communicate with each other using a variety of wires, cables, radio signals and infrared light beams, and an even greater variety of connectors, plugs and protocols. There are lots of different ways that electronic devices can connect to one another. For example: * ­C­­omponent cables * Electrical wires * Ethernet cables * ­WiFi * Infrared signals The art of connecting things is becoming more and more complex every day. In this article, we will look at a method of connecting devices, called Bluetooth, that can streamline the process. A Bluetooth connection is wireless and automatic, and it has a number of interesting features that can simplify our daily lives. ­The Problem When any two devices need to talk to each other, they have to agree on a number of points before the conversation can begin

How GPS Receivers Work

Introduction Our ancestors had to go to pretty extreme measures to keep from getting lost. They erected monumental landmarks, laboriously drafted detailed maps and learned to read the stars in the night sky. Things are much, much easier today. For less than $100, you can get a pocket-sized gadget that will tell you exactly where you are on Earth at any moment. As long as you have a GPS receiver and a clear view of the sky, you'll never be lost again. In this article, we'll find out how these handy guides pull off this amazing trick. As we'll see, the Global Positioning System is vast, expensive and involves a lot of technical ingenuity, but the fundamental concepts at work are quite simple and intuitive. When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning System (GPS) is actually a constellation of 27 Earth-orbiting satellites (24 in operation and three extras in case one fails). The U.S. military developed and imple

How WiMAX Works

Introduction Think about how you access the Internet today. There are basically three different options: * Broadband access - In your home, you have either a DSL or cable modem. At the office, your company may be using a T1 or a T3 line. * WiFi access - In your home, you may have set up a WiFi router that lets you surf the Web while you lounge with your laptop. On the road, you can find WiFi hot spots in restaurants, hotels, coffee shops and libraries. * Dial-up access - If you are still using dial-up, chances are that either broadband access is not available, or you think that broadband access is too expensive. The main problems with broadband access are that it is pretty expensive and it doesn't reach all areas. The main problem with WiFi access is that hot spots are very small, so coverage is sparse. What if there were a new technology that solved all of these problems? This new technology would provide: * The high speed of broadband service * Wireless rather

How WiFi Works

Introduction If you've been in an airport, coffee shop, library or hotel recently, chances are you've been right in the middle of a wireless network. Many people also use wireless networking, also called WiFi or 802.11 networking, to connect their computers at home, and some cities are trying to use the technology to provide free or low-cost Internet access to residents. In the near future, wireless networking may become so widespread that you can access the Internet just about anywhere at any time, without using wires. wireless router can allow multiple devices to connect to the Internet. One WiFi has a lot of advantages. Wireless networks are easy to set up and inexpensive. They're also unobtrusive -- unless you're on the lookout for a place to use your laptop, you may not even notice when you're in a hotspot. What Is WiFi? A wireless network uses radio waves, just like cell phones, televisions and radios do. In fact, communication across a wireless ne

How WAP Works

Introduction You and millions of other people around the world use the Internet every day -- to communicate with others, follow the stock market, keep up with the news, check the weather, make travel plans, conduct business, shop, entertain yourself and learn. Staying connected has become so important that it's hard to get away from your computer and your Internet connection because you might miss an e-mail message, an update on your stock or some news you need to know. With your business or your personal life growing more dependent on electronic communication over the Internet, you might be ready to take the next step and get a device that allows you to access the Internet on the go. Getty Images Wireless Internet can be built into your cell phone or received through a wireless card. That's where wireless Internet comes in. You've probably seen news or advertising about cell phones and PDAs that let you receive and send e-mail. This seems a logical next step, but there are

How Data Integration Works

Introduction For the average man, information technology (IT) is a mysterious universe filled with indecipherable programming languages and expensive hardware. Eavesdropping on IT technicians is almost like overhearing a conversation spoken in a foreign language. But despite this seemingly impenetrable language barrier, it can be critically important for decision-makers in businesses and organizations to understand the world of IT. One of the most important IT concepts is data integration. On the surface, data integration sounds like a simple idea. Because many organizations store information on multiple databases, they need a way to retrieve data from different sources and assemble it in a unified way. For example, let's imagine that an electronics company is preparing to roll out a new mobile device. The marketing department might want to retrieve customer information from a sales department database and compare it to information from the product department to create a targeted s