iPhone

The iPhone is an internet-connected multimedia smartphone designed and marketed by Apple Inc. with a flush multi-touch screen and a minimal hardware interface. The device does not have a physical keyboard, so a virtual keyboard is rendered on the touch screen instead. The iPhone functions as a camera phone (including text messaging and visual voicemail), a portable media player (equivalent to an iPod), and an Internet client (with email, web browsing, and local Wi-Fi connectivity). The first-generation phone hardware was quad-band GSM with EDGE; the second generation also adds UMTS with HSDPA.Apple announced the iPhone on January 9, 2007.[10] The announcement was preceded by rumors and speculation that circulated for several months.[11] The iPhone was initially introduced in the United States on June 29, 2007, and has since been introduced worldwide. It was named Time magazine's "Invention of the Year" in 2007.[12] On July 11, 2008, the iPhone 3G was released. It supports faster 3G data speeds and Assisted GPS.[9] On March 17, 2009, Apple announced the iPhone firmware version 3.0, due to be released in summer 2009.

Cyber-shotSony Cyber-shot DSC-H9

Cyber-shot is a line of digital cameras made by Sony. The Cyber-shot range is well known for its proprietary InfoLithium battery pack, the trademark Carl Zeiss lenses and overall design. Also, all Cyber-shot cameras accept Sony's proprietary Memory stick or Memory Stick PRO Duo flash memory. Some high-end models have also supported Compact Flash. All Cyber-shot models have a DSC prefix in their names, which is an acronym for "Digital Still Camera".Almost exactly 12 months after the launch of the Cyber-shot DSC-H2 and DSC-H5 Sony announced the replacement cameras; the DSC-H7 and the top-of-the-range model reviewed here; the DSC-H9. That Sony chose to increase the pixel count (to 8MP) and to include this year's 'must have' features (face detection and ludicrously high maximum ISO) can't have surprised many, but there are a few less predictable new features, and a few welcome changes. The former include Sony's unique 'NightShot' infra-red mode (seen on many camcorders as well as a few Cyber-shots over the years), a 15x zoom and HDTV (well, 1080i) output. The latter include an articulated (tilt-up) screen, improved focus system, faster performance and a new (in the box) remote control.

Sony DVD506E camcorder

With the addition of DVD+R DL (Dual-Layer) recording, the Sony DCR-DVD506E camcorder can now record for a maximum of 110 minutes, almost doubling the 60 minutes maximum record time of previous-generation DVD Handycam. The latest Sony DVD506E Handycam range doesn’t just store more on every DVD: it offers greater battery stamina than predecessor models, too. The new H-Series InfoLITHIUM battery dramatically boosts continuous recording STAMINA to 9 hours from a single charge.mage quality and new features aside, the latest DVD506 model is even easier and more convenient to use. The Sony DCR-DVD506E DVD Handycam now includes a Colour Viewfinder for framing and reviewing shots, while additional Record Start/Stop and zoom buttons are thoughtfully placed on the border of the camcorder’s flip-out LCD screen. The new-generation Home menu and Help function on the LCD touch screen assures intuitive operation.Sony manufactures audio, video, communications and information technology products for the global consumer and professional markets. With its music, pictures, game and online businesses, Sony is uniquely positioned to be one of the World´s Leading Consumer Brands. Sony recorded consolidated annual sales of EUR 54.96 b illion (yen 7,475 billion) for the fiscal year ended March 31, 2006 and it employs approximately 158,500 people worldwide.

Broadband Global Area Network

The Broadband Global Area Network or BGAN for short, is a global Satellite Internet Network with telephony using portable terminals. The terminals are normally used to connect a laptop computer to broadband Internet in remote locations, although as long as line-of-sight to the satellite exists, the terminal can be used anywhere. The value of BGAN terminals is that unlike other satellite Internet services which require bulky & heavy satellite dishes to connect, a BGAN terminal is smaller than a laptop and thus can be carried anywhere, and used globally. The network is provided by INMARSAT and uses three geostationary satellites with global service (except for the polar regions) ^[1].Downlink speeds of high-end BGAN terminals are up to 492kb/s and upload speeds slightly lower at 300-400kb/s. As with all satellite connections, latency is an issue. BGAN uses improved PEP software or other TCP packet accelerators or third party VPN's such as Skypipe to improve performance.

Dell Dimension 8200 (2.8GHz Pentium 4)

As befits a performance-orientated PC, the 2.8GHz Dimension 8200 uses Rambus memory – two of the motherboard’s four RIMM slots are filled with 256MB PC800 modules, giving a total of 512MB and a theoretical RAM capacity of 2GB. Co-ordinating the CPU, memory and peripheral subsystems is Intel’s 850E chipset, which supports the 533MHz frontside bus but cannot handle the latest Ultra-ATA/133 hard disks or USB 2.0 peripherals. Dell has got around the USB 2.0 problem in previous review systems by fitting a PCI card, but did not do so with our 2.8GHz machine. Digital video enthusiasts should note that FireWire is not available as standard on this PC, although there are two free PCI slots available for adding any missing functionality. Hard disk storage is provided by a fast 7,200rpm 120GB Western Digital drive, while optical media are taken care of by a Philips DVD+RW drive and a fast 48-speed CD-ROM drive. There are no spare external 5.25in.

iPod

iPod is a brand of portable media players designed and marketed by Apple Inc. and launched on October 23, 2001 (2001-10-23). The product line-up includes the hard drive-based iPod Classic, the touchscreen iPod Touch, the video-capable iPod Nano, and the compact iPod Shuffle. The iPhone can function as an iPod but is generally treated as a separate product. Former iPod models include the iPod Mini and the spin-off iPod Photo (since reintegrated into the main iPod Classic line). iPod Classic models store media on an internal hard drive, while all other models use flash memory to enable their smaller size (the discontinued Mini used a Microdrive miniature hard drive). As with many other digital music players, iPods, excluding the iPod Touch, can also serve as external data storage devices. Storage capacity varies by model.Apple's iTunes software can be used to transfer music to the devices from computers using certain versions of Apple Macintosh and Microsoft Windows operating systems.[2] For users who choose not to use Apple's software or whose computers cannot run iTunes software, several open source alternatives to iTunes are also available.[3] iTunes and its alternatives may also transfer photos, videos, games, contact information, e-mail settings, Web bookmarks, and calendars to iPod models supporting those features. As of September 2008[update], more than 173 million iPods had been sold worldwide, making it the best-selling digital audio player series in history

A Laptop

A laptop (also known as a notebook) is a personal computer designed for mobile use small enough to sit on one's lap.[1] A laptop includes most of the typical components of a typical desktop computer, including a display, a keyboard, a pointing device (a touchpad, also known as a trackpad, or a pointing stick) as well as a battery, into a single small and light unit. The rechargeable battery required is charged from an AC/DC adapter (ie, a wall wart) and typically stores enough energy to run the laptop for several hours.Laptops are usually shaped like a large notebook with thicknesses between 0.7–1.5 inches (18–38 mm) and dimensions ranging from 10x8 inches (27x22cm, 13" display) to 15x11 inches (39x28cm, 17" display) and up. Modern laptops weigh 3 to 12 pounds (1.4 to 5.4 kg); older laptops were usually heavier. Most laptops are designed in the flip form factor to protect the screen and the keyboard when closed. Modern 'tablet' laptops have a complex joint between the keyboard housing and the display, permitting the display panel to twist and then lay flat on the keyboard housing. They usually have a touchscreen display and some include handwriting recognition or graphics drawing capability.

Epson PowerLite 83+ Multimedia Projector

The Epson® PowerLite® 83+ offers an easy, affordable way to bring brilliant presentations to any classroom or office. Closed captioning functionality is included, so this lightweight, full-featured performer has all the tools you need to accommodate the hearing-impaired. And with 2200 lumens and Epson 3LCD technology, it delivers bright, vibrant images to virtually any audience.
This innovative performer makes everything easy. It also includes a built-in 10W speaker for truly amazing audio, without the added cost of additional speakers. RJ-45 port connectivity allows users to monitor and control the PowerLite 83+ over a network. Convenient lamp and air filter access, facilitates easy and affordable replacements. There’s even an energy-efficient lamp that delivers more lumens per watt, lasts up to 4000 hours¹ and saves in additional costs.
Discover the key to delivering remarkable presentations, while staying within budget. The PowerLite 83+ offers an A+ solution in one compact performer.

Parallel plate model

Dielectric is placed between two conducting plates, each of area A and with a separation of d

The simplest capacitor consists of two parallel conductive plates separated by a dielectric with permittivity ε. The model may also be used to make qualitative predictions for other device geometries. The plates are considered to extend uniformly over an area A and a charge density ±ρ = ±Q/A exists on their surface. Assuming that the width of the plates is much greater than their separation d, the electric field near the centre of the device will be uniform with the magnitude E = ρ/ε. The voltage is defined as the line integral of the electric field between the plates

Solving this for C = Q/V reveals that capacitance increases with area and decreases with separation

.

The capacitance is therefore greatest in devices made from materials with a high permittivity.

capacitor

A capacitor or condenser is a passive electronic component consisting of a pair of conductors separated by a dielectric. When a voltage potential difference exists between the conductors, an electric field is present in the dielectric. This field stores energy and produces a mechanical force between the plates. The effect is greatest between wide, flat, parallel, narrowly separated conductors.An ideal capacitor is characterized by a single constant value, capacitance, which is measured in farads. This is the ratio of the electric charge on each conductor to the potential difference between them. In practice, the dielectric between the plates passes a small amount of leakage current. The conductors and leads introduce an equivalent series resistance and the dielectric has an electric field strength limit resulting in a breakdown voltage.The properties of capacitors in a circuit may determine the resonant frequency and quality factor of a resonant circuit, power dissipation and operating frequency in a digital logic circuit, energy capacity in a high-power system, and many other important aspects.

Rectifier output smoothing

While half-wave and full-wave rectification suffice to deliver a form of DC output, neither produces constant-voltage DC. In order to produce steady DC from a rectified AC supply, a smoothing circuit, sometimes called a filter^[1], is required. In its simplest form this can be what is known as a reservoir capacitor, filter capacitor or smoothing capacitor, placed at the DC output of the rectifier. There will still remain an amount of AC ripple voltage where the voltage is not completely smoothed. RC-Filter Rectifier: This circuit was designed and simulated using Multisim 8 software.Sizing of the capacitor represents a tradeoff. For a given load, a larger capacitor will reduce ripple but will cost more and will create higher peak currents in the transformer secondary and in the supply feeding it. In extreme cases where many rectifiers are loaded onto a power distribution circuit, it may prove difficult for the power distribution authority to maintain a correctly shaped sinusoidal voltage curve.

Full-wave rectification

A full-wave rectifier converts the whole of the input waveform to one of constant polarity (positive or negative) at its output. Full-wave rectification converts both polarities of the input waveform to DC (direct current), and is more efficient. However, in a circuit with a non-center tapped transformer, four diodes are required instead of the one needed for half-wave rectification. (See semiconductors, diode). Four rectifiers arranged this way are called a diode bridge or bridge rectifier:

Gratz bridge rectifier: a full-wave rectifier using 4 diodes.For single-phase AC, if the transformer is center-tapped, then two diodes back-to-back (i.e. anodes-to-anode or cathode-to-cathode) can form a full-wave rectifier. Twice as many windings are required on the transformer secondary to obtain the same output voltage compared to the bridge rectifier above.

Selenium and copper oxide rectifiers

Once common until replaced by more compact and less costly silicon solid-state rectifiers, these units used stacks of metal plates and took advantage of the semiconductor properties of selenium or copper oxide. ^[6] While selenium rectifiers were lighter in weight and used less power than comparable vacuum tube rectifiers, they had the disadvantage of finite life expectancy, increasing resistance with age, and were only suitable to use at low frequencies. Both selenium and copper oxide rectifiers have somewhat better tolerance of momentary voltage transients than silicon rectifiers.

Typically these rectifiers were made up of stacks of metal plates or washers, held together by a central bolt, with the number of stacks determined by voltage; each cell was rated for about 20 volts. An automotive battery charger rectifier might have only one cell: the high-voltage power supply for a vacuum tube might have dozens of stacked plates. Current density in an air-cooled selenium stack was about 600 mA per square inch of active area (about 90 mA per square centimeter).

Vacuum tube (valve)

Since the discovery of the Edison effect or thermionic emission, various vacuum tube devices have been developed to rectify alternating currents. Low-power devices are used as signal detectors, first used in radio by Fleming in 1904. Many vacuum-tube devices also used vacuum rectifiers in their power supplies, for example the All American Five radio receiver. Vacuum rectifiers were made for very high voltages, such as the high voltage power supply for the cathode ray tube of television receivers, and the kenotron used for power supply in X-ray equipment. However, vacuum rectifiers generally had low current capacity owing to the maximum current density that could be obtained by electrodes heated to temperatures compatible with long life. Another limitation of the vacuum tube rectifier was that the heater power supply often required special arrangements to insulate it from the high voltages of the rectifier circuit.

A rectifier

A rectifier is an electrical device that converts alternating current (AC) to direct current (DC), a process known as rectification. Rectifiers have many uses including as components of power supplies and as detectors of radio signals. Rectifiers may be made of solid state diodes, vacuum tube diodes, mercury arc valves, and other components.

A device which performs the opposite function (converting DC to AC) is known as an inverter.

When only one diode is used to rectify AC (by blocking the negative or positive portion of the waveform), the difference between the term diode and the term rectifier is merely one of usage, i.e., the term rectifier describes a diode that is being used to convert AC to DC. Almost all rectifiers comprise a number of diodes in a specific arrangement for more efficiently converting AC to DC than is possible with only one diode. Before the development of silicon semiconductor rectifiers, vacuum tube diodes and copper(I) oxide or selenium rectifier stacks were used.

Early radio receivers, called crystal radios, used a "cat's whisker" of fine wire pressing on a crystal of galena (lead sulfide) to serve as a point-contact rectifier or "crystal detector". In gas heating systems flame rectification can be used to detect a flame. Two metal electrodes in the outer layer of the flame provide a current path and rectification of an applied alternating voltage, but only while the flame is present.

The Diodes

The Diodes were a Canadian punk/new wave band formed in 1976. They released four albums: Diodes (1977), Released (1979), Action-Reaction (1980), and Survivors (1982). One of the first Toronto bands playing that style of music, The Diodes helped foster the scene in the city. Along with manager Ralph Alfonso, they opened the first Canadian punk nightclub in 1977, called Crash 'n' Burn, where many of the city's punk bands at that time played. The first band to play the club was The Nerves (Peter Case, Jack Lee, Paul Collins), on a double bill with The Diodes. The club was closed at the end of the summer of 1977 due to complaints by the Liberal Party of Ontario (the principal tenants of the building).The club was the subject of a movie by experimental filmmaker Ross McLaren Dialed Crash 'n' Burn, one of the few documents on film of this period. Footage of the club in its heyday also exists in the CBC Television archives because it was the subject of a TV special in 1977. The band put out their first record at this time, a vinyl single featuring Bruce Eves and Amerigo Maras of CEAC. Mickey Skin of all-girl punk band The Curse spews profanity on one side; the Diodes provide musical backing on the other - released on the Crash and Burn label. One side was called "War," the other "Raw," and was one of the first punk records to come out of Toronto. This single was actually an issue of the CEAC Newsletter (published by the Centre For Experimental Art and Communication, the owners of the building that housed the Crash 'n' Burn club).

Resistor

A resistor is a two-terminal electronic component designed to oppose an electric current by producing a voltage drop between its terminals in proportion to the current, that is, in accordance with Ohm's law:

V = IR

Resistors are used as part of electrical networks and electronic circuits. They are extremely commonplace in most electronic equipment. Practical resistors can be made of various compounds and films, as well as resistance wire (wire made of a high-resistivity alloy, such as nickel/chrome).

The primary characteristics of resistors are their resistance and the power they can dissipate. Other characteristics include temperature coefficient, noise, and inductance. Less well-known is critical resistance, the value below which power dissipation limits the maximum permitted current flow, and above which the limit is applied voltage. Critical resistance depends upon the materials constituting the resistor as well as its physical dimensions; it's determined by design.

Resistors can be integrated into hybrid and printed circuits, as well as integrated circuits. Size, and position of leads (or terminals) are relevant to equipment designers; resistors must be physically large enough not to overheat when dissipating their power.

Transistors

The first patent^[1] for the field-effect transistor principle was filed in Canada by Austrian-Hungarian physicist Julius Edgar Lilienfeld on October 22, 1925, but Lilienfeld did not publish any research articles about his devices. In 1934 German physicist Dr. Oskar Heil patented another field-effect transistor.

On 17 November 1947 John Bardeen and Walter Brattain, at AT&T Bell Labs, observed that when electrical contacts were applied to a crystal of germanium, the output power was larger than the input. William Shockley saw the potential in this and worked over the next few months greatly expanding the knowledge of semiconductors and is considered by many to be the "father" of the transistor. The term was coined by John R. Pierce.The transistor is considered by many to be the greatest invention of the twentieth-century,^[2] or as one of the greatest.^[3] It is the key active component in practically all modern electronics. Its importance in today's society rests on its ability to be mass produced using a highly automated process (fabrication) that achieves astonishingly low per-transistor costs.

Although several companies each produce over a billion individually-packaged (known as discrete) transistors every year,^[4] the vast majority of transistors produced are in integrated circuits (often shortened to IC, microchips or simply chips) along with diodes, resistors, capacitors and other electronic components to produce complete electronic circuits. A logic gate consists of about twenty transistors whereas an advanced microprocessor, as of 2006, can use as many as 1.7 billion transistors (MOSFETs).^[5] "About 60 million transistors were built this year [2002] ... for [each] man, woman, and child on Earth."^[6]

Hard disk drive

HDDs record data by magnetizing ferromagnetic material directionally, to represent either a 0 or a 1 binary digit. They read the data back by detecting the magnetization of the material. A typical HDD design consists of a spindle which holds one or more flat circular disks called platters, onto which the data are recorded. The platters are made from a non-magnetic material, usually aluminum alloy or glass, and are coated with a thin layer of magnetic material. Older disks used iron(III) oxide as the magnetic material, but current disks use a cobalt-based alloy.^{[citation needed]}A cross section of the magnetic surface in action. In this case the binary data is encoded using frequency modulation.

The platters are spun at very high speeds. Information is written to a platter as it rotates past devices called read-and-write heads that operate very close (tens of nanometers in new drives) over the magnetic surface. The read-and-write head is used to detect and modify the magnetization of the material immediately under it. There is one head for each magnetic platter surface on the spindle, mounted on a common arm. An actuator arm (or access arm) moves the heads on an arc (roughly radially) across the platters as they spin, allowing each head to access almost the entire surface of the platter as it spins. The arm is moved using a voice coil actuator or in some older designs a stepper motor.

CPU power dissipation

CPU power dissipation or Central processing unit power dissipation is the process in which Central processing units (or CPUs) consume electrical energy, and dissipate this energy by both the action of the switching devices contained in the CPU (such as transistors or vacuum tubes) and via the energy lost in the form of heat due to the resistivity of the electrical circuits. Designing CPUs that perform these tasks efficiently without overheating is a major consideration in nearly all CPU manufacturers to date.

Some implementations of CPUs use very little power, for example, the CPUs in mobile phones often use just a few hundred milliwatts of electricity. In comparison, CPUs in general purpose microcomputers dissipate significantly more power because of their higher complexity and speed. These microelectronic CPUs may consume power in the order of tens of watts. Historically, early CPUs implemented with vacuum tubes consumed power in the order of many kilowatts.

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Bus (computing)

In computer architecture, a bus is a subsystem that transfers data between computer components inside a computer or between computers. Each bus defines its set of connectors to physically plug devices, cards or cables together.

Early computer buses were literally parallel electrical buses with multiple connections, but the term is now used for any physical arrangement that provides the same logical functionality as a parallel electrical bus. Modern computer buses can use both parallel and bit-serial connections, and can be wired in either a multidrop (electrical parallel) or daisy chain topology, or connected by switched hubs, as in the case of USB.

Early computer buses were bundles of wire that attached memory and peripherals. They were named after electrical buses, or busbars. Almost always, there was one bus for memory, and another for peripherals,^{[citation needed]} and these were accessed by separate instructions, with completely different timings and protocols.

One of the first complications was the use of interrupts. Early computers performed I/O by waiting in a loop for the peripheral to become ready. This was a waste of time for programs that had other tasks to do. Also, if the program attempted to perform those other tasks, it might take too long for the program to check again, resulting in loss of data. Engineers thus arranged for the peripherals to interrupt the CPU. The interrupts had to be prioritized, because the CPU can only execute code for one peripheral at a time, and some devices are more time-critical than others.

central processing unit (CPU)

A central processing unit (CPU) or processor is an electronic circuit that can execute computer programs. This broad definition can easily be applied to many early computers that existed long before the term "CPU" ever came into widespread usage. The term itself and its initialism have been in use in the computer industry at least since the early 1960s (Weik 1961). The form, design and implementation of CPUs have changed dramatically since the earliest examples, but their fundamental operation has remained much the same.

Early CPUs were custom-designed as a part of a larger, sometimes one-of-a-kind, computer. However, this costly method of designing custom CPUs for a particular application has largely given way to the development of mass-produced processors that are mkih for one or many purposes. This standardization trend generally began in the era of discrete transistor mainframes and minicomputers and has rapidly accelerated with the popularization of the integrated circuit (IC). The IC has allowed increasingly complex CPUs to be designed and manufactured to tolerances on the order of nanometers. Both the miniaturization and standardization of CPUs have increased the presence of these digital devices in modern life far beyond the limited application of dedicated computing machines. Modern microprocessors appear in everything from automobiles to cell phones to children's toys.

Electronic circuit

An Electronic circuit is a closed path formed by the interconnection of electronic components through which an electric current can flow. The electronic circuits may be physically constructed using any number of methods. Breadboards, perfboards or stripboards are common for testing new designs. Mass-produced circuits are typically built using a printed circuit board (PCB) that is used to mechanically support and electrically connect electronic components.

Electronic circuits can display highly complex behaviors, even though they are governed by the same laws of physics as simpler circuits.

Electronic circuits can usually be categorized as analog, discrete, or mixed-signal (a combination of analog and discrete) electronic circuits.those in which signals may vary continuously with time to correspond to the information being represented. Electronic equipment like voltage amplifiers, power amplifiers, tuning circuits, radios, and televisions are largely analog (with the exception of their control sections, which may be digital, especially in modern units).