Electronic devices have hugely influenced the development of many aspects of modern society, such as telecommunications, entertainment, education, health care, industry, and security. The main driving force behind the advancement of electronics is the semiconductor industry, which in response to global demand continually produces ever-more sophisticated electronic devices and circuits. The semiconductor industry is one of the largest and most profitable sectors in the global economy, with annual revenues exceeding $481 billion in 2018. The electronics industry also encompasses other sectors that rely on electronic devices and systems, such as e-commerce, which generated over $29 trillion in online sales in 2017. (Full article...)
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The JBL D44000 Paragon is a one-piece stereo loudspeaker created by JBL that was introduced in 1957 and discontinued in 1983; its production run was the longest of any JBL speaker. At its launch, the Paragon was the most expensive domestic loudspeaker on the market.
Designed by Arnold Wolf from a concept elaborated by Richard Ranger, it is almost 9 feet (2.7 m) long and requires over a hundred-man hours of hand-finishing by a team of dedicated craftsmen. Resembling less a conventional loudspeaker than an elegant sideboard, it is a landmark product for the company that was sought after by the well-heeled and by celebrities. With an estimated total production of about 1,000 units, it is highly sought after by collectors to this day. (Full article...)
The image method of filter design determines the properties of filter sections by calculating the properties they would have in an infinite chain of identical sections. In this, the analysis parallels transmission line theory on which it is based. Filters designed by this method are called image parameter filters, or just image filters. An important parameter of image filters is their image impedance, the impedance of an infinite chain of identical sections. (Full article...)
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Sinclair Executive Type 1
The Sinclair Executive was the world's first "slimline" pocket calculator, and the first to be produced by Clive Sinclair's company Sinclair Radionics. Introduced in 1972, the calculator was produced in at least two versions with different keyboard markings; a variant called the Sinclair Executive Memory was introduced in 1973.
Its small size was made possible by pulsing current to the Texas Instruments TMS1802 "calculator on a chip" integrated circuit, reducing the power consumption more than tenfold. The Executive was highly successful, making £1.8 million of profit for Sinclair and winning a Design Council Award for Electronics. (Full article...)
The actual impedance may vary quite considerably from the nominal figure with changes in frequency. In the case of cables and other transmission lines, there is also variation along the length of the cable, if it is not properly terminated. (Full article...)
HDMI implements the ANSI/CTA-861 standard, which defines video formats and waveforms, transport of compressed and uncompressed LPCM audio, auxiliary data, and implementations of the VESA EDID. CEA-861 signals carried by HDMI are electrically compatible with the CEA-861 signals used by the Digital Visual Interface (DVI). No signal conversion is necessary, nor is there a loss of video quality when a DVI-to-HDMI adapter is used. The Consumer Electronics Control (CEC) capability allows HDMI devices to control each other when necessary and allows the user to operate multiple devices with one handheld remote control device. (Full article...)
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The Sinclair Sovereign was a high-end calculator introduced by Clive Sinclair's company Sinclair Radionics in 1976. It was an attempt to escape from the unprofitable low end of the market, and one of the last calculators Sinclair produced. Made with a case of pressed steel that a variety of finishes, it cost between £30 and £60 at a time when other calculators could be purchased for under £5. A number of factors meant that the Sovereign was not a commercial success, including the cost, high import levies on components, competition from cheaper calculators manufactured abroad, and the development of more power-efficient designs using liquid-crystal displays. Though it came with a five-year guarantee, issues such as short battery life limited its usefulness. The company moved on to producing computers soon afterwards.
The impedance analogy is a method of representing a mechanical system by an analogous electrical system. The advantage of doing this is that there is a large body of theory and analysis techniques concerning complex electrical systems, especially in the field of filters. By converting to an electrical representation, these tools in the electrical domain can be directly applied to a mechanical system without modification. A further advantage occurs in electromechanical systems: Converting the mechanical part of such a system into the electrical domain allows the entire system to be analysed as a unified whole.
The mathematical behaviour of the simulated electrical system is identical to the mathematical behaviour of the represented mechanical system. Each element in the electrical domain has a corresponding element in the mechanical domain with an analogous constitutive equation. All laws of circuit analysis, such as Kirchhoff's circuit laws, that apply in the electrical domain also apply to the mechanical impedance analogy. (Full article...)
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A signal travelling along an electrical transmission line will be partly, or wholly, reflected back in the opposite direction when the travelling signal encounters a discontinuity in the characteristic impedance of the line, or if the far end of the line is not terminated in its characteristic impedance. This can happen, for instance, if two lengths of dissimilar transmission lines are joined.
This article is about signal reflections on electrically conducting lines. Such lines are loosely referred to as copper lines, and indeed, in telecommunications are generally made from copper, but other metals are used, notably aluminium in power lines. Although this article is limited to describing reflections on conducting lines, this is essentially the same phenomenon as optical reflections in fibre-optic lines and microwave reflections in waveguides. (Full article...)
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The first-generation iPad (/ˈaɪpæd/; EYE-pad) (retrospectively referred to unofficially as the iPad 1 or original iPad) is a tablet computer designed and marketed by Apple Inc. as the first device in the iPad lineup of tablet computers. The device features an Apple A4SoC, a 9.7 in (250 mm) touchscreen display, and, on certain variants, the capability of accessing cellular networks. Using the iOS operating system, the iPad can play music, send and receive email and browse the web. Other functions, which include the ability to play games and access references, GPS navigation software and social network services can be enabled by downloading apps.
The device was announced and unveiled on January 27, 2010, by Apple founder Steve Jobs at an Apple press event. On April 3, 2010, the Wi-Fi variant of the device was released in the United States, followed by the release of the "Wi-Fi + 3G" variant on April 30. On May 28, 2010, it was released in Australia, Canada, France, Japan, Italy, Germany, Spain, Switzerland and the United Kingdom. (Full article...)
There is a critical value of transformer coupling coefficient at which the frequency response of the amplifier is maximally flat in the passband and the gain is maximum at the resonant frequency. Designs frequently use a coupling greater than this (over-coupling) in order to achieve an even wider bandwidth at the expense of a small loss of gain in the centre of the passband. (Full article...)
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The Samsung Galaxy S III (unofficially known as the Samsung Galaxy S3) is an Androidsmartphone designed, developed, and marketed by Samsung Electronics. Launched in 2012, it had sold more than 80 million units overall, making it the most sold phone in the S series. It is the third smartphone in the Samsung Galaxy S series.
It is distinguished from its predecessor by its larger and higher-resolution screen, higher storage options, a larger battery, and a video camera with stereo audio recording for a spatial effect on headphones and external speakers. While the picture and video resolutions of the camera stayed the same, its launching speed and shutter lag improved. (Full article...)
The iPhone 5s maintained almost the same external design as its predecessor, the iPhone 5, although the 5s received a new white/gold color scheme in addition to white/silver and space gray/black. The 5s has vastly upgraded internal hardware, however. It introduced the A7 64-bit dual-core system-on-chip, the first 64-bit processor to be used on a smartphone, accompanied by the M7 "motion co-processor". A redesigned home button with Touch ID, a fingerprint recognition system which can be used to unlock the phone and authenticate App Store and iTunes Store purchases, was also introduced. The camera was also updated with a larger aperture and a dual-LED flash optimized for different color temperatures. Earphones known as EarPods were included with the 5s, and Apple released accessories including a case and a dock. It had a 4-inch display, similar to the iPhone 5 and iPhone 5c. (Full article...)
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The Nakamichi Dragon is an audio cassette deck that was introduced by Nakamichi in 1982 and marketed until 1994. The Dragon was the first Nakamichi model with bidirectional replay capability and the world's first production tape recorder with an automatic azimuth correction system; this feature, which was invented by Philips engineers and improved by Niro Nakamichi, continuously adjusts the azimuth of the replay head to minimize apparent head skew and correctly reproduce the treble signal present on the tape. The system allows the correct reproduction of mechanically skewed cassettes and recordings made on misaligned decks. Apart from the Dragon, similar systems have only been used in the Nakamichi TD-1200 car cassette player and the Marantz SD-930 cassette deck.
At the time of its introduction, the Dragon had the lowest-ever wow and flutter and the highest-ever dynamic range, losing marginally to the former Nakamichi flagship the 1000ZXL in frequency response. Competing models by Sony, Studer, Tandberg and TEAC that were introduced later in the 1980s sometimes surpassed the Dragon in mechanical quality and feature set but none could deliver the same mix of sound quality, flexibility and technological advancement. The Dragon, despite inherent issues with long-term reliability, remained the highest point of compact cassette technology. (Full article...)
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The NAD 3020 is a stereo integrated amplifier by NAD Electronics, considered to be one of the most important components in the history of high fidelity audio. Launched in 1978, this highly affordable product delivered a good quality sound, which acquired a reputation as an audiophile amplifier of exceptional value. By 1998, the NAD 3020 had become the most well known and best-selling audio amplifier in history. (Full article...)
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The LS3/5A (each element pronounced separately, without the stroke) is a small studio monitor loudspeaker originated by the BBC for use by outside broadcast vans to ensure quality of their broadcasts. The speaker concept set out transparent and natural sound as the goal, and the achievement of the result is widely acknowledged.
The BBC granted licences to a small number of British firms, who first manufactured the product in 1975. The product underwent a change in 1987 due to consistency issues in manufacturing, and again in around 2003 when original parts from KEF ran out. Upwards of 60,000 pairs of the speaker have been sold. Reviewers have recognised its enormous importance as a bookshelf design. (Full article...)
The magnitude of the electrostatic force between two point charges is directly proportional to the magnitudes of each charge and inversely proportional to the square of the distance between the charges.
For calculating the direction and magnitude of the force simultaneously, one will wish to consult the full vector version of the Law
where is the electrostatic force vector, is the charge on which the force acts, is the acting charge, is the distance vector between the two charges, is position vector of , is position vector of , is a unit vector pointing in the direction of , and is a constant called the permittivity of free space.
This vector equation indicates that opposite charges attract, and like charges repel. When is negative, the force is attractive. When positive, the force is repulsive.
A glucose meter is a medical device for determining the approximate concentration of glucose in the blood. It is a key element of home blood glucose monitoring by people with diabetes mellitus or with proneness to hypoglycemia. A small drop of blood obtained by pricking the skin with a lancet is placed on a disposable test strip, which the meter reads and uses to calculate the blood glucose level. The meter then displays the level in mg/dl or mmol/l.