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Digital Clock
A digital clock displays the time digitally (i.e. in numerals or other symbols), as opposed to an analogue clock. Digital clocks are often associated with electronic drives, but the "digital" description refers only to the display, not to the drive mechanism. (Both analogue and digital clocks can be driven either mechanically or electronically, but "clockwork" mechanisms with digital displays are rare.) History The first digital pocket watch was the invention of Austrian engineer Josef Pallweber who created his "jump-hour" mechanism in 1883. Instead of a conventional dial, the jump-hour featured two windows in an enamel dial, through which the hours and minutes are visible on rotating discs. The second hand remained conventional. By 1885, Pallweber mechanism was already on the market in pocket watches by Cortébert and IWC; arguably contributing to the subsequent rise and commercial success of IWC. The principles of Pallweber jump-hour movement had appeared in wristwatche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz Clock
Quartz clocks and quartz watches are timepieces that use an electronic oscillator regulated by a quartz crystal to keep time. The crystal oscillator, controlled by the resonant mechanical vibrations of the quartz crystal, creates a signal with very precise frequency, so that quartz clocks and watches are at least an order of magnitude more accurate than mechanical clocks. Generally, some form of digital logic counts the cycles of this signal and provides a numerical time display, usually in units of hours, minutes, and seconds. As the advent of solid-state digital electronics in the 1980s allowed them to be made more compact and inexpensive, quartz timekeepers became the world's most widely used timekeeping technology, used in most clocks and watches as well as computers and other appliances that keep time. Explanation Chemically, quartz is a specific form of a compound called silicon dioxide. Many materials can be formed into plates that will resonate. However, quart ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battery (electricity)
An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons. When a battery is connected to an external electric load, those negatively charged electrons flow through the circuit and reach the positive terminal, thus causing a redox reaction by attracting positively charged ions, or cations. Thus, higher energy reactants are converted to lower energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell. Primary (single-use or "disposable") batteries are used once and discarded, as the electrode mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Outage
A power outage, also called a blackout, a power failure, a power blackout, a power loss, a power cut, or a power out is the complete loss of the electrical power network supply to an end user. There are many causes of power failures in an electricity network. Examples of these causes include faults at power stations, damage to Electric power transmission, electric transmission lines, Electrical substation, substations or other parts of the electricity distribution, distribution system, a short circuit, Cascading failure#Cascading failure in power transmission, cascading failure, fuse (electrical), fuse or circuit breaker operation. Power failures are particularly critical at sites where the environment and public safety are at risk. Institutions such as hospitals, Sewage Treatment, sewage treatment plants, and mining, mines will usually have backup power sources such as emergency power system, standby generators, which will automatically start up when electrical power is lost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alarm Clock
An alarm clock or alarm is a clock that is designed to alert an individual or group of people at a specified time. The primary function of these clocks is to awaken people from their night's sleep or short naps; they can sometimes be used for other reminders as well. Most alarm clocks make sounds; some make light or vibration. Some have sensors to identify when a person is in a light stage of sleep, in order to avoid waking someone who is deeply asleep, which causes tiredness, even if the person has had adequate sleep. To turn off the sound or light, a button or handle on the clock is pressed; most clocks automatically turn off the alarm if left unattended long enough. A classic analog alarm clock has an extra Clock face, hand or inset dial that is used to show the time at which the alarm will ring. Alarm clock functions are also used in mobile phones, watches, and computers. Many alarm clocks have radio receivers that can be set to start playing at specified times, and are know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doc (computing)
.doc (an abbreviation of "document") is a filename extension used for word processing documents stored on Microsoft's Proprietary format, proprietary Microsoft Word Binary File Format; it was the primary format for Microsoft Word until the Microsoft Office 2007, 2007 version replaced it with Office Open XML .docx files. Microsoft has used the extension since 1983. Overview Binary file, Binary DOC files often contain more text formatting information (as well as script (computer programming), scripts and undo information) than some other document file formats like Rich Text Format and Hypertext Markup Language, but are usually less widely computer compatibility, compatible. The DOC files created with Microsoft Word versions differ: Word for Windows 1.0 and 2.0 uses a format that was changed in the following Word 6.0 and 95 ("7.0") releases. DOC was changed once again into an Object Linking and Embedding , OLE and Compound File Binary Format , CFBF-based format used from Word 97 ("8 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dot-matrix Display
A dot-matrix display is a low-cost electronic digital display device that displays information on machines such as clocks, watches, calculators, and many other devices requiring a simple alphanumeric (and/or graphic) display device of limited resolution. The display consists of a dot matrix of lights or mechanical indicators arranged in a rectangular configuration (other shapes are also possible, although not common) such that by switching on or off selected dots, text or graphics can be displayed. These displays are normally created using LCD, OLED, or LED technology. A dot-matrix display controller converts instructions from a processor into signals that control the individual dots in the matrix so that the required display is produced. History The dot-matrix display is also known by the obsolete term “punktmatrix display” ( German for dot-matrix) due to the dot matrix being created in Germany by Rudolf Hell in 1925. In September 1977, the US Army wrote up a form to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Split-flap Display
A split-flap display, or sometimes simply a flap display, is a digital electromechanical display device that presents changeable alphanumeric text, and occasionally fixed graphics. They were (from the 1960s to 1990s) commonly used as public transport timetables in airports and railway stations. They were often called Solari boards after the Italian display manufacturer Solari di Udine, or, in Central European countries, Pragotron after the Czech manufacturer. Split-flap displays were once commonly used in consumer digital clocks known as flip clocks. Design Each character position or graphic position has a collection of flaps on which characters or graphics are painted or silkscreened. Larger flaps can display whole words, while smaller flaps display individual characters. The flaps are precisely flipped to display the desired character or graphic. These devices typically show departure or arrival information in railway stations and airports, where they serve as flight ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Numerical Digit
A numerical digit (often shortened to just digit) or numeral is a single symbol used alone (such as "1"), or in combinations (such as "15"), to represent numbers in positional notation, such as the common base 10. The name "digit" originates from the Latin ''digiti'' meaning fingers. For any numeral system with an integer base, the number of different digits required is the absolute value of the base. For example, decimal (base 10) requires ten digits (0 to 9), and binary (base 2) requires only two digits (0 and 1). Bases greater than 10 require more than 10 digits, for instance hexadecimal (base 16) requires 16 digits (usually 0 to 9 and A to F). Overview In a basic digital system, a numeral is a sequence of digits, which may be of arbitrary length. Each position in the sequence has a place value, and each digit has a value. The value of the numeral is computed by multiplying each digit in the sequence by its place value, and summing the results. Di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Fluorescent Display
A vacuum fluorescent display (VFD) is a display device once commonly used on consumer electronics equipment such as video cassette recorders, car audio, car radios, and microwave ovens. A VFD operates on the principle of cathodoluminescence, roughly similar to a cathode-ray tube, but operating at much lower voltages. Each tube in a VFD has a phosphor-coated carbon anode that is bombarded by electrons emitted from the thermionic cathode, cathode filament.Chen, J., Cranton, W., & Fihn, M. (Eds.). (2016). Handbook of Visual Display Technology. doi:10.1007/978-3-319-14346-0 page 1610 onwards In fact, each tube in a VFD is a triode vacuum tube because it also has a mesh control grid. Unlike liquid crystal displays (LCDs), a VFD emits very bright light with high contrast and can support display elements of various colors. Standard illumination figures for VFDs are around 640 Candela per square metre, cd/m2 with high-brightness VFDs operating at 4,000 cd/m2, and experimental un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seven-segment Display
A seven-segment display is a display device for Arabic numerals, less complex than a device that can show more characters such as dot matrix displays. Seven-segment displays are widely used in digital clocks, electronic meters, basic calculators, and other electronic devices that display numerical information. History Seven-segment representation of figures can be found in patents as early as 1903 (in ), when Carl Kinsley invented a method of telegraphically transmitting letters and numbers and having them printed on tape in a segmented format. In 1908, F. W. Wood invented an 8-segment display, which displayed the number 4 using a diagonal bar (). In 1910, a seven-segment display illuminated by incandescent bulbs was used on a power-plant boiler room signal panel. They were also used to show the dialed telephone number to operators during the transition from manual to automatic telephone dialing. They did not achieve widespread use until the advent of light-emitting diode, LEDs in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Clock Changing Numbers
Digital usually refers to something using discrete digits, often binary digits. Businesses *Digital bank, a form of financial institution *Digital Equipment Corporation (DEC) or Digital, a computer company *Digital Research (DR or DRI), a software company Computing and technology Hardware *Digital electronics, electronic circuits which operate using digital signals **Digital camera, which captures and stores digital images *** Digital versus film photography ** Digital computer, a computer that handles information represented by discrete values **Digital recording, information recorded using a digital signal Socioeconomic phenomena * Digital culture, the anthropological dimension of the digital social changes * Digital divide, a form of economic and social inequality in access to or use of information and communication technologies * Digital economy, an economy based on computing and telecommunications resources *Digital rights, legal rights of access to computers or the Internet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
