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Buzzer
A buzzer or beeper is an audio signaling device, which may be mechanical, electromechanical, or piezoelectric (''piezo'' for short). Typical uses of buzzers and beepers include alarm devices, timers, train and confirmation of user input such as a mouse click or keystroke. History Electromechanical The electric buzzer was invented in 1831 by Joseph Henry. They were mainly used in early doorbells until they were phased out in the early 1930s in favor of musical chimes, which had a softer tone. Piezoelectric Piezoelectric buzzers, or piezo buzzers, as they are sometimes called, were invented by Japanese manufacturers and fitted into a wide array of products during the 1970s to 1980s. This advancement mainly came about because of cooperative efforts by Japanese manufacturing companies. In 1951, they established the Barium Titanate Application Research Committee, which allowed the companies to be "competitively cooperative" and bring about several piezoelectric innovati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buzzer Interior
A buzzer or beeper is an audio signaling device, which may be mechanical, electromechanical, or piezoelectric (''piezo'' for short). Typical uses of buzzers and beepers include alarm devices, timers, train and confirmation of user input such as a mouse click or keystroke. History Electromechanical The electric buzzer was invented in 1831 by Joseph Henry. They were mainly used in early doorbells until they were phased out in the early 1930s in favor of musical chimes, which had a softer tone. Piezoelectric Piezoelectric buzzers, or piezo buzzers, as they are sometimes called, were invented by Japanese manufacturers and fitted into a wide array of products during the 1970s to 1980s. This advancement mainly came about because of cooperative efforts by Japanese manufacturing companies. In 1951, they established the Barium Titanate Application Research Committee, which allowed the companies to be "competitively cooperative" and bring about several piezoelectric innovations and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joy Buzzer
A joy buzzer (also called a hand buzzer) is a practical joke device that consists of a coiled mainspring inside a disc worn in the palm of the hand. When the wearer shakes hands with another person, a button on the disc releases the spring, which rapidly unwinds creating a vibration that mimics an electric shock to the unsuspecting victim. History The joy buzzer was invented in 1928 by Soren Sorensen Adams, Soren Sorensen "Sam" Adams of the S.S. Adams Co. It was modeled after ''The Zapper'', a product that was similar to the joy buzzer, but did not have a very effective buzz and contained a button with a blunt point that would hurt the recipient's hand. Adams brought a large prototype of his newly designed buzzer to Dresden, Germany, where a machinist created the tools that would make the parts for a new palm-sized Joy Buzzer. In 1932, the item received from the United States Patent and Trademark Office, U.S. Patent Office. The instant success of the new item allowed Adams to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Bell
An electric bell is a mechanical or electronic bell that functions by means of an electromagnet. When an electric current is applied, it produces a repetitive buzzing, clanging or ringing sound. Electromechanical bells have been widely used at railroad crossings, in telephones, fire and burglar alarms, as school bells, doorbells, and alarms in industrial areas, since the late 1800s, but they are now being widely replaced with electronic sounders. An electric bell consists of one or more electromagnets, made of a coil of insulated wire around an iron bar, which attract an iron strip armature with a clapper. Types Interrupter bells How they work The most widely used form is the interrupter bell, which is a mechanical bell that produces a continuous sound when current is applied. See animation, above. The bell or gong ''(B)'', which is often in the shape of a cup or half-sphere, is struck by a spring-loaded arm ''(A)'' with a metal ball on the end called a clapper, actua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piezoelectric
Piezoelectricity (, ) is the electric charge that accumulates in certain solid materials—such as crystals, certain ceramics, and biological matter such as bone, DNA, and various proteins—in response to applied stress (mechanics), mechanical stress. The piezoelectric effect results from the linear electromechanical interaction between the mechanical and electrical states in crystalline materials with no centrosymmetry, inversion symmetry. The piezoelectric effect is a reversible process (thermodynamics), reversible process: List of piezoelectric materials, materials exhibiting the piezoelectric effect also exhibit the reverse piezoelectric effect, the internal generation of a mechanical strain resulting from an applied electric field. For example, lead zirconate titanate crystals will generate measurable piezoelectricity when their static structure is Deformation (physics), deformed by about 0.1% of the original dimension. Conversely, those same crystals will change about 0.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doorbell
A doorbell is a signaling device typically placed near a door to a building's entrance. When a visitor presses a button (control), button, the bell rings inside the building, alerting the occupant to the presence of the visitor. Although the first doorbells were mechanical, activated by pulling a cord connected to a bell, modern doorbells are electric, operated by a pushbutton switch. Modern doorbells often incorporate intercoms and miniature video cameras to increase security. History William Murdoch, a Scottish inventor, installed a number of his own innovations in his house, built in Birmingham in 1817; one of these was a loud doorbell, that worked using a piped system of compressed air. A precursor to the electric doorbell, specifically a bell that could be rung at a distance via an electric wire, was invented by Joseph Henry around 1831. By the early 1900s, electric doorbells had become commonplace. Wired doorbells In most wired systems, a button on the outside next ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helmholtz Resonance
Helmholtz resonance, also known as wind throb, refers to the phenomenon of air resonance in a cavity, an effect named after the German physicist Hermann von Helmholtz. This type of resonance occurs when air is forced in and out of a cavity (the resonance chamber), causing the air inside to vibrate at a specific natural frequency. The principle is widely observable in everyday life, notably when blowing across the top of a bottle, resulting in a resonant tone. The concept of Helmholtz resonance is fundamental in various fields, including acoustics, engineering, and physics. The resonator itself, termed a ''Helmholtz resonator'', consists of two key components: a cavity and a neck. The size and shape of these components are crucial in determining the resonant frequency, which is the frequency at which the system naturally oscillates. In the context of acoustics, Helmholtz resonance is instrumental in the design and analysis of musical instruments, architectural acoustics, and soun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alarms
An alarm device is a mechanism that gives an audible, visual, combination, or other kind of alarm signal to alert someone to a problem or condition that requires urgent attention. Etymology The word ''alarm'' comes from the Old French ''a l'arme'' meaning "to the arms", or "to the weapons", telling armed men to pick up their weapons and get ready for action because an enemy may have suddenly appeared. The word ''alarum'' is an archaic form of ''alarm''. It was sometimes used as a call to arms in the stage directions of Italian ''all'armi'' and appears 89 times in Shakespeare's First Folio">William Shakespeare">Shakespeare's First Folio. Often explained as the off-stage sounds of conflict or disturbance, recent research suggests a bell or drum may have been used to rouse soldiers from sleep. History and development Early alarm devices were often bells, drums, other musical instruments, or any items which made unusual loud noises that attracted the attention of the surroundin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sport
Sport is a physical activity or game, often Competition, competitive and organization, organized, that maintains or improves physical ability and skills. Sport may provide enjoyment to participants and entertainment to spectators. The number of participants in a particular sport can vary from hundreds of people to a single individual. Sport competitions may use a team or single person format, and may be Open (sport), open, allowing a broad range of participants, or closed, restricting participation to specific groups or those invited. Competitions may allow a "tie" or "draw", in which there is no single winner; others provide tie-breaking methods to ensure there is only one winner. They also may be arranged in a tournament format, producing a champion. Many sports leagues make an annual champion by arranging games in a regular sports season, followed in some cases by playoffs. Sport is generally recognised as system of activities based in physical athleticism or physical de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Major Appliance
A major appliance is a non-portable or semi-portable machine used for routine housekeeping tasks such as cooking, washing laundry, or food preservation. Such appliances are sometimes collectively known as white goods, as the products were traditionally white in color, although a variety of colors are now available. An appliance is different from a plumbing fixture because it uses electricity or fuel. Major appliances differ from small appliances because they are bigger and not portable. They are often considered fixtures and part of real estate and as such they are often supplied to tenants as part of otherwise unfurnished rental properties. Major appliances may have special electrical connections, connections to gas supplies, or special plumbing and ventilation arrangements that may be permanently connected to the appliance. This limits where they can be placed in a home. Since major appliances in a home consume a significant amount of energy, they have become the objective ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microwave Oven
A microwave oven, or simply microwave, is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. This induces Dipole#Molecular dipoles, polar molecules in the food to rotate and produce thermal energy (heat) in a process known as dielectric heating. Microwave ovens heat food quickly and efficiently because the heating effect is fairly uniform in the outer of a homogeneous, high-water-content food item. The development of the cavity magnetron in the United Kingdom made possible the production of electromagnetic waves of a small enough wavelength (microwaves) to efficiently heat up water molecules. American electrical engineer Percy Spencer is generally credited with developing and patenting the world's first commercial microwave oven, the "Radarange", which was first sold in 1947. He based it on British radar technology which had been developed before and during World War II. Raytheon later licensed its patents ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lock-out Device
''Jeopardy!'' is an American television game show created by Merv Griffin. The show is a quiz competition that reverses the traditional question-and-answer format of many quiz shows. Rather than being given questions, contestants are instead given general knowledge clues in the form of answers and they must identify the person, place, thing, or idea that the clue describes, phrasing each response in the form of a question. The original daytime version debuted on NBC on March 30, 1964, and aired until January 3, 1975. A nighttime Broadcast syndication, syndicated edition aired weekly from September 1974 to September 1975, and a revival, ''The All-New Jeopardy!'', ran on NBC from October 1978 to March 1979 on weekdays. The syndicated show familiar to modern viewers and aired daily (currently by Sony Pictures Television) premiered on September 10, 1984. Art Fleming served as host for all versions of the show between 1964 and 1979. Don Pardo served as announcer until 1975, and Joh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
