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Piezo-electric
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 mechanical stress. The piezoelectric effect results from the linear electromechanical interaction between the mechanical and electrical states in crystalline materials with no inversion symmetry. The piezoelectric effect is a reversible process: 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 deformed by about 0.1% of the original dimension. Conversely, those same crystals will change about 0.1% of their static dimension when an external electric field is applied. The inverse piezoelectric effect is used in the pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clock Generator
A clock generator is an electronic oscillator that produces a clock signal for use in synchronizing a circuit's operation. The output clock signal can range from a simple symmetrical square wave to more complex arrangements. The basic parts that all clock generators share are a resonant circuit and an amplifier. The resonant circuit is usually a quartz piezo-electric oscillator, although simpler tank circuits and even RC circuits may be used. The amplifier circuit usually inverts the signal from the oscillator and feeds a portion back into the oscillator to maintain oscillation. The generator may have additional sections to modify the basic signal. The 8088 for example, used a 2/3 duty cycle clock, which required the clock generator to incorporate logic to convert the 50/50 duty cycle which is typical of raw oscillators. Other such optional sections include frequency divider or clock multiplier sections. Programmable clock generators allow the number used in the divider o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Piezoelectric Materials
This page lists properties of several commonly used piezoelectric materials. Piezoelectric materials (PMs) can be broadly classified as either crystalline, ceramic, or polymeric. The most commonly produced piezoelectric ceramics are lead zirconate titanate (PZT), barium titanate, and lead titanate. Gallium nitride and zinc oxide can also be regarded as a ceramic due to their relatively wide band gaps. Semiconducting PMs offer features such as compatibility with integrated circuits and semiconductor devices. Inorganic ceramic PMs offer advantages over single crystals, including ease of fabrication into a variety of shapes and sizes not constrained crystallographic directions. Organic polymer PMs, such as PVDF, have low Young's modulus compared to inorganic PMs. Piezoelectric polymers (PVDF, 240 mV-m/N) possess higher piezoelectric stress constants (''g''33), an important parameter in sensors, than ceramics (PZT, 11 mV-m/N), which show that they can be better sensors than ceramics. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead Zirconate Titanate
Lead zirconate titanate, also called lead zirconium titanate and commonly abbreviated as PZT, is an inorganic compound with the chemical formula . It is a ceramic perovskite material that shows a marked piezoelectric effect, meaning that the compound changes shape when an electric field is applied. It is used in a number of practical applications such as ultrasonic transducers and piezoelectric resonators. It is a white to off-white solid. Lead zirconium titanate was first developed around 1952 at the Tokyo Institute of Technology. Compared to barium titanate, a previously discovered metallic-oxide-based piezoelectric material, lead zirconium titanate exhibits greater sensitivity and has a higher operating temperature. Piezoelectric ceramics are chosen for applications because of their physical strength, chemical inertness and their relatively low manufacturing cost. PZT ceramic is the most commonly used piezoelectric ceramic because it has an even greater sensitivity and higher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piezoelectric Balance Presented By Pierre Curie To Lord Kelvin, Hunterian Museum, Glasgow
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] |
Jacques Curie
Jacques Curie (29 October 1855 – 19 February 1941) was a French physicist and professor of mineralogy at the University of Montpellier. Along with his younger brother, Pierre Curie, he studied pyroelectricity in the 1880s, leading to their discovery of some of the mechanisms behind piezoelectricity. He is buried in the Saint-Lazare cemetery in Montpellier. Biography In 1883, Jacques Curie was appointed professor of mineralogy at the University of Montpellier. This appointment marked the end of his collaboration with his brother Pierre. He remained in Montpellier until his death in 1941 with the exception of the years 1887–1889, which he spent in Algeria, teaching at the School of Science of Algiers and conducting his research. It was not until 1903 that he was appointed to the chair of physics, a position he retained until his retirement in 1925. His son Maurice Curie was a physicist. Research and discoveries The major legacy of Jacques Curie is the discovery of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity
Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell's equations. Common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others. The presence of either a positive or negative electric charge produces an electric field. The motion of electric charges is an electric current and produces a magnetic field. In most applications, Coulomb's law determines the force acting on an electric charge. Electric potential is the Work (physics), work done to move an electric charge from one point to another within an electric field, typically measured in volts. Electricity plays a central role in many modern technologies, serving in electric power where electric current is used to energise equipment, and in electronics dealing w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lighters
A lighter is a portable device which uses mechanical or electrical means to create a controlled flame, and can be used to ignite a variety of flammable items, such as cigarettes, butane gas, fireworks, candles, or campfires. A lighter typically consists of a metal or plastic container filled with a flammable liquid, a compressed flammable gas, or in rarer cases a flammable solid (e.g. rope in a trench lighter); a means of ignition to produce the flame; and some provision for extinguishing the flame or else controlling it to such a degree that users may extinguish it with their breath. Alternatively, a lighter can be one that uses electricity to create an electric arc using the created plasma as the source of ignition or a heating element can be used in a similar vein to heat the target to its ignition temperatures, as first formally used by Friedrich Wilhelm Schindler to light cigars and now more commonly seen incorporated into the automobile auxiliary power outlet to igni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Drum
Electronic drums are a modern electronic musical instrument, primarily designed to serve as an alternative to an acoustic drum kit. Electronic drums consist of an electronic sound module which produces the Drum synthesiser, synthesized or Sampler (musical instrument), sampled percussion sounds and a set of ''pads'', usually constructed in a shape to resemble drums and cymbals, which are equipped with electronic sensors to send an electronic signal to the sound module which outputs a sound. Like acoustic drums, the pads are struck by drum sticks and they are played in a similar manner to an acoustic drum kit, albeit with some differences in the drumming experience. The electronic drum (pad/triggering device) is usually sold as part of an electronic drum kit, consisting of a set of drum pads mounted on a stand or rack in a configuration similar to that of an acoustic drum kit layout, with rubberized (Roland corporation, Roland, Yamaha Corporation, Yamaha, Alesis, for example) or spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trigger (drums)
In drumming, a trigger is an electronic transducer that can be attached to a drum, cymbal or other instrument to enable it to control an electronic drum unit or similar device. Specialised triggers are produced for specific instruments. A snare drum The snare drum (or side drum) is a percussion instrument that produces a sharp staccato sound when the head is struck with a drum stick, due to the use of a series of stiff wires held under tension against the lower skin. Snare drums are often u ... trigger, for example, will often have two channels, one each for the rim and head, while a tom-tom drum trigger usually needs to only register strokes to the drum head. Drum triggers gained great attention in the beginning of the 1990s, being extensively used on bass drums in heavy metal music. The advantage of using drum triggers is that potential problems associated with using microphones can be overcome by triggering pre-recorded samples. It is commonly quoted that less effort is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pickup (music Technology)
A pickup is an electronic device that converts energy from one form to another that captures or senses mechanical vibrations produced by musical instruments, particularly stringed instruments such as the electric guitar, and converts these to an electrical signal that is amplified using an instrument amplifier to produce musical sounds through a loudspeaker in a speaker enclosure. The signal from a pickup can also be recorded directly. The first electrical string instrument with pickups, the " Frying Pan" slide guitar, was created by George Beauchamp and Adolph Rickenbacker around 1931. Most electric guitars and electric basses use magnetic pickups. Acoustic guitars, upright basses and fiddles often use a piezo electric pickup. Magnetic pickups A typical magnetic pickup is a transducer (specifically a variable reluctance sensor) that consists of one or more permanent magnets (usually alnico or ferrite) wrapped with a coil of several thousand turns of fine enameled ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atom
Atoms are the basic particles of the chemical elements. An atom consists of a atomic nucleus, nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished from each other by the number of protons that are in their atoms. For example, any atom that contains 11 protons is sodium, and any atom that contains 29 protons is copper. Atoms with the same number of protons but a different number of neutrons are called isotopes of the same element. Atoms are extremely small, typically around 100 picometers across. A human hair is about a million carbon atoms wide. Atoms are smaller than the shortest wavelength of visible light, which means humans cannot see atoms with conventional microscopes. They are so small that accurately predicting their behavior using classical physics is not possible due to quantum mechanics, quantum effects. More than 99.94% of an atom's mass is in the nucleus. Protons hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scanning Probe Microscopy
Scanning probe microscopy (SPM) is a branch of microscopy that forms images of surfaces using a physical probe that scans the specimen. SPM was founded in 1981, with the invention of the scanning tunneling microscope, an instrument for imaging surfaces at the atomic level. The first successful scanning tunneling microscope experiment was done by Gerd Binnig and Heinrich Rohrer. The key to their success was using a feedback loop to regulate gap distance between the sample and the probe. Many scanning probe microscopes can image several interactions simultaneously. The manner of using these interactions to obtain an image is generally called a mode. The resolution varies somewhat from technique to technique, but some probe techniques reach a rather impressive atomic resolution. This is largely because piezoelectricity, piezoelectric actuators can execute motions with a precision and accuracy at the atomic level or better on electronic command. This family of techniques can be cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
