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Active Vibration Isolation
''Vibration isolation'' is the prevention of transmission of vibration from one component of a system to others parts of the same system, as in buildings or mechanical systems. Vibration is undesirable in many domains, primarily engineered systems and habitable spaces, and methods have been developed to prevent the transfer of vibration to such systems. Vibrations propagate via mechanical waves and certain mechanical linkages conduct vibrations more efficiently than others. Passive vibration isolation makes use of materials and mechanical linkages that absorb and damp these mechanical waves. Active vibration isolation involves sensors and actuators that produce disruptive interference that cancels-out incoming vibration. Passive isolation "Passive vibration isolation" refers to vibration isolation or mitigation of vibrations by passive techniques such as rubber pads or mechanical springs, as opposed to "active vibration isolation" or "electronic force cancellation" employing electri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vibration
Vibration () is a mechanical phenomenon whereby oscillations occur about an equilibrium point. Vibration may be deterministic if the oscillations can be characterised precisely (e.g. the periodic motion of a pendulum), or random if the oscillations can only be analysed statistically (e.g. the movement of a tire on a gravel road). Vibration can be desirable: for example, the motion of a tuning fork, the reed in a woodwind instrument or harmonica, a mobile phone, or the cone of a loudspeaker. In many cases, however, vibration is undesirable, wasting energy and creating unwanted sound. For example, the vibrational motions of engines, electric motor An electric motor is a machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a electromagnetic coil, wire winding to gene ...s, or any Machine, mechanical device in operation are typically unwanted. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rolloff
Roll-off is the steepness of a transfer function with frequency, particularly in electrical network analysis, and most especially in connection with filter circuits in the transition between a passband and a stopband. It is most typically applied to the insertion loss of the network, but can, in principle, be applied to any relevant function of frequency, and any technology, not just electronics. It is usual to measure roll-off as a function of logarithmic frequency; consequently, the units of roll-off are either decibels per decade (dB/decade), where a decade is a tenfold increase in frequency, or decibels per octave (dB/8ve), where an octave is a twofold increase in frequency. The concept of roll-off stems from the fact that in many networks roll-off tends towards a constant gradient at frequencies well away from the cut-off point of the frequency curve. Roll-off enables the cut-off performance of such a filter network to be reduced to a single number. Note that roll-off ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pneumatic Actuators
A pneumatic control valve actuator converts energy (typically in the form of compressed air) into mechanical motion. The motion can be rotary or linear, depending on the type of actuator. Principle of operation A pneumatic actuator mainly consists of a piston or a diaphragm which develops the motive power. It keeps the air in the upper portion of the cylinder, allowing air pressure to force the diaphragm or piston to move the valve stem or rotate the valve control element. Valves require little pressure to operate and usually double or ''triple'' the input force. The larger the size of the piston, the larger the output pressure can be. Having a larger piston can also be good if the air supply is low, allowing the same forces with less input. These pressures are large enough to crush objects in the pipe. On 100 kPa input, you could lift a small car (upwards of 1,000 lbs) easily, and this is only a basic, small pneumatic valve. However, the resulting forces required of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Motor
A linear motor is an electric motor that has had its stator and rotor (electric), rotor "unrolled", thus, instead of producing a torque (rotation), it produces a linear force along its length. However, linear motors are not necessarily straight. Characteristically, a linear motor's active section has ends, whereas more conventional motors are arranged as a continuous loop. Linear motors are used by the millions in high accuracy CNC machining and in industrial robots. In 2024 this market was USD 1.8 billion. A typical mode of operation is as a Lorentz force, Lorentz-type actuator, in which the applied force is linear equation, linearly proportional to the electric current, current and the magnetic field (\vec F = I \vec L \times \vec B). Many designs have been put forward for linear motors, falling into two major categories, low-acceleration and high-acceleration linear motors. Low-acceleration linear motors are suitable for maglev trains and other ground-based transportation ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interferometer
Interferometry is a technique which uses the '' interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber optics, engineering metrology, optical metrology, oceanography, seismology, spectroscopy (and its applications to chemistry), quantum mechanics, nuclear and particle physics, plasma physics, biomolecular interactions, surface profiling, microfluidics, mechanical stress/strain measurement, velocimetry, optometry, and making holograms. Interferometers are devices that extract information from interference. They are widely used in science and industry for the measurement of microscopic displacements, refractive index changes and surface irregularities. In the case with most interferometers, light from a single source is split into two beams that travel in different optical paths, which are then combined again to produce interference; two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proximity Sensors
A proximity sensor (often simply prox) is a sensor able to detect the presence of nearby objects without any physical contact. A proximity sensor often emits an electromagnetic field or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the field or return signal. The object being sensed is often referred to as the proximity sensor's target. Different proximity sensor targets demand different sensors. For example, a capacitive proximity sensor or photoelectric sensor might be suitable for a plastic target; an inductive proximity sensor always requires a metal target. Proximity sensors can have a high reliability and long functional life because of the absence of mechanical parts and lack of physical contact between the sensor and the sensed object. Proximity sensors are also used in machine vibration monitoring to measure the variation in distance between a shaft and its support bearing. This is common in large steam turbines, compressors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geophone
A geophone is a device that converts ground movement (velocity) into voltage, which may be recorded at a recording station. The Standard deviation, deviation of this measured voltage from the base line is called the seismic response and is analyzed for structure of the Earth. Etymology The term geophone derives from the Greek word "γῆ (ge) " meaning "classical element, earth" and "phone" meaning "sound". Construction Geophones have historically been passive analog circuit, analog devices and typically comprise a spring-mounted wire coil moving within the field of a case-mounted permanent magnet to generate an electrical signal. Recent designs have been based on microelectromechanical systems (MEMS) technology which generates an electrical response to ground motion through an active feedback circuit to maintain the position of a small piece of silicon. The response of a coil/magnet geophone is proportional to ground velocity, while MEMS devices usually respond proportional t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MEM Accelerometer
Mem (also spelled Meem, Meme, or Mim) is the thirteenth letter of the Semitic abjads, including Hebrew ''mēm'' , Aramaic ''mem'' 𐡌, Syriac ''mīm'' ܡ, Arabic ''mīm'' , and Phoenician ''mēm'' 𐤌. Its sound value is . It is also related to the Ancient North Arabian 𐪃, South Arabian , and Ge'ez . The Phoenician letter gave rise to the Greek mu (Μ), Etruscan , Latin M, and Cyrillic М. Origins Mem is believed to derive from the Egyptian hieroglyphic symbol for water, N35 which had been simplified by the Phoenicians and named after their word for "water", ''mem'' (), ultimately coming from Proto-Semitic ''*may-''. Arabic mīm The letter is named ', and is written in several ways depending on its position in the word: Some examples on its uses in Modern Standard Arabic: ''Mīm'' is used in the creation of ''ism'' words (i.e. nouns and adjectives; they are treated fundamentally the same in Arabic grammar). Specifically, ' is used in the creation of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accelerometer
An accelerometer is a device that measures the proper acceleration of an object. Proper acceleration is the acceleration (the rate of change (mathematics), rate of change of velocity) of the object relative to an observer who is in free fall (that is, relative to an inertial frame of reference). Proper acceleration is different from coordinate acceleration, which is acceleration with respect to a given coordinate system, which may or may not be accelerating. For example, an accelerometer at rest on the surface of the Earth will measure an Gravitational acceleration, acceleration due to Earth's gravity straight upwards of about Standard gravity, ''g'' ≈ 9.81 m/s2. By contrast, an accelerometer that is in free fall will measure zero acceleration. Accelerometers have many uses in industry, consumer products, and science. Highly sensitive accelerometers are used in inertial navigation systems for aircraft and missiles. In unmanned aerial vehicles, accelerometers help to stabili ... [...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] |
Micrometre
The micrometre (English in the Commonwealth of Nations, Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System of Units (SI) equalling (SI standard prefix "micro-" = ); that is, one millionth of a metre (or one thousandth of a millimetre, , or about ). The nearest smaller common SI Unit, SI unit is the nanometre, equivalent to one thousandth of a micrometre, one millionth of a millimetre or one billionth of a metre (). The micrometre is a common unit of measurement for wavelengths of infrared radiation as well as sizes of biological cell (biology), cells and bacteria, and for grading wool by the diameter of the fibres. The width of a single human hair ranges from approximately 20 to . Examples Between 1 μm and 10 μm: * 1–10 μm – length of a typical bacterium * 3–8 μm – width of str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actuator
An actuator is a machine element, component of a machine that produces force, torque, or Displacement (geometry), displacement, when an electrical, Pneumatics, pneumatic or Hydraulic fluid, hydraulic input is supplied to it in a system (called an actuating system). The effect is usually produced in a controlled way. An actuator translates such an input signal into the required form of mechanical energy. It is a type of transducer. In simple terms, it is a "mover". An actuator requires a control device (which provides control signal) and a source of energy. The control signal is relatively low in energy and may be voltage, electric current, Compressed air, pneumatic, or hydraulic fluid pressure, or even human power. In the electric, hydraulic, and pneumatic sense, it is a form of automation, automation or automatic control. The displacement achieved is commonly linear or rotational, as exemplified by linear motors and rotary motors, respectively. Rotary motion is more natural for s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
