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Coil Tap
A coil tap is a wiring feature found on some electrical transformers, inductors and coil pickups, all of which are sets of wire coils. The coil tap(s) are points in a wire coil where a conductive patch has been exposed (usually on a loop of wire that extends out of the main coil body). When the coil taps are disconnected, the coil operates as normal (see transformer). When a coil tap is connected to one end of the coil (or the end disconnected and reconnected to the tap), the section of coil between the tap and its connected end is bypassed - effectively reducing the number of turns in the coil. Uses In a transformer, coil taps are often used on both the input and output coils, to compensate for differing supply potential and to provide a range of output potentials respectively. Coil taps on inductors are quite rare, but are sometimes used for band switching in tuning circuits. Coil pickups used with measuring instruments often feature coil taps to compensate for band rejectio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transformer
In electrical engineering, a transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple Electrical network, circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer's core, which induces a varying electromotive force, electromotive force (EMF) across any other coils wound around the same core. Electrical energy can be transferred between separate coils without a metallic (conductive) connection between the two circuits. Faraday's law of induction, discovered in 1831, describes the induced voltage effect in any coil due to a changing magnetic flux encircled by the coil. Transformers are used to change Alternating current, AC voltage levels, such transformers being termed step-up or step-down type to increase or decrease voltage level, respectively. Transformers can also be used to provide galvanic isolation between circuits as well as to couple stages of signa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inductor
An inductor, also called a coil, choke, or reactor, is a Passivity (engineering), passive two-terminal electronic component, electrical component that stores energy in a magnetic field when an electric current flows through it. An inductor typically consists of an insulated wire wound into a Electromagnetic coil, coil. When the current flowing through the coil changes, the time-varying magnetic field induces an electromotive force (''emf'') (voltage) in the conductor, described by Faraday's law of induction. According to Lenz's law, the induced voltage has a polarity (direction) which opposes the change in current that created it. As a result, inductors oppose any changes in current through them. An inductor is characterized by its inductance, which is the ratio of the voltage to the rate of change of current. In the International System of Units (SI), the unit of inductance is the Henry (unit), henry (H) named for 19th century American scientist Joseph Henry. In the measurement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pick Up (music Technology)
A pickup is an electronic device that converts energy from one form to another that captures or senses mechanical vibrations produced by electric instrument, musical instruments, particularly stringed instruments such as the electric guitar, and converts these to an electrical signal that is instrument amplifier, amplified using an instrument amplifier to produce musical sounds through a loudspeaker in a speaker enclosure. The signal from a pickup can also be sound recording, recorded directly. The first electrical string instrument with pickups, the "Frying Pan (guitar), Frying Pan" slide guitar, was created by George Beauchamp and Adolph Rickenbacker around 1931. Most electric guitars and electric basses use Magnet, magnetic pickups. Acoustic guitars, upright basses and fiddles often use a piezoelectric, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conductor (material)
In physics and electrical engineering, a conductor is an object or type of material that allows the flow of charge (electric current) in one or more directions. Materials made of metal are common electrical conductors. The flow of negatively charged electrons generates electric current, positively charged holes, and positive or negative ions in some cases. In order for current to flow within a closed electrical circuit, one charged particle does not need to travel from the component producing the current (the current source) to those consuming it (the loads). Instead, the charged particle simply needs to nudge its neighbor a finite amount, who will nudge ''its'' neighbor, and on and on until a particle is nudged into the consumer, thus powering it. Essentially what is occurring is a long chain of momentum transfer between mobile charge carriers; the Drude model of conduction describes this process more rigorously. This momentum transfer model makes metal an ideal choice fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potential Difference
Voltage, also known as (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to move a positive test charge from the first point to the second point. In the International System of Units (SI), the derived unit for voltage is the ''volt'' (''V''). The voltage between points can be caused by the build-up of electric charge (e.g., a capacitor), and from an electromotive force (e.g., electromagnetic induction in a generator). On a macroscopic scale, a potential difference can be caused by electrochemical processes (e.g., cells and batteries), the pressure-induced piezoelectric effect, and the thermoelectric effect. Since it is the difference in electric potential, it is a physical scalar quantity. A voltmeter can be used to measure the voltage between two points in a system. Often a common reference potential su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuner (radio)
In electronics and radio, a tuner is a type of receiver subsystem that receives RF transmissions, such as AM or FM broadcasts, and converts the selected carrier frequency into a form suitable for further processing or output, such as to an amplifier or loudspeaker. A tuner is also a standalone home audio product, component, or device called an AM/FM tuner or a stereo tuner that is part of a hi-fi or stereo system, or a TV tuner for television broadcasts. The verb ''tuning'' in radio contexts means adjusting the receiver to detect the desired radio signal carrier frequency that a particular radio station uses. Tuners were a major consumer electronics product in the 20th century but in practice are often integrated into other products in the modern day, such as stereo or AV receivers or portable radios. Design history and overview The purpose of a tuner's design is to reduce noise and have a strong ability to amplify the wanted signal. Tuners may be monophonic or s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Band Rejection
Band rejection is a phenomenon in waveform signals, where a certain frequency or range of frequencies are lost or removed from a source signal. The term ''band rejection'', when used in electronic signal processing, refers to the deliberate removal of a known frequency range - for instance, to compensate for a known source of interference (such as noise from mains (household) electricity). A specific frequency is removed using a notch filter. In most other senses, band rejection is the unintentional loss of signal caused by imperfections in the recording, storage or reproduction of a waveform. See also *Band-stop filter *Passband *Stopband A stopband is a band of frequencies, between specified limits, through which a circuit, such as a filter or telephone circuit, does not allow signals to pass, or the attenuation is above the required stopband attenuation level. Depending on app ... References Filter frequency response {{electronics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Impedance
In electrical engineering, impedance is the opposition to alternating current presented by the combined effect of Electrical_resistance, resistance and Electrical_reactance, reactance in a electrical circuit, circuit. Quantitatively, the impedance of a two-terminal Electrical element, circuit element is the ratio of the phasor, complex representation of the Sine wave, sinusoidal voltage between its terminals, to the complex representation of the current flowing through it. In general, it depends upon the frequency of the sinusoidal voltage. Impedance extends the concept of Electrical resistance, resistance to alternating current (AC) circuits, and possesses both Euclidean vector, magnitude and Phase (waves), phase, unlike resistance, which has only magnitude. Impedance can be represented as a complex number, with the same units as resistance, for which the SI unit is the ohm (). Its symbol is usually , and it may be represented by writing its magnitude and phase in the Polar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Tapping
Wiretapping, also known as wire tapping or telephone tapping, is the monitoring of telephone and Internet-based conversations by a third party, often by covert means. The wire tap received its name because, historically, the monitoring connection was an actual electrical tap on an analog telephone or telegraph line. Legal wiretapping by a government agency is also called lawful interception. Passive wiretapping monitors or records the traffic, while active wiretapping alters or otherwise affects it. Legal status Lawful interception is officially strictly controlled in many countries to safeguard privacy; this is the case in all liberal democracies. In theory, telephone tapping often needs to be authorized by a court, and is again in theory, normally only approved when evidence shows it is not possible to detect criminal or subversive activity in less intrusive ways. Oftentimes, the law and regulations require that the crime investigated must be at least of a certain sever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humbucker
A humbucker, humbucking pickup, or double coil, is a guitar pickup that uses two wire coils to cancel out noisy interference from Single coil guitar pickup, coil pickups. Humbucking coils are also used in Microphone, dynamic microphones to cancel electromagnetic hum. Humbuckers are one of two main types of guitar pickups. The other is called a single coil. History The "humbucking coil" was invented in 1934 by Electro-Voice, an American professional audio company based in South Bend, Indiana, that Al Kahn and Lou Burroughs incorporated in 1930 for the purpose of manufacturing portable public address equipment, including microphones and loudspeakers. A twin coiled guitar pickup invented by Arnold Lesti in 1935 is arranged as a humbucker, and the patent USRE20070 describes the noise cancellation and current summation principles of such a design. This "Electric Translating Device" employed the solenoid windings of the pickup to magnetize the steel strings by means of switching o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
