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Stop Action Magnet
The stop action magnet, usually abbreviated to SAM, is an electromagnetic device used for the control of pipe organs and virtual pipe organs, and forms part of the organ's combination action. On a classical organ the device may be referred to as a drawstop solenoid. The SAM can be considered an electrical relay, the difference being that the SAM also has a drawknob or a tab, which enables it to be operated manually as well as electrically. A SAM will have an armature which is operated by an electrically induced magnetic field and dependent on whether the SAM is being used with a drawknob or a tilting tablet on a classically voiced organ or with a flat tab on a theatre organ, the armature will move in either a linear fashion or with semi-circular movement, in a small defined arc. A drawknob or tab is attached to the armature to facilitate hand operation. Each SAM consists of two coils of wire, wound on bobbins, which surround a single central, magnetically conductive pole piece or t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pipe Organ
The pipe organ is a musical instrument that produces sound by driving pressurized air (called ''wind'') through the organ pipes selected from a keyboard. Because each pipe produces a single pitch, the pipes are provided in sets called ''ranks'', each of which has a common timbre and volume throughout the keyboard compass. Most organs have many ranks of pipes of differing timbre, pitch, and volume that the player can employ singly or in combination through the use of controls called stops. A pipe organ has one or more keyboards (called '' manuals'') played by the hands, and a pedal clavier played by the feet; each keyboard controls its own division, or group of stops. The keyboard(s), pedalboard, and stops are housed in the organ's ''console''. The organ's continuous supply of wind allows it to sustain notes for as long as the corresponding keys are pressed, unlike the piano and harpsichord whose sound begins to dissipate immediately after a key is depressed. The smallest po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combination Action
Registration is the technique of choosing and combining the stops of a pipe organ in order to produce a particular sound. ''Registration'' can also refer to a particular combination of stops, which may be recalled through combination action. The registration chosen for a particular piece will be determined by a number of factors, including the composer's indications (if any are given), the time and place in which the piece was composed, the organ the piece is played upon, and the acoustic environment within which the organ resides. Pitch and timbre The pitch produced by a pipe is a function of its length. An organ stop may be tuned to sound (or "speak at") the pitch normally associated with the key that is pressed (the "unison pitch"), or it may speak at a fixed interval above or below this pitch (an "octave pitch"). Some stops are tuned to notes "in-between" the octaves and are called "Mutations" (see below). The pitch of a rank of pipes is denoted by a number on the stop knob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relay
A relay Electromechanical relay schematic showing a control coil, four pairs of normally open and one pair of normally closed contacts An automotive-style miniature relay with the dust cover taken off A relay is an electrically operated switch. It consists of a set of input terminals for a single or multiple control signals, and a set of operating contact terminals. The switch may have any number of contacts in multiple contact forms, such as make contacts, break contacts, or combinations thereof. Relays are used where it is necessary to control a circuit by an independent low-power signal, or where several circuits must be controlled by one signal. Relays were first used in long-distance telegraph circuits as signal repeaters: they refresh the signal coming in from one circuit by transmitting it on another circuit. Relays were used extensively in telephone exchanges and early computers to perform logical operations. The traditional form of a relay uses an electromagnet to c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theatre Organ
A theatre organ (also known as a theater organ, or, especially in the United Kingdom, a cinema organ) is a type of pipe organ developed to accompany silent films, from the 1900s to the 1920s. Theatre organs have horseshoe-shaped arrangements of stop tabs (tongue-shaped switches) above and around the instrument's keyboards on their consoles. Theatre organ consoles were typically decorated with brightly colored stop tabs, with built-in console lighting. Organs in the UK had a common feature: large translucent surrounds extending from both sides of the console, with internal colored lighting. Theatre organs began to be installed in other venues, such as civic auditoriums, sports arenas, private residences, and churches. One of the largest theatre organs ever built was the 6 manual 52 rank Barton installed in the Chicago Stadium. There were over 7,000 such organs installed in America and elsewhere from 1915 to 1933, but fewer than 40 instruments remain in their original venues. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reed Switch
Reed or Reeds may refer to: Science, technology, biology, and medicine * Reed bird (other) * Reed pen, writing implement in use since ancient times * Reed (plant), one of several tall, grass-like wetland plants of the order Poales * Reed reaction, in chemistry * Reed receiver, an outdated form of multi-channel signal decoding * Reed relay, one or more reed switches controlled by an electromagnet * Reed switch, an electrical switch operated by an applied magnetic field * Reed valve, restricts the flow of fluids to a single direction * Reed (weaving), a comb like tool for beating the weft when weaving * Reed's law, describes the utility of large networks, particularly social networks * Reed–Solomon error correction, a systematic way of building codes that can be used to detect and correct multiple random symbol errors * Reed–Sternberg cell, related to Hodgkin's disease Organizations * Reed (company), offering employment-related services (UK) * Reed and Stem, former ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ampere
The ampere (, ; symbol: A), often shortened to amp,SI supports only the use of symbols and deprecates the use of abbreviations for units. is the unit of electric current in the International System of Units (SI). One ampere is equal to electrons worth of charge moving past a point in a second. It is named after French mathematician and physicist André-Marie Ampère (1775–1836), considered the father of electromagnetism along with Danish physicist Hans Christian Ørsted. As of the 2019 redefinition of the SI base units, the ampere is defined by fixing the elementary charge to be exactly C ( coulomb), which means an ampere is an electrical current equivalent to elementary charges moving every seconds or elementary charges moving in a second. Prior to the redefinition the ampere was defined as the current that would need to be passed through 2 parallel wires 1 metre apart to produce a magnetic force of newtons per metre. The earlier CGS system had two definitio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnet
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a coil. A current through the wire creates a magnetic field which is concentrated in the hole in the center of the coil. The magnetic field disappears when the current is turned off. The wire turns are often wound around a magnetic core made from a ferromagnetic or ferrimagnetic material such as iron; the magnetic core concentrates the magnetic flux and makes a more powerful magnet. The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field. Electromagnets are widely used as components of other electrical devices, such as motors, generators, electromechanical solen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
