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Contact Breaker
A contact breaker (or "points") is a type of electrical switch, found in the ignition systems of spark-ignition internal combustion engines. The switch is automatically operated by a cam driven by the engine. The timing of operation of the switch is set so that a spark is produced at the right time to ignite the compressed air/fuel mixture in the cylinder of the engine. A mechanism may be provided to slightly adjust timing to allow for varying load on the engine. Since these contacts operate frequently, they are subject to wear, causing erratic ignition of the engine. More recent engines use electronic means to trigger the spark, which eliminated contact wear and allows computer control of ignition timing. Purpose The purpose of the contact breaker is to interrupt the current flowing in the primary winding of the ignition coil. When the current stops flowing, the resulting collapse of the magnetic field in the primary winding induces a high voltage in the secondary winding. Thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Servomechanism
In mechanical and control engineering, a servomechanism (also called servo system, or simply servo) is a control system for the position and its time derivatives, such as velocity, of a mechanical system. It often includes a servomotor, and uses closed-loop control to reduce steady-state error and improve dynamic response. In closed-loop control, error-sensing negative feedback is used to correct the action of the mechanism. In displacement-controlled applications, it usually includes a built-in encoder or other position feedback mechanism to ensure the output is achieving the desired effect. Following a specified motion trajectory is called servoing, where "servo" is used as a verb. The ''servo'' prefix originates from the Latin word ''servus'' meaning slave. The term correctly applies only to systems where the feedback or error-correction signals help control mechanical position, speed, attitude or any other measurable variables. For example, an automotive power win ... [...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 has a set of input terminals for one or more 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 to control a circuit by an independent low-power signal and to control several circuits by one signal. They were first used in long-distance telegraph circuits as signal repeaters that transmit a refreshed copy of the incoming signal onto another circuit. Relays were used extensively in telephone exchanges and early computers to perform logical operations. The traditional electromechanical relay uses an electromagnet to close or open the contacts, but relays using other operati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contactor
A contactor is an electrically controlled switch used for switching an electrical power circuit. A contactor is typically controlled by a circuit which has a much lower power level than the switched circuit, such as a 24-volt coil electromagnet controlling a 230-volt motor switch. Unlike general-purpose relays, contactors are designed to be directly connected to high-current load devices. Relays tend to be of lower capacity and are usually designed for both ''normally closed'' and ''normally open'' applications. Devices switching more than 15 amperes or in circuits rated more than a few kilowatts are usually called contactors. Apart from optional auxiliary low-current contacts, contactors are almost exclusively fitted with normally open ("form A") contacts. Unlike relays, contactors are designed with features to control and suppress the arc produced when interrupting heavy motor currents. Unlike a circuit breaker, a contactor is not intended to interrupt a short circuit curren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ignition Magneto
An ignition magneto (also called a high-tension magneto) is an older type of ignition system used in spark-ignition engines (such as petrol engines). It uses a magneto and a transformer to make pulses of high voltage for the spark plugs. The older term "high-tension" means "high-voltage". Design A simple magneto (an electrical generator using permanent magnets) is able to produce relatively low voltage electricity, however it is unable to produce the high voltages required by a spark plug as used in most modern engines (aside from diesel engines). An ''ignition magneto'' also includes an electrical transformer, which converts the electricity to a higher voltage (with the trade-off being a corresponding reduction in the output electric current, current). As the points begin to open, point spacing is initially such that the voltage across the primary coil would arc across the points. A capacitor is placed across the points which absorbs the energy stored in the leakage inductanc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensor
A sensor is often defined as a device that receives and responds to a signal or stimulus. The stimulus is the quantity, property, or condition that is sensed and converted into electrical signal. In the broadest definition, a sensor is a device, module, machine, or subsystem that detects events or changes in its environment and sends the information to other electronics, frequently a computer processor. Sensors are used in everyday objects such as touch-sensitive elevator buttons ( tactile sensor) and lamps which dim or brighten by touching the base, and in innumerable applications of which most people are never aware. With advances in micromachinery and easy-to-use microcontroller platforms, the uses of sensors have expanded beyond the traditional fields of temperature, pressure and flow measurement, for example into MARG sensors. Analog sensors such as potentiometers and force-sensing resistors are still widely used. Their applications include manufacturing and machinery ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hall Effect
The Hall effect is the production of a voltage, potential difference (the Hall voltage) across an electrical conductor that is wikt:transverse, transverse to an electric current in the conductor and to an applied magnetic field wikt:perpendicular, perpendicular to the current. It was discovered by Edwin Hall in 1879. The ''Hall coefficient'' is defined as the ratio of the induced electric field to the product of the current density and the applied magnetic field. It is a characteristic of the material from which the conductor is made, since its value depends on the type, number, and properties of the charge carriers that constitute the current. Discovery Wires carrying current in a magnetic field experience a mechanical force perpendicular to both the current and magnetic field. In the 1820s, André-Marie Ampère observed this underlying mechanism that led to the discovery of the Hall effect. However it was not until a solid mathematical basis for electromagnetism was system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnet
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets. A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include the elements iron, nickel and cobalt and their alloys, some alloys of rare-earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retro
Retro style is imitative or consciously derivative of lifestyles, trends, or art forms from the past, including in music, modes, fashions, or attitudes. It has been argued that there is a nostalgia cycle in popular culture. Definition The term ''retro'' has been in use since 1972 to describe on the one hand, new artifacts that self-consciously refer to particular modes, motifs, techniques, and materials of the past.Dermody, Breathnach 2009, p. 7 But on the other hand, many people use the term to categorize styles that have been created in the past.Baker 2012, p. 622 Retro style refers to new things that display characteristics of the past. Unlike the historicism of the Romantic generations, it is mostly the recent past that retro seeks to recapitulate, focusing on the products, fashions, and artistic styles produced since the Industrial Revolution, the successive styles of Modernity. The English word ''retro'' derives from the Latin prefix ''retro'', meaning backwards, or in p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timing Light
A timing light is a stroboscope used to dynamically set the ignition timing of an Otto cycle or similar internal combustion engine equipped with a distributor. Modern electronically controlled passenger vehicle engines require use of a scan tool to display ignition timing. The timing light is connected to the ignition circuit and used to illuminate the timing marks on the engine's crankshaft pulley or flywheel, with the engine running. The apparent position of the marks, frozen by the stroboscopic effect, indicates the current timing of the spark in relation to piston position. A reference pointer is attached to the flywheel housing or other fixed point, and an engraved scale gives the offset between the spark time and the top dead centre position of the piston in the cylinder. The distributor can be rotated slightly until the reference pointer aligns with the specified point on the timing scale. Fuel-injected engines, or engines with microprocessor controls may require specia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LC Circuit
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, is an electric circuit consisting of an inductor, represented by the letter L, and a capacitor, represented by the letter C, connected together. The circuit can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit's resonant frequency. LC circuits are used either for generating signals at a particular frequency, or picking out a signal at a particular frequency from a more complex signal; this function is called a bandpass filter. They are key components in many electronic devices, particularly radio equipment, used in circuits such as oscillators, filters, tuners and frequency mixers. An LC circuit is an idealized model since it assumes there is no dissipation of energy due to resistance. Any practical implementation of an LC circuit will always include loss resulting from small but non-zero resistance within the components and connect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Series And Parallel Circuits
Two-terminal components and electrical networks can be connected in series or parallel. The resulting electrical network will have two terminals, and itself can participate in a series or parallel topology. Whether a two-terminal "object" is an electrical component (e.g. a resistor) or an electrical network (e.g. resistors in series) is a matter of perspective. This article will use "component" to refer to a two-terminal "object" that participates in the series/parallel networks. Components connected in series are connected along a single "electrical path", and each component has the same electric current through it, equal to the current through the network. The voltage across the network is equal to the sum of the voltages across each component. Components connected in parallel are connected along multiple paths, and each component has the same voltage across it, equal to the voltage across the network. The current through the network is equal to the sum of the currents thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
