Electrical components are found everywhere in electronic products to assist their efficient running. Switching power supplies convert unregulated power from batteries or other sources to a regulated voltage required to operate electronic devices such as computers, servers, audio and video products. Voltage regulators, such as DC to DC converters, are used to provide stable voltage sources for electronic systems. Power inverters serve to invert a DC voltage into a corresponding AC voltage by turning on and off the DC voltage. An uninterruptible power supply (UPS) is a type of power supply used as a backup power supply for a large number of electronic devices, such as cordless telephones, desktop computers, baby monitors, alarm systems, video surveillance systems, and answering machine. Power amplifiers are used to increase the power level of a signal. Many communications systems, particularly wireless communication systems, use power amplifiers to amplify the signal before it is transmitted. Power transformers provide rated voltage and current to electric and electronic devices while isolating those devices from the AC current mains. An electical switch is a mechanical device which makes or breaks an electrical contact. Switches ordinarily are used to control the flow of electrical current to a variety of devices which operate by electricity. Relays are used to control a high voltage circuit with a low voltage signal, to control a high current circuit with a low current signal, to perform time delay functions, to perform logic functions, and to provide transient surge protection. Circuit breakers protect electrical circuitry from damage due to an overcurrent condition, such as an overload condition or a relatively high level short circuit or fault condition.
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Friday, 02 February 2007 |
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A ground fault circuit interrupter (GFCI) is a device that is intended to reduce the chance of accidental electrocution by interrupting the power line, when the difference in current is greater than a predetermined level. The ground fault condition results when a person comes into contact with the line side of the AC load and an earth ground at the same time, a situation which can result in serious injury. The GFCI device is operable to enter a de-energized state to isolate an AC load connected to the load side terminals from the line side terminals upon detecting a ground fault condition. GFCIs cut off the supply of electric current to a "hot" surface immediately upon flow of electric current to ground through other than the normal return path of the circuit in which the electrical appliance is connected. |
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Thursday, 01 February 2007 |
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Circuit breakers are used to protect electrical circuitry from damage due to an overcurrent condition, such as an overload condition or a relatively high level short circuit or fault condition. Circuit breakers used in residential and light commercial applications are commonly referred to as miniature circuit breakers because of their limited size. A miniature circuit breaker has a thermal-magnetic trip device that opens the circuit breaker contacts in response to persistent current in excess of a predetermined rated current and stops the flow of electrical current through the circuit breaker to the protected electrical equipment. Some miniature circuit breakers include ground fault interruption (GFI) circuitry to protect against ground faults which occur when current flows from a hot conductor to ground. |
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Monday, 15 January 2007 |
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Electric circuit breakers are used to protect branch circuits in residential, commercial and industrial buildings against overload and fault conditions. The circuit breaker can be classified into an oil circuit breaker using oil, a gas circuit breaker, an air circuit breaker using the air, a magnetic blow-out circuit breaker using magnetism, and a vacuum breaker using vacuum in accordance with used arc extinguishing medium. Circuit breaker and other circuit interrupters are often constructed with contacts and blades to form the electrical disconnect. A circuit breaker basically consists of a main contact at system voltage, insulation between main contact and ground potential (porcelain, oil, gas), operating and supervisory devices, and an insulated link between operating device and main contact. |
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Monday, 08 January 2007 |
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Overload relays are specialized circuit breakers used with industrial equipment such as motors to protect the equipment from damages caused by overload or electrical faults. Overload relays are employed to protect such expensive machinery from damage due to overheating resulting from excessive current flow through the motors. Overload relays are used in conjunction with an electromechanical contactor. Various devices are utilized to sense a current flow and to trip a switch or the like when the current level exceeds the predetermined value. A thermal overload relay uses a bimetal plate for detecting an overload. Most overload relays include solid state analog or digital circuitry capable of interrupting power to a protected device in the event of overload, phase loss, ground fault or other failure. |
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Tuesday, 02 January 2007 |
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Dimmer switches are used for varying the electric power applied to an electric load such as an electric light. Dimming control systems utilizing self contained, interchangeable dimmer modules are commonly used in theater, television, and architectural lighting applications. Dimmer switches are well known devices for varying the light intensity of an illuminating device usually between a fully on state and a fully off state. Rather than use a variable resistor type rheostat which wastes power and generates heat at low illumination levels, modern dimmer switches employ phase regulation. A phase control circuit renders a solid state switch conductive at a point during a half cycle of the sinusoid. Switching operations are performed by the SCRs in a phase angle dimmer at a low frequency. |
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Saturday, 16 December 2006 |
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An electrical fuse is a current interrupting device which protects a circuit by fusing open its current-responsive element when an overcurrent or short-circuit current passes through it. Electrical fuses are metal fusible links which carry the current in the circuit being protected. These fuse links melt or vaporize at a given current level to open the circuit being protected. The fuses must be replaced after their operation. Circuit breakers may also be used to protect electrical circuits, but they are large and expensive. High voltage current-limiting fuses consist of a fusible element, a core to support this element, filler for enhancing the interruption of fault current at high voltages, and a housing. A fuse holder includes a fuse carrier or fuse-carrier unit mounted within a receptacle or receptacle unit. |
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Sunday, 10 December 2006 |
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Insulators are used to prevent the loss of electric charge or current from conductors in power transmission lines. Electrical insulators are electrically insulating components in various electric circuits and electrical installations. Insulators for high voltage electrical transmission lines may take many forms. A typical insulator is constructed from a material with a high resistance to electric current so that the electric current does not substantially flow therethrough. Insulators have been made of ceramic or porcelain materials. Ceramic insulators are brittle and easily chipped or broken. In recent years, composite insulators have become extremely popular. Composite insulators exhibit many advantages over traditional ceramic and glass insulators, such as lighter weight, lower material and installation costs. |
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Sunday, 03 December 2006 |
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Circuit breakers provide protection for electrical systems from electrical fault conditions such as current overloads and short circuits. A circuit breaker interrupts a fault current flowing at a time of electric power system accident and protects the electric power system. A vacuum circuit breaker turns an electric current on and off by using movable and fixed electrodes disposed in a vacuum container. Vacuum circuit breakers each contain an electrode structure composed of a pair of a fixed electrode and a movable electrode. The fixed and movable electrodes each comprise an arc electrode, an arc electrode support member for supporting the arc electrode, a coil electrode contiguous to the arc electrode support member, and an electrode rod provided at an end portion of the coil electrode. |
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Sunday, 19 November 2006 |
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Solar energy can be collected and concentrated, and then converted into electrical energy. A solar power generation system comprises a solar cell array which converts sunlight to electrical energy. Solar panels include solar cells which are semiconductor materials that achieve the conversion of light energy into electrical current. Some solar power systems use parabolic trough, planar mirror array and parabolic reflector dish systems to collect and concentrate solar energy to generate electrical power. A solar power system has a power converter that converts incident light energy into power. The output power of the solar cell increases with the intensity of the incident light. The absorbed optical energy provides a source of thermal energy to operate a power conversion cycle or heat engine. |
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Sunday, 12 November 2006 |
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A basic component incorporated in a computer is a power supply unit that functions to receive alternating current (AC) electrical power from an external source and transform the received power to a relatively low direct current (DC) voltage that may be fed to various electronic components. The switching power supply transforms the local electrical power and provides the computer system with a proper operational voltage. The switching power supply also distributes the electrical power to sub systems of the computer requiring different voltage levels. The electrical power used in a computer system is a direct current with a voltage usually under 12 Volts. A computer is generally provided with input/output (I/O) ports including a power supply conductor for powering peripheral devices connected to such ports. |
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Thursday, 02 November 2006 |
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A direct current (DC) voltage can be converted to another DC voltage via a DC-to-DC converter. A DC-DC converter is used to convert a DC voltage supplied from a power source to a desired voltage that is different from the power source voltage. DC-DC converters are widely utilized as an efficient means to convert one DC voltage to another desired DC voltage in electronic applications that require a stable power supply potential. DC-DC voltage converters having switched capacitor arrays usually have fairly high conversion efficiency and can be implemented in integrated circuit form. Due to their ability to receive low input voltages and consume low power, DC-DC converters have been used in all types of electronic products. Portable electronic equipment uses a battery as a power source. |
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Saturday, 21 October 2006 |
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Uninterruptible power supply (UPS) systems operate in conjunction with a main power source to ensure a continuous supply of energy to critical AC loads. An uninterruptible power supply uses a battery backup as a secondary or reserve power source which is activated to supply power to the load upon total failure of the commercial power or significant degradation of the primary power source. Uninterruptible power supply systems are used in a wide variety of applications, such as for providing reliable and regulated AC power to computer systems, telecommunications switching equipment and cable television transmission equipment. An uninterruptible power supply generally comprises a rectifier, inverter, battery charger, DC battery, input filter/surge protector, controller, and other components. |
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Friday, 13 October 2006 |
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An electric motor is a rotary machine which converts electrical energy to mechanical energy. An electric motor uses current power to provide assist torque and drive machines. An electric motor comprises a rotor having a field system and a stator having armature coils and is adapted to control a rotational speed by controlling a drive current flowing through the armature coils by means of a controller. Electronic control circuits are used in a wide variety of devices that use electric motors. The control circuit allows a user or system containing the electric motor to adjust various parameters of the power being supplied to the electric motor. There're various types of motors, such as induction motors, brushed DC motors, stepping motors, torque motors, permanent magnet motors, and brushless motors. |
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Tuesday, 03 October 2006 |
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Surge protectors protect voltage sensitive equipment connected to electrical lines by discharging high voltage signals or current surges to ground before the high voltage signal can damage the equipment. Surge protection devices protect electronic equipment from being damaged by large variations in the current and voltage across power and transmission lines resulting from lightning strikes, transients, noise, incorrect connections, and other abnormal conditions or malfunctions. A prolonged overvoltage surge may cause a surge protection device to overheat, thus presenting a fire hazard. Various types of surge protectors are used to protect electrical equipment from electrical power surges. Surge protectors are divided into primary type surge protectors and secondary type surge protectors. |
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Friday, 15 September 2006 |
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A relay is an electrical switch that opens and closes automatically under control of another electrical circuit. Electromechanical relays are electromagnetic devices in which current flowing through a coil actuates a pair of electrical contacts. Electromechanical switching devices use solenoid driven means to transfer electromechanical contacts to apply a source voltage to a load. A solid state relay provides isolation between a control circuit and a switched circuit and may replace an electromechanical device such as a reed relay. Solid state relays have all solid state components, and do not require any moving parts. Solid state relays have advantages over electromechanical relays, such as increased lifetime, decreased electrical noise, compatibility with digital circuitry, and resistance to corrosion. |
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Tuesday, 05 September 2006 |
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Electrical generators transform mechanical energy into electrical energy. A generator set includes an engine driven by a fuel such as gasoline, and a rotating shaft driven by the engine. Electric power plants include hydroelectric power plants, thermal power plants, and nuclear power plants. Generated electricity is delivered through power transmission lines and potential transformers. Synchronous power generators have a magnetic rotor that is surrounded by a stationary stator having conductive windings. A turbine generator generates electric power by converting mechanical energy into electrical energy. Hydroelectric power generation is one of the most inexpensive and cleanest methods for generating large amounts of electric power. Wind power generation produces electric power utilizing natural wind. |
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Wednesday, 30 August 2006 |
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Power adapters are commonly used to supply power to electrical and electronic devices, such as laptop and notebook computers, personal digital assistants (PDA), cellular phones, digital cameras, audio recorders, compact disc (CD) players, MP3 players, portable digital video disc (DVD) players, electric toothbrushes, shavers, hand-held vacuum cleaners, radios, and telephone sets. AC adapters are used for various purposes such as the recharging of mobile phones and the converting of AC voltage into a desired AC voltage or a DC voltage. Portable electronics devices have a port for connecting to the adapter, and the port has a plurality of contacts. A power adapter is usually one of the accessories transported along with a portable electronic device. |
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Friday, 18 August 2006 |
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Transformers are utilized to step electrical voltages up or down, to couple signal energy from one stage to another, and to match the impedances of interconnected electrical or electronic components. Transformers transfer electric energy from one circuit to another circuit through magnetic induction. A transformer ordinarily consists of wire windings around a ferromagnetic core. There are two types of transformers used to convey electricity from a transmission system to a distribution system. Power transformers provide rated voltage and current to electric and electronic devices while isolating those devices from the AC current mains. Distribution transformers are installed in the distribution network to lower the voltage to levels conveyed to commercial buildings, households, and other end users. |
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Electrical Components
