ELECTRICAL ENCYCLOPEDIA

What is a Compact Fluorescent Lamp?   A compact fluorescent lamp (CFL), also called compact fluorescent light, energy-saving light, and compact fluorescent tube, is a fluorescent lamp designed to replace an incandescent lamp; some types fit into light fixtures formerly used for incandescent lamps. The lamps use a tube which is curved or folded to fit into the space of an incandescent bulb, and a compact electronic ballast in the base of the lamp. continue.. Basic Facts of a Compact Fluorescent Lamp   A compact fluorescent lamp will initially cost more than an incandescent bulb, but because it lasts longer and costs so much less to run, it will prove to be a better bargain over time.  Just keep in mind that light bulbs cost much more to run than to buy in the first place. continue.. History of Compact Fluorescent Lamp   Edmund Germer, Friedrich Meyer, and Hans Spanner then patented a high pressure vapor lamp in 1927. George Inman later teamed with Gen...

What is an Optical Fiber?   An optical fiber (or optical fibre) is a flexible, transparent fiber made of a pure glass (silica) not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber.[1] The field of applied science and engineering concerned with the design and application of optical fibers is known as fiber optics. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communication. Fibers are used instead of metal wires because signals travel along them with less loss and are also immune to electromagnetic interference. continue.. History of Fiber Optics?   Optical communication systems date back two centuries, to the "optical telegraph" that French engineer Claude Chappe invented in the 1790s. His system was a series of semaphores mounted on towers, where human operators ...

What is AMR?   Automatic meter reading, or AMR, is the technology of automatically collecting consumption, diagnostic, and status data from water meter or energy metering devices (gas, electric) and transferring that data to a central database for billing, troubleshooting, and analyzing. This technology mainly saves utility providers the expense of periodic trips to each physical location to read a meter. Another advantage is that billing can be based on near real-time consumption rather than on estimates based on past or predicted consumption. This timely information coupled with analysis can help both utility providers and customers better control the use and production of electric energy, gas usage, or water consumption.  continue.. About AMR Technology   The Automated Meter Reading (AMR) system consists of small, low-power radio transmitters connected to individual water meters that send daily readings to a network of rooftop receivers throughout the city.  I...

What is Lighting a.k.a Illumination?   Lighting or illumination is the deliberate application of light to achieve some practical or aesthetic effect. Lighting includes the use of both artificial light sources such as lamps and light fixtures, as well as natural illumination by capturing daylight. Daylighting (using windows, skylights, or light shelves) is often used as the main source of light during daytime in buildings. This can save energy compared with artificial lighting, which represents a major component of energy consumption in buildings. Without proper design, energy can be wasted by using too much light, or using out-dated technology. Proper lighting can enhance task performance, improve the appearance of an area, and have positive psychological effects on occupants. One of the core tenets of proper lighting is uniform illumination, which is required in many applications such as projection displays, LCD backlights, medical lighting, microscopy, solid-state lighting, and ...

What is an Arc Flash?   Arc flash temperatures can reach or exceed 35,000 F at the arc terminals. The massive energy released in the fault rapidly vaporizes the metal conductors involved, blasting molten metal and expanding plasma outward with extreme force. A typical arc flash incident can be inconsequential but could conceivably easily produce a more severe explosion (see calculation below). The result of the violent event can cause destruction of equipment involved, fire, and injury not only to the worker but also to nearby people. continue.. Where does Arc Flash come from?   Arc Flash is the result of a rapid release of energy due to an arcing fault between a phase bus bar and another phase bus bar, neutral or a ground. During an arc fault the air is the conductor. Arc faults are generally limited to systems where the bus voltage is in excess of 120 volts. Lower voltage levels normally will not sustain an arc. An arc fault is similar to the arc obtained during electri...

What is the basic definition of a Surge?   A surge is a sudden gust of something or a very sudden and dramatic increase. (noun). To surge is to quickly and suddenly move as part of a crowd, to increase rapidly and suddenly, or to cause someone to feel sudden and powerful emotions. (verb) continue.. What is a Surge Protector?   A surge protector (or surge suppressor) is an appliance designed to protect electrical devices from voltage spikes. A surge protector attempts to limit the voltage supplied to an electric device by either blocking or by shorting to ground any unwanted voltages above a safe threshold. This article primarily discusses specifications and components relevant to the type of protector that diverts (shorts) a voltage spike to ground; however, there is some coverage of other methods. continue.. How does a Surge Protector Works?   When you put together a computer system, one piece of standard equipment you'll probably buy is a surge protector. Most desi...

How is a Plane Protected from Lightning?   Most aircraft do not fly into lightning storms, or fly through storms or areas where lightning is likely to be present. What we see as lightning is really a massive flood of electrons seeking equilibrium, either from cloud-cloud or from cloud-ground. In both cases, huge amounts of electric charge build up at the edges of the cloud. The electricity finds it's way from one place to the other via what's called a "step leader". continue.. Lightning Strike Protection for Carbon Fiber Aircraft   Lightning strikes on transport aircraft happen periodically depending on many parameters including atmospheric conditions and operational characteristics of the airplane. Most recent nacelle fleet history, circa 2002-2005, has shown that lightning strike damage has occurred more frequently on shorter mission commercial aircraft equipped with composite panels than prior configurations of nacelle panels. It should be...

What is a Ground (electricity)?   Electrical circuits may be connected to ground (earth) for several reasons. In mains powered equipment, exposed metal parts are connected to ground to prevent contact with a dangerous voltage if electrical insulation fails. Connections to ground limit the build-up of static electricity when handling flammable products or when repairing electronic devices. In some telegraph and power transmission circuits, the earth itself can be used as one conductor of the circuit, saving the cost of installing a separate return conductor. continue.. How Electrical Grounding Works   Grounding, Electrical, the connecting of electrical equipment and wiring systems to the earth by a wire or other conductor The primary purpose of grounding is to reduce the risk of serious electric shock from current leaking into uninsulated metal parts of an appliance, power tool, or other electrical device. In a properly grounded system, such leaking current (called fault cu...

What is a Wire?   A wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Standard sizes are determined by various wire gauges. The term wire is also used more loosely to refer to a bundle of such strands, as in 'multistranded wire', which is more correctly termed a wire rope in mechanics, or a cable in electricity. continue.. FAQs on Wire Types and Sizes   Most electrical wire is covered in a rubber or plastic coating called insulation. What is the purpose of having this ïnsulation" covering the metal wire? In the early days of electrical wiring, wires used to be insulated with cotton. This is no longer accepted practice. Explain why. Electrical wire is often rated according to its cross-sectional diameter by a gauge scale. Which is the larger-diameter wire size, 14 ...

What is a Ferrite Bead?   A ferrite bead is a passive electric component used to suppress high frequency noise in electronic circuits. It is a specific type of electronic choke. Ferrite beads employ the mechanism of high dissipation of high frequency currents in a ferrite to build high frequency noise suppression devices. Ferrite beads may also be called ferrite blocks, ferrite cores, ferrite rings, ferrite EMI filters, ferrite chokes or ferrous beads.. continue.. What are ferrite beads made for?   A ferrite bead is simply a hollow bead or cylinder made of ferrite, which is a semi-magnetic substance made from iron oxide (rust) alloyed with other metals. It slips over the cable when the cable is made, or it can be snapped around the cable in two pieces after the cable is made. The bead is encased in plastic -- if you cut the plastic, all that you would find inside is a black metal cylinder.. continue.. Disadvantages of Ferrite   Ferrites are substances derived from a...