ELECTRICAL ENCYCLOPEDIA

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 current) is

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 gauge

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 mix of iron o

What is Wi-Fi?   Wi-Fi ( /ˈwaɪfaɪ/) or Wifi, is a mechanism for wirelessly connecting electronic devices. A device enabled with Wi-Fi, such as a personal computer, video game console, smartphone, tablet, or digital audio player, can connect to the Internet via a wireless network access point. An access point (or hotspot) has a range of about 20 meters (65 ft) indoors and a greater range outdoors. Multiple overlapping access points can cover large areas. continue.. Brief History of Wi-Fi   In the beginning-Wi-Fi would certainly not exist without a decision taken in 1985 by the Federal Communications Commission (FCC), America's telecoms regulator, to open several bands of wireless spectrum, allowing them to be used without the need for a government licence. This was an unheard-of move at the time; other than the hamradio channels, there was very little unlicensed spectrum. But the FCC, prompted by a visionary engineer on its staff, Michael Marcus, took three chunks of spectrum fr

What is Bluetooth?   Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances (using short wavelength radio transmissions in the ISM band from 2400-2480 MHz) from fixed and mobile devices, creating personal area networks (PANs) with high levels of security. Created by telecoms vendor Ericsson in 1994,[1] it was originally conceived as a wireless alternative to RS-232 data cables. It can connect several devices, overcoming problems of synchronization.  continue.. Brief History of Bluetooth   Bluetooth is a wireless technology that is built into electronic gadgets. It lets you talk and share information like music, voice, and videos wirelessly. Bluetooth technology uses radio waves just like mobile phones, television, and FM radio. The difference between those devices and Bluetooth technology is distance. Radios and television broadcast too many people over many miles. Bluetooth technology just sends information to your personal space. Thi

What is an X-RAY?   X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz) and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma rays. In many languages, X-radiation is called Röntgen radiation, after Wilhelm Conrad Röntgen, who is usually credited as its discoverer, and who had named it X-radiation to signify an unknown type of radiation. Correct spelling of X-ray(s) in the English language includes the variants x-ray(s) and X ray(s). XRAY is used as the phonetic pronunciation for the letter x. continue.. History of X-RAY   All light and radio waves belong to the electromagnetic spectrum, and are all considered different types of electromagnetic waves, including: microwaves and infrared bands whose waves are longer than those of visible light (betwe

What is Thermography?   Infrared thermography, thermal imaging, and thermal video are examples of infrared imaging science. Thermal imaging cameras detect radiation in the infrared range of the electromagnetic spectrum (roughly 9000–14,000 nanometers or 9–14 µm) and produce images of that radiation, called thermograms. Since infrared radiation is emitted by all objects above absolute zero according to the black body radiation law, thermography makes it possible to see one's environment with or without visible illumination. The amount of radiation emitted by an object increases with temperature; therefore, thermography allows one to see variations in temperature. When viewed through a thermal imaging camera, warm objects stand out well against cooler backgrounds; humans and other warm-blooded animals become easily visible against the environment, day or night. As a result, thermography is particularly useful to military and other users of surveillance cameras.. continue.. An Over