Small applianceA small domestic appliance, also known as a small electric appliance or minor appliance or simply a small appliance, small domestic or small electric, is a portable or semi-portable machine, generally used on table-tops, counter-tops or other platforms, to accomplish a household task. Examples include microwave ovens, kettles, toasters, humidifiers, food processors and coffeemakers. They contrast with major appliances (known as "white goods" in the UK), such as the refrigerators and washing machines, which cannot be easily moved and are generally placed on the floor.
Overhead lineAn overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, trolleybuses or trams. The generic term used by the International Union of Railways for the technology is overhead line. It is known variously as overhead catenary, overhead contact line (OCL), overhead contact system (OCS), overhead equipment (OHE), overhead line equipment (OLE or OHLE), overhead lines (OHL), overhead wiring (OHW), traction wire, and trolley wire.
Diode bridgeA diode bridge is a bridge rectifier circuit of four diodes that is used in the process of converting alternating current (AC) from the input terminals to direct current (DC, i.e. fixed polarity) on the output terminals. Its function is to convert the negative voltage portions of the AC waveform to positive voltage, after which a low-pass filter can be used to smooth the result into DC. When used in its most common application, for conversion of an alternating-current (AC) input into a direct-current (DC) output, it is known as a bridge rectifier.
LocomotiveA locomotive or engine is a rail transport vehicle that provides the motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, motor coach, railcar or power car; the use of these self-propelled vehicles is increasingly common for passenger trains, but rare for freight. Traditionally, locomotives pulled trains from the front. However, push-pull operation has become common, where the train may have a locomotive (or locomotives) at the front, at the rear, or at each end.
AC powerIn an electric circuit, instantaneous power is the time rate of flow of energy past a given point of the circuit. In alternating current circuits, energy storage elements such as inductors and capacitors may result in periodic reversals of the direction of energy flow. Its SI unit is the watt. The portion of instantaneous power that, averaged over a complete cycle of the AC waveform, results in net transfer of energy in one direction is known as instantaneous active power, and its time average is known as active power or real power.
High frequencyHigh frequency (HF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) between 3 and 30 megahertz (MHz). It is also known as the decameter band or decameter wave as its wavelengths range from one to ten decameters (ten to one hundred meters). Frequencies immediately below HF are denoted medium frequency (MF), while the next band of higher frequencies is known as the very high frequency (VHF) band. The HF band is a major part of the shortwave band of frequencies, so communication at these frequencies is often called shortwave radio.
Smart antennaSmart antennas (also known as adaptive array antennas, digital antenna arrays, multiple antennas and, recently, MIMO) are antenna arrays with smart signal processing algorithms used to identify spatial signal signatures such as the direction of arrival (DOA) of the signal, and use them to calculate beamforming vectors which are used to track and locate the antenna beam on the mobile/target. Smart antennas should not be confused with reconfigurable antennas, which have similar capabilities but are single element antennas and not antenna arrays.
Liquid-crystal displayA liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directly but instead use a backlight or reflector to produce images in color or monochrome. LCDs are available to display arbitrary images (as in a general-purpose computer display) or fixed images with low information content, which can be displayed or hidden: preset words, digits, and seven-segment displays (as in a digital clock) are all examples of devices with these displays.
Latency (engineering)Latency, from a general point of view, is a time delay between the cause and the effect of some physical change in the system being observed. Lag, as it is known in gaming circles, refers to the latency between the input to a simulation and the visual or auditory response, often occurring because of network delay in online games. Latency is physically a consequence of the limited velocity at which any physical interaction can propagate. The magnitude of this velocity is always less than or equal to the speed of light.
ThyristorA thyristor (θaɪˈrɪstər) is a solid-state semiconductor device with four layers of alternating P- and N-type materials used for high-power applications. It acts exclusively as a bistable switch (or a latch), conducting when the gate receives a current trigger, and continuing to conduct until the voltage across the device is reverse-biased, or until the voltage is removed (by some other means). There are two designs, differing in what triggers the conducting state.
