- 行业: Energy
- Number of terms: 8202
- Number of blossaries: 3
- Company Profile:
American conglomerate currently ranked by Forbes as the world's largest company. GE has multifarious business interests including power generation and financial services.
A term referring to the lamp and ballast combination, and sometimes to the entire lighting delivery system including the fixture, the optics, the particular layout and the lighting controls.
Industry:Lights & lighting
A measure of the distortion of the input current on alternating current (AC) power systems caused by higher order harmonics of the fundamental frequency (60Hz in North America). THD is expressed in percent and may refer to individual electrical loads (such as ballast) or a total electrical circuit or system in a building. ANSI C82.77 recommends THD not exceed 32% for individual commercial electronic ballasts, although some electrical utilities may require lower THDs on some systems. Excessive THDs on electrical systems can cause efficiency losses as well as overheating and deterioration of system componenets.
Industry:Lights & lighting
A measure of "electrical pressure" between two points. The higher the voltage, the more current will be pushed through a resistor connected across the points. The volt specification of an incandescent lamp is the electrical "pressure" required to drive it at its designed point. The "voltage" of a ballast (e.g. 277 V) refers to the line voltage it must be connected to.
Industry:Lights & lighting
A measurement of the electromotive force in an electrical circuit or device expressed in volts. Voltage can be thought of as being analogous to the pressure in a waterline.
Industry:Lights & lighting
Current which flows in one direction and then the other, alternately.
Industry:Lights & lighting
The process by which the human eye adjusts to a change in light level.
Industry:Lights & lighting
Also called "lighting application," it refers to the particular use the lamp is being put to. (e.g. high-bay industrial application or retail lighting application.) The term can also refer in a general way to "application engineering" which deals with specific paramters and usage of light sources. (e.g. how to do a lighting layout, where to place fixtures and so on.)
Industry:Lights & lighting
This field designates the type of gas or vacuum filling a volume or chamber of the lamp. This chamber might contain a filament or it might refer to the bulb which contains the arc tube.
Industry:Lights & lighting
Device in ballast that stores electrical energy. Often used for power factor correction and lamp regulation.
Industry:Lights & lighting
Metal filaments that emit electrons in a fluorescent lamp. Negatively charged free electrons emitted by the cathode are attracted to the positive electrode (anode), creating an electric current between the electrodes.
Industry:Lights & lighting
