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Fluorescent light fixtures cannot be connected to dimmer switches intended for incandescent lamps. Two effects are responsible for this: the waveform of the voltage emitted by a standard phase-control dimmer interacts badly with many ballasts, and it becomes difficult to sustain an arc in the fluorescent tube at low power levels.
Cars in the US only have red tail lights, and no blue lights; a vehicle displaying a red (forward-facing) light (flashing or not) coming towards a driver, or from behind the driver (in rearview mirror) indicates that an official emergency vehicle is coming, requiring the driver to yield, pull off to the side of the road, or otherwise get out of ...
A wide variety of special light fixtures are created for use in the automotive lighting industry, aerospace, marine and medicine sectors. [2] [3] Portable light fixtures are often called lamps, as in table lamp or desk lamp. In technical terminology, the lamp is the light source, which, in casual terminology, is called the light bulb.
For example, a PAR16 lamp is approximately 2 inches or 50.8 mm in diameter. [1] The size of rectangular PAR lamps is expressed as the letters REC followed by the reflector's mouth height, the letter "X", and the reflector's mouth width—with both dimensions in millimeters. For example, REC142X200 lamps are 142 high and 200 mm wide. [2] [3]
Left to right: MR16 with GU10 base, MR16 with GU5.3 base, MR11 with GU4 or GZ4 base Line drawing of an LED MR16 lamp, with a heatsink rather than a reflector. A multifaceted reflector (often abbreviated MR) light bulb is a reflector housing format for halogen as well as some LED and fluorescent lamps.
Fluorescent lighting is more energy-efficient than incandescent lighting elements. However, the uneven spectrum of traditional fluorescent lamps may cause certain colors to appear different from when illuminated by incandescent light or daylight. The mercury vapor emission spectrum is dominated by a short-wave UV line at 254 nm (which provides ...
Luminous flux (in lumens) is a measure of the total amount of light a lamp puts out. The luminous intensity (in candelas) is a measure of how bright the beam in a particular direction is. If a lamp has a 1 lumen bulb and the optics of the lamp are set up to focus the light evenly into a 1 steradian beam, then the beam would have a luminous ...
High-pressure lamps have a discharge that takes place in gas under slightly less to greater than atmospheric pressure. For example, a high pressure sodium lamp has an arc tube under 100 to 200 torr pressure, about 14% to 28% of atmospheric pressure; some automotive HID headlamps have up to 50 bar or fifty times atmospheric pressure.