Search results
Results from the WOW.Com Content Network
Flicker at power frequency is more noticeable in the peripheral vision than it is when viewed directly. Near the end of life, fluorescent lamps can start flickering at a frequency lower than the power frequency. This is due to instability in the negative resistance of arc discharge, [74] which can be from a bad lamp or ballast or poor connection.
In visual perception, flicker is a human-visible change in luminance of an illuminated surface or light source which can be due to fluctuations of the light source itself, or due to external causes such as due to rapid fluctuations in the voltage of the power supply (power-line flicker) or incompatibility with an external dimmer.
The requirements of a flicker measurement equipment are defined in the international electro-technical standard IEC 61000-4-15. [2]A flickermeter is composed of several function blocks which simulate a 230 V/60 W or a 120 V/60 W incandescent lamp (reference lamp) and the human perception system (eye-brain model).
The flicker index, used for measuring perceptible light modulation, has a range from 0.00 to 1.00, with 0 indicating the lowest possibility of flickering and 1 indicating the highest. Lamps operated on magnetic ballasts have a flicker index between 0.04 and 0.07 while digital ballasts have a flicker index of below 0.01.
A flicker light bulb, flicker flame light bulb or flicker glow lamp is a gas-discharge lamp which produces light by ionizing a gas, usually neon mixed with helium and a small amount of nitrogen gas, by an electric current passing through two flame shaped electrode screens coated with partially decomposed barium azide. The ionized gas moves ...
A General Electric NE-34 glow lamp, manufactured circa 1930. Neon was discovered in 1898 by William Ramsay and Morris Travers.The characteristic, brilliant red color that is emitted by gaseous neon when excited electrically was noted immediately; Travers later wrote, "the blaze of crimson light from the tube told its own story and was a sight to dwell upon and never forget."
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Flicker noise is a type of electronic noise with a 1/f power spectral density. It is therefore often referred to as 1/ f noise or pink noise , though these terms have wider definitions. It occurs in almost all electronic devices and can show up with a variety of other effects, such as impurities in a conductive channel, generation and ...