A cold cathode fluorescent lamp (CCFL) is a type gas-discharge lamp similar to linear fluorescent or compact fluorescent lampscompact fluorescent lampsEnergy efficiency The luminous efficacy of a typical CFL is 50–70 lumens per watt (lm/W) and that of a typical incandescent lamp is 10–17 lm/W. Compared to a theoretical 100%-efficient lamp (680 lm/W), CFL lamps have lighting efficiency ranges of 7–10%, versus 1.5–2.5% for incandescents.https://en.wikipedia.org › wiki › Compact_fluorescent_lampCompact fluorescent lamp - Wikipedia. CCFLs are used in a number of different specialty applications, such as cold-weather lighting, display back lighting, and signage.
Which lamp is a cold cathode lamp?
cathode fluorescent lamp
What is hot cathode fluorescent lamp?
Because the cathodes are heated to approximately 900 degrees Fahrenheit, this type of fluorescent light bulb is referred to as hot cathode fluorescent. A standard CFL is a hot cathode light bulb. ... As a result, the voltage of CCFL light bulbs is higher than CFLs, and the CCFL's electrical current is lower.
Is led cold cathode?
Sure, LEDs and CFLs trump incandescent bulbs by a mile. But apparently, an even greener lighting alternative exists, and it's called Cold Cathode Lighting. Cold Cathode Lighting is a tubular light that derives its light by passing an electrical current through a gas or vapor.Sep 25, 2012
How do fluorescent lamps work?
A fluorescent lamp generates light from collisions in a hot gas ('plasma') of free accelerated electrons with atoms– typically mercury – in which electrons are bumped up to higher energy levels and then fall back while emitting at two UV emission lines (254 nm and 185 nm).
What is the meaning of cold cathode?
Definition of cold cathode : a cathode in an electron tube or fluorescent lamp that is unheated and that emits electrons when bombarded by ions or subjected to light, infrared, or ultraviolet rays cold-cathode tube.
What is the purpose of the cathode in a fluorescent tube?
The cathode is made of a coiled tungsten filament. When the light bulb is turned on, the cathodes are heated to extremely hot temperatures, which causes them to emit, or release, electrons, the negatively charged particles of an atom.
How do fluorescent tubes work physics?
A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow.
What is cold cathode emission?
Definition. A cold cathode is a cathode that is not electrically heated by a filament. A cathode may be considered "cold" if it emits more electrons than can be supplied by thermionic emission alone. It is used in gas-discharge lamps, such as neon lamps, discharge tubes, and some types of vacuum tube.
What is cold cathode UV?
Cold Cathode Fluorescent Lamp (CCFL) and UV Lights are light sources that use a mercury vapor to emit UV light that causes a phosphor coating to emit light (CCFL) and other light sources that provide wavelengths in the Ultraviolet frequency range (750 THz to 30,000 THz).