Other CFL Technologies
Another type of fluorescent lamp is the electrodeless lamp, known as magnetic induction lamp, radiofluorescent lamp or fluorescent induction lamp. These lamps have no wire conductors penetrating their envelopes, and instead excite mercury vapour using a radio-frequency oscillator. As of 2011 this type of light source was struggling with high cost of production, stability of the products produced by domestic manufacturers in China, establishing an internationally recognized standard and problems with EMC and RFI . Furthermore, induction lighting is excluded from Energy Star standard for 2007 by the EPA.
The cold-cathode fluorescent lamp (CCFL) is a newer form of CFL. CCFLs use electrodes without a filament. The voltage of CCFLs is about 5 times higher than CFLs, and the current is about 10 times lower. CCFLs have a diameter of about 3 millimeters. CCFLs were initially used for document scanners and also for back-lighting LCD displays, and later manufactured for use as lamps. The efficacy (lumens per watt) is about half that of CFLs. Their advantages are that they are instant-on, like incandescents, they are compatible with timers, photocells, and dimmers, and they have a long life of approximately 50,000 hours. CCFLs are an effective and efficient replacement for lighting that is turned on and off frequently with little extended use (for example, in a bathroom or closet).
A few manufacturers make CFL bulbs with mogul Edison screw bases intended to replace 250- and 400-watt metal halide lamps, claiming a 50% energy reduction; these lamps require rewiring of the lamp fixtures to bypass the lamp ballast.
Read more about this topic: Compact Fluorescent Lamp