Purpose Of Capacitor In Fluorescent Lamp

Fluorescent lamps form an inductive load on the ac mains supply.

Purpose of capacitor in fluorescent lamp.

The process that occurs inside a fluorescent light involves molecules of mercury gas being heated by electricity and made more conductive. The capacitor is in most common fluorescent lamp circuits is for power factor correction. Since there is a coil in the ballast the capacitor is used to bring the power factor back towards unity. As a result large installations of such lamps suffer a poor power factor and resultant voltage drop.

A capacitor is used to improve the power factor of the lamp more detailsto prevent the lamp from taking too much current a fluorescent lamp has to have a choke which has magnetic inductance. A fluorescent light does not have the usual glowing filament of an incandescent bulb but instead contains a mercury vapor that gives off ultraviolet light when ionized. An electrical ballast is a device placed in series with a load to limit the amount of current in an electrical circuit. A familiar and widely used example is the inductive ballast used in fluorescent lamps to limit the current through the tube which would otherwise rise to a destructive level due to the negative differential resistance of the tube s voltage current characteristic.

Fluorescent starters are used in several types of fluorescent lights. Question is the function of capacitor across the supply to the fluorescent tube is primari ly to options are a stabilize the arc b reduce the starting current c improve the supply power factor d reduce the noise e leave your comments or download question paper. The ultraviolet light makes particles that coat the inside of the tube and these particles glow or fluoresce see how fluorescent lamps work for details. Without a ballast to control this there would be too much current for the light to take and it would burn out and possibly even catch fire.