Ballast

[eric1973]

What is the purpose of a ballast? Save energy? Step up/down the voltage?

 

[rattus]

What is the purpose of a ballast? Save energy? Step up/down the voltage?

The ballast is an inductor which limits the current in fluorescent lamps. Inductors do this more efficiently than do resistors. The ballast also provides an "inductive kick" to help ionize the mercury vapor in the fluorescent tube.

 

[augie47]

ballasts

ballasts

the term can mean different things.
a good link


http://en.wikipedia.org/wiki/Electrical_ballast

 

[LarryFine]

Even the 100-150k resistor used withn an NE-2 (neon bulb) is considered a ballast. It limits bulb current because its voltage drop varies with the current. If the current attempts to rise, more voltage drops in the resistor, bringing the current back down.