Electrical ballast is a device intended to control the amount of current flowing in an electric circuit. Ballasts vary greatly in complexity. They can be as simple as a series resistor as commonly used with small neon lamps. For high-power installations, too much energy would be wasted in resistive ballast, so alternatives are used that depend upon the reactance of inductors, capacitors, or both. Finally, ballasts can be as complex as the computerized, remote-controlled electronic ballasts used with fluorescent lamps.