Equipment used with discharge lamps for stabilizing the discharge.
Note 1: A ballast may be resistive, inductive or capacitive, or a combination of these.
Note 2: The ballast may also be used, either alone or in combination with a starter, to light the lamp. The starter may be incorporated in the ballast.
Reference: CContrastCelsius (previously Centigrade)Capacitance.Icharge currentIntensity.EIlluminanceEnergy.
Please note that this is the term as it stands in the original IALAInternational Association of Marine Aids to Navigation and Lighthouse Authorities - AISM Dictionary edition (1970-1989)