ballast
unit inserted between the power supply and at least one discharge lamp that by means of inductance, capacitance or resistance, single or in combination, serves mainly to limit the current of the discharge lamp(s) to the required value
Note 1 to entry: A ballast can also include means for transforming from the power supply voltage and arrangements which help to provide starting voltage and preheating current, to prevent cold starting, to reduce stroboscopic effect, to correct the power factor and to suppress radio interference.
Note 2 to entry: This entry was numbered 845-08-34 in IEC 60050-845:1987.
Note 3 to entry: This entry was numbered 17-73 in CIE S 017:2011.