Electronic Ballast with CELMA energy efficiency index A2 BAT/A2. It offers a large temperature range, devices can operate either 1 or 2 lamps, intelligent voltage guard, constant luminous flux irrespective of fluctuations in mains voltage, for luminaires of protection class I and protection class II. It also offers automatic start after replacement of defective lamps and safety shutdown of defective lamps and at end of lamp life.