Abstract: Phosphor from the class of the oxynitridosilicates, having a cation M which is doped with divalent europium, and having the empirical formula M(1-c)Si2O2N2:Dc, where M=Sr or M=Sr(1-x-y)BayCax with x+y<0.5, the oxynitridosilicate completely or predominantly comprising the high-temperature-stable modification HT.

Abstract: The invention relates to a circuit arrangement for operating electric lamps, the circuit arrangement having an inverter for generating a medium or high-frequency supply voltage for one or more lamps (21) and a starting circuit for the inverter, and also a device for deactivating the starting circuit, the starting circuit comprising a voltage-dependent switching element (34) and a capacitor (33), and the device for deactivating the starting circuit comprising a switching means (35) whose switching path is arranged in parallel with the capacitor (33) of the starting circuit. According to the invention, the device for deactivating the starting circuit has a threshold switch (39) for controlling the switching means (35).

Abstract: An electronic ballast for discharge lamps with electrode filaments. The ballast contains a frequency-selective device, which suppresses an auxiliary heating current in the electrode filaments during operation of the lamp. Heating of the electrode filaments is possible only within a narrow frequency band.