Ballast for connection of a discharge lamp

摘要

Discharge lamps are frequently connected to the AC voltage mains power supply via an invertor and a rectifier, the invertor operating at a frequency of at least 10 kHz. In consequence, the inductance which is required for current limiting can be kept low and a high light yield can be achieved at the same time. However, in this case, the waveform of the current taken from the mains power supply is highly non-sinusoidal. In order to avoid this, the current extraction has already been controlled using a two-point regulator to which the mains power supply half-cycle is supplied as the required value and the lamp current as the actual value. The modulation of the lamp voltage which occurs in this case with the mains supply voltage is avoided as a result of the invention. <IMAGE>