Electronic starting device for starting fluorescent lamps in radio-frequency operation

摘要

So that the fluorescent lamp 12 which is operated at radio frequency starts successfully and without flickering over a wide temperature range, a circuit arrangement which consists of one or more individual capacitances 19, 20 in series with a parallel circuit consisting of a temperature-dependent resistor having a negative temperature coefficient 21, and a non-reactive resistor 22, are arranged in series with the heating electrodes 10, 11. The characteristic of the parallel circuit consisting of PTC thermistor 21 and non-reactive resistor 22 counteracts the characteristic of the heating electrodes 10, 11 (positive temperature coefficient) and causes a steady rise of pre-heating current and starting voltage until the lamp 12 starts. The slope of the rise adjusts itself as a function of the ambient temperature to the value which is necessary for a reliable and lamp-saving starting process. <IMAGE>