Patent ID: 6144174
Filing Date: 2000-11-07
Classification: H02M,H03K,H05B,Y10S

Abstract:
A control device for a low-pressure fluorescent lamp comprising a first change-over switch circuit and a second change-over switch circuit series-connected between a high voltage and the ground, a first change-over switch circuit comprising a first power transistor, the second change-over switch circuit comprising a second power transistor, an inductor being series-connected with the low-pressure fluorescent lamp and with a capacitor between the midpoint of the two change-over switch circuits and the ground,wherein the first change-over switch circuit comprises:a circuit for measuring the period during which the second power transistor is on to measure a first period; anda switching-on circuit to turn the first power transistor on during a second period that is consecutive and equal to the first period.