摘要 |
For driving one or more gas discharge lamps (2) to conduct or to block at any time and at the same time, a rectangular high voltage is generated from a high DC voltage, an alternating voltage with respect to a reference voltage (V-) is generated from the rectangular voltage, the alternating voltage is supplied to first electrodes (4) of the lamps, second electrodes (6) of the lamps are selectively connected to the reference voltage, a current flowing through each lamp is stabilized (26), the alternating voltage is filtered to provide a filtered voltage, a property of the filtered voltage is measured to provide a control signal, the control signal is used to control the frequency of the rectangular voltage, and the filtering has a response characteristic which is substantially identical to a response characteristic provided by a lamp when conducting and means for said stabilizing of current flowing through the lamp. |