Abstract: Bi-state power operation of an HID lamp system. A power mode control selection determined where a high power mode and a low power mode are selectable. A modulation is determined to generate a driving signal based on the determined power mode control selection. A driving signal is generated based on the determined modulation. The generated driving signal is then applied to the HID lamp. A method of operating an HID lamp is also provided. Power is coupled to an HID lamp with a selectable power signal where the power signal is selectable for full power or reduced power operation.

Abstract: A gas discharge lamp is driven using a high frequency lamp current. A lamp driving circuit comprises a high frequency bridge circuit for supplying said lamp current. To prevent the lamp from extinguishing, when the lamp voltage is lower than a predetermined lamp operation voltage, a resonant circuit is provided in the lamp driving circuit between the lamp and the high frequency bridge circuit. The frequency of the bridge circuit is selected such that the resonant circuit may resonate to sweep up the voltage supplied to the gas discharge lamp to a voltage higher than said lamp operation voltage.

Abstract: An igniter circuit (140) for an electronic lamp driver (100) for driving a gas discharge lamp (6) is described, the igniter circuit comprising: first and second supply input terminals (102, 103); a switch branch (110) comprising a first controllable ignition switch (111) and a second controllable ignition switch (112) connected in series between said first and second supply input terminals (102, 103); a transformer (33) having a primary winding (41) and a secondary winding (32); an igniter coil (42) connected in series with said primary transformer winding (41), this series arrangement having one end (42b) connected to a node (D) between said two controllable ignition switches (111, 112); a storage capacitor (44) connected between another end (41b) of said series arrangement and one of the supply input terminals (102, 103).

Abstract: Bi-state power operation of an HID lamp system. A power mode control selection determined where a high power mode and a low power mode are selectable. A modulation is determined to generate a driving signal based on the determined power mode control selection. A driving signal is generated based on the determined modulation. The generated driving signal is then applied to the HID lamp. A method of operating an HID lamp is also provided. Power is coupled to an HID lamp with a selectable power signal where the power signal is selectable for full power or reduced power operation.

Abstract: The invention relates to an apparatus for supplying electrical energy at high frequencies to HID-lamps, comprising at least a first high frequency voltage source adapted to generate a substantial sinusoidal voltage with a fist frequency and a first amplitude, at least a first piezoelectric transformer of which the resonance frequency is substantially equal to the first frequency and which is connected to said first voltage source, a number of secondary voltage sources which are each adapted to generate a substantial sinusoidal voltage with a frequency which is an odd harmonic of the first frequency and an amplitude which is an odd fraction of the first amplitude and a number of piezoelectric transformers of which the connected to the second voltage source.

Abstract: Circuit for providing power to a load with a pre-determined specification, comprising:—a transformer having a primary winding and a secondary winding, said secondary winding being part of a resonant circuit;—first and second load connection nodes for coupling of the load in series to the secondary winding;—a switch coupled in series to the primary winding, an on and off-time of the switch being controllable by a control element, for generating a voltage pulse over the primary winding; wherein a diode is coupled in parallel to the primary winding for demagnetizing the transformer during the off-time of the switch, the on and off-time of the switch being predetermined. The diode provides a free-running path to demagnetize the transformer if the switch is off. To prevent saturation of the core of the transformer, a subsequent voltage pulse is only applied to the circuit if the free-running current through the diode has become substantially zero.