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: 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 method for dimming a gas discharge lamp (2), particularly a HID lamp, and more specifically a MH lamp, is described. The lamp is operated at nominal power with commutating DC current having a current magnitude IL=?Inom, ? being equal to 1 or less than 1. The current magnitude IL is reduced, but the lamp still is operated at commutating DC current, until a reaches a predetermined value ?. Then, the lamp is operated at DC current, and the current magnitude is reduced further. It is now possible to achieve a lower dimming level.

Abstract: The present invention provides a high frequency electronic ballast with rail voltage switching which adjusts the DC rail voltage output (208) to account for different voltages of mains power (210), improving efficiency. The rail voltage switching comprises a mains power supply (200) providing mains power (210) and a mains voltage signal (212); a ballast microcontroller (206) responsive to the mains voltage signal (212) and generating a power factor correction (PFC) voltage signal (214); and a converter (204) operably connected to the mains power supply (200) and responsive to the PFC voltage signal (214) to generate a DC rail voltage output (208). For an embodiment using power factor control, the converter (204) comprises a coil (218), power factor correction (224), a switch (220), and a rectifier (222).

Abstract: The present invention relates to a switch mode power supply for igniting and operating a high-pressure gas discharge lamp (2), comprising an ignition sub-circuit (20) which is coupled via a transformer (14) to the circuit, wherein the ignition sub-circuit comprises: -at least an ignition capacitor (22); -a switching element (30) for discharging the capacitor at a desired moment in time having a control electrode; wherein the control electrode of the switching element is connected to the commutator (6, 7, 10, 16, 18) of the lamp circuit via a control sub-circuit (32, 34, 36, 38) which comprises substantially passive elements.

Abstract: An auxiliary lighting system for a high-intensity discharge lamp. In one embodiment, the auxiliary lighting system has an auxiliary light source, an HID lamp status circuit having an input for connection to a status signal representative of the operational state of a high-intensity discharge lamp wherein the HID lamp status circuit determines whether the status signal meets predetermined signal criteria, a switch circuit having a first state that effects application of a voltage source to the auxiliary light source, and a second state that isolates the voltage source from the auxiliary light source, and a control circuit responsive to the HID lamp status circuit for controlling the switch circuit. The control circuit has a first state when the HID lamp status circuit determines that the status signal meets the predetermined signal criteria and a second state when the HID lamp status circuit determines that the status signal does not meet the predetermined signal criteria.

Abstract: An auxiliary lighting system for a high-intensity discharge lamp. In one embodiment, the auxiliary lighting system has an auxiliary light source, an HID lamp status circuit having an input for connection to a status signal representative of the operational state of a high-intensity discharge lamp wherein the HID lamp status circuit determines whether the status signal meets predetermined signal criteria, a switch circuit having a first state that effects application of a voltage source to the auxiliary light source, and a second state that isolates the voltage source from the auxiliary light source, and a control circuit responsive to the HID lamp status circuit for controlling the switch circuit. The control circuit has a first state when the HID lamp status circuit determines that the status signal meets the predetermined signal criteria and a second state when the HID lamp status circuit determines that the status signal does not meet the predetermined signal criteria.

Abstract: Igniter circuitry for a gaseous discharge lamp includes an inductive igniting pulse generating circuit and a capacitive timing circuit. The pulse generating circuit includes a unidirectional voltage-sensitive switch which is electrically connected in series with a capacitor in the timing circuit to unidirectionally limit common current.

Abstract: An improved high intensity discharge ("HID") ignition circuit for a ballast uses a gapped transformer with a capacitor placed across the secondary thereof. The ballast includes a DC source, a down converter, a commutator, and the ignition circuit. The output of the commutator is supplied to the secondary winding of the gapped transformer and the lamp, which are connected in series. The lamp is an HID lamp such as, for example, a metal halide lamp, high pressure sodium lamp, high pressure mercury lamp, or a metal vapor lamp. Power is furnished to the lamp over a cable. Ignition of the lamp is handled by the ignition circuit, which in addition to the secondary winding and the capacitor includes an inductor, the primary winding of the gapped transformer, two SIDACs, and the parallel combination of a resistor and a capacitor, all connected in series between the output of the down converter.