Abstract: A high pressure discharge lamp lighting device comprising an inverter, an igniter, a controller, a pulse voltage detection circuit, and the starting pulse voltage regulation circuit. The inverter applies a lighting voltage to a high pressure discharge lamp. The controller applies the starting pulse voltage generated by the igniter to the high pressure discharge lamp. The pulse voltage detection circuit is configured to detect a voltage indicative of the starting pulse voltage to output a detection signal. The starting pulse voltage regulation circuit is configured to regulate the starting pulse voltage to a desired value of the starting pulse voltage on the basis of the detection signal. The pulse voltage detection circuit is configured to detect either one of the voltage developed in the specified circuit component of the igniter and the starting pulse voltage as the voltage indicative of the voltage indicative of the starting pulse voltage.

Abstract: An electronic ballast includes a ballast control circuit controlling an inverter circuit to supply a rectangular wave AC power to a high-pressure discharge lamp. The ballast control circuit includes a load voltage detection circuit adapted to detect load voltages of both positive and negative polarities applied to the lamp, a comparison and selection circuit adapted to compare the detected load voltages of the positive and negative polarities and select one of the positive and negative polarities, and a switching control circuit adapted to use the load voltage of the polarity selected by the comparison and selection circuit for controlling load current in one cycle after a period of detecting the load voltages of both the positive and negative polarities.

Abstract: One output power characteristic curve for supplying constant power is provided with respect to a raging voltage range of a discharge lamp, and in addition, a plurality of output power characteristic curves W1, W2 and W3 are provided with respect to a lamp voltage before the rating voltage range. There is provided minimum lamp voltage detecting means for detecting a minimum lamp voltage after a high intensity discharge lamp shifts to an arc discharge in an event where lamp power is supplied to a high intensity discharge lamp based on any initially set output power characteristic curve after the high intensity discharge lamp is started. As the minimum lamp voltage detected by the minimum lamp voltage detecting means is larger in a predetermined minimum lamp voltage range, any larger output power characteristic curve is reset from the plurality of output power characteristic curves W1, W2 and W3, and subsequent power control is performed.

Abstract: A discharge lamp ballast is provided for powering a discharge lamp with feedback filament heating control. A startup circuit is coupled between output terminals of a DC-AC power converter together with a discharge lamp. A lamp current detection circuit and a lamp voltage detection circuit detect output signals to the lamp. A control circuit controls the switching elements and generates an operating frequency in accordance with a startup operation to generate a high voltage output from the startup circuit and ignite the discharge lamp, a filament heating operation wherein the operating frequency is controlled so as to set the amplitude of the output current detected by the lamp current detection circuit to a target current amplitude based on the amplitude of the output voltage detected by the lamp voltage detection circuit, and a steady-state operation wherein the operating frequency is decreased to maintain a stable light output from the discharge lamp.

Abstract: A discharge lamp ballast is provided with a feedback control operation to provide optimal lamp current flow during an electrode heating operation. A startup circuit coupled together with a discharge lamp between output terminals of a DC-AC power converter having a plurality of switches. The startup circuit generates a high voltage to ignite the lamp. A lamp current sensor detects an amplitude of an output current to the lamp. A control circuit controls the switches in accordance with each of a plurality of control operations including a startup operation to ignite the lamp using the high voltage generated by the startup circuit, an electrode heating operation wherein an operating frequency of the switches is controlled to set the amplitude of the detected output current to a predetermined target current amplitude, and a normal operation wherein the operating frequency is reduced to maintain stable lighting of the lamp.

Abstract: An electronic ballast provides a ballast housing including a circuit board electrically and mechanically connected to the ballast housing by an electrically conductive spacer. The circuit board includes a ground electrode surrounding a clearance hole through which an electrically conductive fastener is inserted into a fastener hole located in the spacer. An insulating filler is disposed in the ballast housing between the housing interior surface and the circuit board. A lighting fixture including an electronic ballast is also provided.

Abstract: An electronic ballast is provided for powering a high-pressure discharge lamp. A power supply circuit receives an AC input and provides a DC output in response to the AC input. An inverter circuit having a plurality of switching elements converts the DC output into an AC signal for the lamp. An LC resonant circuit is coupled between the inverter circuit and the lamp. A control circuit controls the switching operation of the switching elements, with the switching control associated with various operating modes. In an electrical breakdown mode the switching elements are controlled at a first switching frequency effective to provide a first resonant voltage and produce electrical breakdown of the lamp from an unlit state. In a high frequency preheat mode the switching elements after startup of the lamp are controlled at a second switching frequency lower than the first switching frequency to provide a current for preheating lamp electrodes.

Abstract: An electronic ballast is provided for powering a discharge lamp and suppressing lamp flicker during startup transition. A power converter receives DC input power and converts it into an AC power output. A resonant circuit is coupled with the lamp and also between output terminals of the power converter. A controller controls the power converter with respect to particular modes of operation. The controller in a starting operation sets the output frequency of the power converter to a predetermined start frequency upon lamp startup to make the lamp begin discharging. The controller shifts from the starting operation to steady-state operation by setting the output frequency of the power converter at a predetermined steady-state frequency lower than the start frequency.

Abstract: A high pressure discharge lamp lighting device includes a DC power source circuit; a power supply circuit for converting an output from the DC power source circuit into a square wave AC output to be supplied to a high pressure discharge lamp; a starting circuit for applying a high voltage output for lamp startup to the high pressure discharge lamp; a control circuit; and a half-wave discharge detection circuit for detecting a half-wave discharge. The detection circuit detects the half-wave discharge at an initial stage of the lamp startup and the control circuit controls the magnitude of a voltage of a square wave half period of one polarity having a load voltage of a larger magnitude and that of a square wave half period of the other polarity having a load voltage of a smaller magnitude to approximate to each other.

Abstract: A high pressure discharge lamp lighting device, includes: a DC/DC converter for converting a power source voltage of a DC power source into a desired DC voltage and stably lighting a high pressure discharge lamp; a DC/AC inverter for inverting the DC voltage into an AC voltage; and a starting pulse generating circuit for generating a high voltage required for the start-up of the high pressure discharge lamp. Further, the high pressure discharge lamp lighting device includes a lighting state decision unit for deciding a lighted/unlighted state of the high pressure discharge lamp; and an operating state switching control unit for switching the operating state of at least one of the DC/DC converter, the DC/AC inverter, and the starting pulse generating circuit to another operating state, depending on a predetermined operation phase out of the start-up, stable lighting and power interrupt phases of the high pressure discharge lamp.

Abstract: A high-voltage discharge lamp lighting device provides a starting pulse voltage sufficient to turn on a high-voltage discharge lamp having terminal wire connections of variable length. A power conversion circuit is coupled to a commercial AC power source input and rectifies the AC input into a predetermined DC voltage output. A charging capacitor is coupled to the power conversion circuit. A full bridge circuit is coupled to the power conversion circuit and the charging capacitor and provides a rectangular wave AC output signal to a transformer primary winding circuit of at least a capacitor, a single switching element and a primary winding of a transformer. A low pulse voltage is induced in the primary winding and a transformer secondary winding is connected on one end to the high-voltage discharge lamp, wherein the low pulse voltage is stepped up to a high pulse voltage and applied to the high-voltage discharge lamp.

Abstract: In order to optimally control power outputted from a high intensity discharge lamp lighting device for a difference among loads connected thereto, such as a difference in gas components contained in arc tubes and a difference in shape of the arc tubes individually in a plurality of discharge lamps 11, plural kinds of output power characteristics W1, W2 and W3 as data tables of lamp voltage-lamp power are provided for a rating lamp voltage range of each of the high intensity discharge lamps 1 and a lamp voltage range lower than the rating lamp voltage range, there is provided minimum lamp voltage detecting means 7 for allowing predetermined power to be outputted in an event of starting the high intensity discharge lamp 11, and detecting a minimum lamp voltage Vmin after the high intensity discharge lamp shifts to an arc discharge, and in response to that the detected minimum lamp voltage Vmin enters any range of a plurality of preset voltage ranges A, B and C, any of the data tables W1, W2 and W3 of the lamp v