Abstract: A ballast to power a lamp includes two switches, each to selectively connect the ballast to respective high voltage terminals, each having two states (ON and OFF). The ballast also includes a converter circuit that provides a voltage to energize the lamp, and a detector circuit. The detector circuit includes two inputs, each coupled to a respective switch; two resistors, each coupled to a respective input; two outputs, each connected to the converter circuit; a transistor network; and a capacitor. One output provides the converter circuit with power, and is connected to the input via the resistors. The other provides the converter circuit with a control signal, indicating a voltage level so as to power the lamp to a particular light level, depending on the switches' states. The transistor network detects a differential voltage between the inputs, generating the control signal as a result. The capacitor smoothes the control signal.

Abstract: A lamp including a two-sided source plate, a plurality of light sources, a lens, a diffuser plate, and a driver insulator is disclosed. One set of the light sources generates white light and is attached to one side of the source plate. Another set of the light sources generates colored light and is attached to the source plate's other side. The lens encapsulates the white light-generating set, and redirects that white light. The driver insulator and the diffuser plate are each in contact with the source plate's other side. The driver insulator, diffuser plate, and that side of the source plate define a light box region that contains the colored light-generating set of light sources. The driver insulator acts as a reflector, and the diffuser plate acts as a diffuser, such that colored light is dispersed from the light box region through the diffuser plate.

Abstract: End-of-life indicators for lamps, and methods for indicating the end-of-life for lamps, are provided. A solid state light source end-of-life indicator is located on the exterior of a housing of a lamp, and includes at least one light emitting diode. The solid state light source end-of-life indicator emits light at the end of the life of the lamp. The solid state light source end-of-life indicator may emit light upon receiving an end-of-life signal from an end-of-life detection circuit, which detects when the lamp is at an end of its life.

Abstract: An operating resonant load circuit, a dimming circuit and a dimming method are disclosed. The operating resonant load circuit includes: an input unit including a plurality of input terminals, for receiving an AC voltage; a rectifier, for transforming the AC voltage received by the input unit into a DC bus voltage; and a controller, for dividing the DC bus voltage based on an conducting status of the input terminals to output a corresponding DC reference voltage. The dimming circuit and dimming method use the operating resonant load circuit to perform dimming.

Abstract: A light emitting diode (LED) lamp includes a base with one or more LED chips, an internal cover over the LED chips, where the cover is a translucent ceramic whose thermal conductivity is greater than glass, where the cover has an interior surface separated from the LED chips by a gap, and where an exterior surface of the cover is coated with a phosphor. The ceramic cover preferably has a bulk thermal conductivity of at least 5 W/(m·K), such as polycrystalline alumina. The LED chips preferably are blue LEDs and the phosphor is selected so that the lamp emits white light. In the method of making the lamp, the phosphor may be applied to the exterior surface of the cover as a preformed sheet or in a coating.

Abstract: A lamp assembly includes a lamp base having power input terminals, a fluorescent lamp connected to the terminals through a manually operated switch that is on an exterior of the lamp base so that when power is supplied to the terminals the fluorescent lamp is selectively powered by manual operation of the switch, and a light emitting diode (LED) inseparably connected to the terminals so that when power is supplied to the terminals the LED is always powered. This arrangement allows the LED to be ON regardless of the operating status of the fluorescent lamp and allows the fluorescent lamp to be turned OFF while the LED remains ON.

Abstract: Solid state light source driving and dimming systems are provided that enable a plurality of solid state light source (e.g., LED) driver circuits to be coupled to a single AC voltage source. The driver circuits may include constant current circuitry configured to generate a constant AC current from the AC voltage source, and rectifier circuitry configured to generate a DC current to drive the solid state light source (e.g., LEDs). Dimming control includes shunt circuitry operable with a PWM switch to shunt the AC voltage source during certain portions of a PWM signal and to decouple the shunt circuitry from the AC voltage source during other portions of the PWM signal. Shunting the AC voltage source causes the interruption of the DC current to effectively turn off the LEDs. Decoupling the shunt circuitry may improve overall efficiency of power transfer to the LEDs.

Abstract: A ballast (10) for powering one or two gas discharge lamps (30,40) includes an inverter (100), an output circuit (200), and a control circuit (500). During a period prior to startup of inverter (100), control circuit (500) monitors a signal within output circuit (200) in order to determine the presence of lamps with intact filaments that are present at the ballast output connections (202,204, . . . ,210,212). Preferably, control circuit (500) is realized by a programmable microcontroller which implements a dual timing scheme in order to accurately determine the number of lamps with both filaments intact. The resulting determination may be used for various purposes, such providing appropriate levels of filament heating and/or for setting thresholds for accurately detecting and protecting against various lamp fault conditions.

Abstract: An electronic control gear for a HID lamp receives an input signal for operating the lamp and frequency modulates the input signal to generate a frequency modulated output signal that drives an arc of the lamp. The frequency modulation of the output signal sweeps continuously between a low frequency modulation and a high frequency modulation, the low frequency modulation being a frequency f1 in a range of 125 kHz to 150 kHz and the high frequency modulation being a frequency f2 in a range of 230 kHz to 300 kHz, where f2?f1 is at least 0.4*f1. A power amplifier changes an amplitude of the frequency modulated output signal during the low frequency modulations so that a current amplitude of the frequency modulated output signal is substantially constant, and a variable gain transformer adjusts a voltage of the frequency modulated output signal during starting of the lamp.

Abstract: Lamp connectors are provided. The lamp connectors include a swinging connector and a rotatable connector. The swinging connector is coupled to a pivot connection point disposed on a first exterior surface of a lamp. The swinging connector is operative to pivot between a first position close in proximity to the lamp and a second position at distance away from the lamp. A portion of the swinging connector may be received and retained by a second exterior surface of the lamp, when the lamp is in the first position. The rotatable connector is attached to an end of a lamp via a rotation mechanism. The rotation mechanism is disposed on the end of the lamp. The rotatable connector includes a surface and a pin protruding therefrom. The pin is offset from a central portion of the end of the lamp.

Abstract: A ballast (10) for powering one or more gas discharge lamps (30,40) includes an inverter (100), an output circuit (200), a filament heating control circuit (300), and a control circuit (500). During a lamp filament detection period prior to startup of inverter (100), control circuit (500) monitors a signal within output circuit (200) in order to determine the number of lamps with intact filaments that are present at the ballast output connections (202, 204, . . . , 210, 212). During a lamp type detection period following startup of inverter (100), control circuit (500) monitors a current within filament heating control circuit (300) in order to determine the type of lamp(s) present at ballast output connections (202, 204, . . . , 210, 212). The determinations as to the number of lamps and the type of lamps are utilized by control circuit (500) to provide an appropriate level of heating to the lamp filaments.

Abstract: A transient voltage protection circuit that protects a load from transient voltages is disclosed. The circuit includes a series combination of a thyristor surge protection device (TSPD), a resistor and a transorb coupled for coupling in parallel with the load, and a fuse coupled between an AC input and the series combination. The TSPD and the transorb are configured to enter a transient mode upon application of a transient voltage to the circuit to shunt current from the load and provide an AC output voltage to the load less than the transient voltage without opening the fuse.

Abstract: A radio frequency (RF) power supply for an electrodeless lamp includes a pair of DC rails, an RF inverter having power input terminals connected between the rails, a first inductor arranged to inductively couple with an electrodeless lamp, first and second resonance capacitors that each connects a respective one of two input terminals of the first inductor to a same first rail of the pair of DC rails, and a second (ballasting) inductor connecting an output of the RF inverter to one of the two input terminals of the first inductor. Thus, the first inductor is connected in a symmetrical ?-filter and supplied by two equal but phase-opposite voltages whose sum is the lamp voltage. The inductance of the ballasting inductor is significantly reduced so that the RF efficiency of the power supply is 96%.

Abstract: A control circuit for a lamp. The control circuit is used in conjunction with an alternating current (AC) variable voltage power source to energize the lamp. The control circuit includes a voltage sensing component for sensing the voltage of an voltage input signal from the power source for energizing the lamp. The control circuit includes a controller configured to estimate a delay angle as a linear function of the sensed voltage. The control circuit includes an AC converter for modifying the voltage input signal according to the estimated delay angle to generate an AC voltage output signal having a constant root mean square voltage for energizing the lamp.

Abstract: An illuminator is disclosed, in which an LED module emits short-wavelength light toward a phosphor module, which absorbs it and emits wavelength-conditioned light. The emission is generally longitudinal, with a generally Lambertian distribution about the longitudinal direction. The phosphor module includes a transparent layer, closest to the LED module, and a phosphor layer directly adjacent to the transparent layer. Both layers are oriented generally perpendicular to the longitudinal direction. The illuminator includes a reflector, circumferentially surrounding the emission plane in the LED module and extending longitudinally between the emission plane and the transparent layer. Virtually all the light emitted from the LED module either enters the phosphor module directly, or enters after a reflection off the reflector.