Abstract: An electronic ballast embodiment of the present invention comprises a half-bridge parallel-loaded series resonant converter (HB-PLSRC) circuit a load is connected across a resonating capacitor with DC blocking capacitors in each of two legs and in series with a resonating inductor. The combination is connected to the junction of two switches wired in series across a DC source input such that the resonant inductor and resonant capacitor are connected across one of the switches. A coordinated manipulation of the switches is then used to charge and discharge the resonant inductor and resonant capacitor are pumped in series resonance. Alternatively, the load is connected through an isolation transformer.

Abstract: A fluorescent lamp fixture embodiment of the present invention comprises a frame module, a ballast module, a socket housing module and a reflector module that all interconnect via a standardized connection system. The ballast module is attached to a ballast plate and snaps onto a junction box wrapper that has a junction box baseplate. The frame module snaps onto the junction box wrapper together with the socket housing module. The reflector module also attaches directly to the frame module.

Abstract: An embodiment of the present invention is a ballast for a high intensity discharge lamp that includes a non-automatically resetting thermal protector thermally coupled to a coil wound on a core and insulation between the coil and the core. Only one cycle is allowed into what may be a range of temperatures capable of destroying the insulation within the ballast.

Abstract: An embodiment of the present invention is a luminaire for roughly uniform illumination of a square area without side glare. The luminaire uses a horizontally oriented arc tube lamp. A basket reflector surrounds the arc tube lamp and directs light out in a square pattern. A top aperture in the basket reflector is opposite to the illuminated square area. A bottom aperture, positioned in the basket reflector, permits light from the arc tube lamp to pass out to the illuminated square area. A center reflector is centrally positioned above the top aperture and has bow-tie shaped body and a pair of ends that are orthogonally oriented to the arc tube lamp. A pair of side reflectors with a plurality of faceted reflective surfaces receive light from the arc tube lamp that has been reflected from the center reflector. The side reflectors are positioned at opposite points outside the basket structure and are centered along a line perpendicular to the arc tube lamp.

Abstract: An embodiment of the present invention is a lighting system including a sense transformer with two primaries and a secondary for receiving alternating current (AC) from a power source, a low ohmage resistor placed across the sense transformer secondary winding for preventing saturation of the core of the sense transformer, an analog comparator for detecting when ground-fault signals in the sense transformer secondary winding exceed a threshold voltage and digital counters for testing whether or not a ground-fault condition persists longer than three consecutive half-cycles of the received alternating current from the power source.

Abstract: An embodiment of the present invention is a lighting system comprising a full-wave bridge, a filter capacitor, a control logic that drives a pair of output transistors and an output network that includes an output transformer that powers a pair of fluorescent lamps. The output transformer has a natural resonant frequency that will produce maximum power transfer to the lamps if the transistors are switched by the control logic at a rate near the natural resonant frequency. Precise frequency control within the control logic maintain consistent levels of output current through the lamps by phase lock loop (PLL) synchronizing its output switching frequency to the sixty Hz commercial line frequency, as sampled through a resistor and a digital integrator that prevents false triggering.

Abstract: A fluorescent lamp system utilizes boost power factor correction. The fluorescent lamp system includes a power source, a reference voltage and a fluorescent lamp. A resonant circuit supplies power to the fluorescent lamp. A first capacitor is connected between a first end of the resonant circuit and the reference voltage. A second capacitor is connected between the first end of the resonant circuit and the power source. A first switch is connected between a second end of the resonant circuit and the reference voltage. A second switch is connected between the second end of the resonant circuit and the power source. A control module operates the first switch and the second switch so that the resonant circuit operates at near resonant frequency. The control module is integrated on a single integrated circuit. The first switch and the second switch may be also integrated on the single integrated circuit.

Abstract: In a ballast circuit for producing a DC signal with a high voltage amplitude, a capacitor is connected to a circuit output. The capacitor stores a charge which provides the high voltage amplitude of the DC signal. Current from an inductor is used to charge the capacitor. A current gate, when it is turned on, drains current from the inductor. A control circuit turns the current gate on and off so that the amplitude of the current drawn from the incoming AC voltage signal is in phase with the amplitude of the voltage of the incoming AC voltage signal. The control circuit includes a ramp generator which generates a pulse modulation reference signal with a varying voltage amplitude and a comparator which compares the pulse modulation reference signal with the incoming AC voltage signal after the incoming AC voltage signal has been rectified and the voltage divided by a voltage divider. The comparator produces a first modulated signal.

Abstract: A lamp fixture housing is mounted recessed in a ceiling. A slide member is positioned within the housing and slides within two vertical slots located in the housing wall. A lamp assembly is connected to the slide member. A lever arm is pivotally connected to the housing and passes through a central slot in the slide member. The lever arm holds the slide member and lamp assembly in the desired position.

Abstract: Power is provided to a fluorescent lamp through a single integrated circuit (IC) chip. The IC chip contains control logic and power switches. The control logic operates the switches at a frequency which is optimum for the fluorescent lamp. The control logic includes circuits for thermal shut down, load status detection and voltage compensation.