Universal Lighting Technologies, Inc.

Steve Mays

John Jay Dernovsek

Philip Walker

A lighting device such as an electronic ballast or LED driver includes a power factor correction (PFC) controller responsive to input power supply signals to generate control signals, a PFC boost converter responsive to said control signals to generate a boosted output voltage, and a fast start circuit with a power supply source and an energy storage device, a magnitude of the input power supply signal corresponding to energy stored in the energy storage device. During a first mode, the fast start circuit responds to a rectified mains input to enable the power supply source and charge the energy storage device. During a second mode, the fast start circuit responds to a magnitude of the power supply signal to disable the power supply source and discharge the energy storage device. The boost converter during the second operating mode maintains controller operation while the power supply source is disabled.

Lighting device including a fast start circuit for regulating power supply to a PFC controller

An electronic ballast circuit includes a filament drive circuit that can adjust the pulse width of a pulsed heating signal in accordance with the lamp current to a gas-discharge lamp. A logic device, such as an SR flip-flop, is used to control a switch that is coupled to the primary winding of a filament drive transformer coupled to the lamp filaments. The logic device opens and closes the switch device to generate the pulses of the pulsed heating signal and thus controls the pulse width of the pulses. A clock signal triggers logic device to start a pulse while the end of the pulse is determined by a signal level across a resistor in series with the primary winding of filament drive transformer. Once this signal level is at or above a threshold level, logic device switches the switch device to end the pulse.

Ballast circuit for a gas-discharge lamp having a filament drive circuit with monostable control

A method of controlling a series-resonant, half-bridge inverter includes turning off the bottom switch and turning on the top switch the inverter when the current through the resonant inductor crosses the zero axis while the current is increasing, thereby insuring zero voltage switching of the inverter switches and increases the overall switching period so that the actual inverter frequency is closer to the resonant frequency of the series-resonant circuit. Using an on-time control circuit, the method further includes controlling the current delivered to the load (such as a gas discharge lamp) by varying the on-time of the top inverter switch.

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Madison, AL, United States of America

Steve Mays