Koninklijke Philips Corporation N.v.

Philips Lighting Holding B.v.

Arun Ganesh

Yuhong Fang

Yimin Chen

Bruce Robeson Rhodes

George Grouev

Romel Panlilio

Sanjaya Kumar Pradhan

Alejandro Lopez

Sree Venkit

Guangyi Luo

An electronic ballast with power thermal cutback including an electronic ballast operably connected to provide power to a lamp, the electronic ballast having a PFC converter (HO) operable to receive a PFC input voltage () and operable to provide a DC bus voltage on a DC bus (); a DC/AC converter () operable to receive the DC bus voltage from the DC bus () and to provide AC power () to the lamp () at an AC output frequency; a compensator () responsive to an electronic ballast condition parameter, the compensator () being operable to provide a compensator signal to at least one of the PFC converter () and the DC/AC converter (). At least one of the PFC converter () and the DC/AC converter () is responsive to the compensator signal to reduce the power to the lamp () when the electronic ballast condition parameter passes a threshold.

Electronic ballast with power thermal cutback

An electronic ballast and startup method including an electronic ballast operably connected to a lamp having a lamp filament, the electronic ballast having a timer () generating an inverter control signal () and a preheat control signal (); a converter () receiving AC power and generating DC power (); a self-oscillating inverter () receiving DC power () and being operable to provide lamp power () to the lamp, the self-oscillating inverter () being responsive to the inverter control signal (); and a filament preheater () receiving DC power () and being operable to provide filament power () to the lamp filament, the filament preheater () being responsive to the preheat control signal (). When AC power is initially applied, preheat control signal () directs the filament preheater () to provide filament power (), and inverter control signal () directs the self-oscillating inverter () not to provide lamp power ().

Electronic ballast and startup method

A switch mode power supply () employs a rectifier (), a converter () and converter driver (). The rectifier () generates a rectified supply voltage (V) based on an in-line voltage (V), and the converter driver () generates one or more driving voltages (V) to facilitate a conversion by the converter () of the rectified supply voltage (V) to a DC bus voltage (V) based on the driving voltage(s) (V). The converter () may include a transient voltage suppression device () to suppress the rectified supply voltage (V) in response to an abnormal line condition of the switch mode power supply (), and the converter driver () may include a free-oscillating suppression device () to suppress the one or more driving voltages (V) in response to a free-oscillating condition of the converter driver ().

Switch mode power supply for in-line voltage applications

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Aurora, IL, United States of America

Arun Ganesh