Modular high frequency ballast architecture
AssigneePhilips Electronics North America Corporation
InventorIhor T. Wacyk
Life of this patent
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Abstract
A modular high frequency ballast for two or more lamps. The modules are driven in an interleaved or non-interleaved switching manner. Independent lamp operation is provided for fixed and dimming circuits. A reduction in the size and cost of the preconditioner stage is achieved through the interleaved switching operation. The modules can be standardized for operating a broad range of lamps.
Claims19
A modular high frequency ballast for powering at least two lamps, comprising:
- a module for each lamp,
- each module including at least one inverter;
- and
- a controller for independently operating each module,
- said controller responsive to at least one feedback signal from each lamp,
- each feedback signal corresponding to at least one of a lamp voltage and a lamp current of each lamp, and
- the controller being configured to generate driving signals for controlling the switching frequency of each inverter;
- wherein:
- at least two modules are operated substantially 180° out of phase from each other and
- the controller, in response to the feedback signal, adjusts duty cycles of the driving signals supplied to each inverter.
A method for individually operating two lamps from one ballast, comprising:
- supplying a first driving signal to a first inverter for igniting a first of the two lamps;
- continuing to supply the first driving signal to the first inverter for increasing the voltage applied to the first of the two lamps following its ignition until the first of the two lamps reaches steady state operating conditions;
- supplying a second driving signal to a second inverter for igniting a second of the two lamps only after the first of the two lamps reaches its steady state operating conditions;
- continuing to supply the second driving signal to the second inverter for increasing the voltage applied to the second of the two lamps following its ignition until the second of the two lamps reaches its steady state operating conditions.
A modular high frequency ballast for powering at least two lamps, comprising:
- a module for each lamp,
- each module including at least one inverter;
- and
- a controller for independently operating each module,
- said controller responsive to at least one feedback signal from each lamp,
- each feedback signal corresponding to at least one of a lamp voltage and a lamp current of each lamp.
A modular high frequency ballast for powering at least two lamps, comprising:
- a module for each lamp,
- each module including at least one inverter;
- and
- a controller for independently operating each module,
- said controller responsive to at least one feedback signal from each lamp,
- each feedback signal corresponding to at least one of a lamp voltage and a lamp current of each lamp;
- wherein
- at least one module further includes
- a filament heating transformer and
- a resonant LC circuit,
- at least one module including a first inverter and a second inverter,
- wherein
- the first inverter supplies power through the resonant LC circuit to illuminate a first lamp and
- the second inverter supplies power through the filament heating transformer to condition the first lamp during a preheat phase of the first lamp.
Dependencies are inferred from the claim text.