Master-slave half-bridge DC-to-AC switchmode power converter
AssigneeLED Corporation N.V.
InventorsOscar Vila-Masot, Janos Melis
Life of this patent
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Abstract
The invention pertains to a switchmode DC to AC converter, and particularly to a master-slave half-bridge converter. The slave half-bridge power converter is controlled by a lower power self-oscillating half-bridge master converter. More particularly, the invention pertains to a high frequency ballast for gas discharge devices, especially, for high pressure sodium lamps, completed by a high voltage ignition apparatus. A pair of self-saturated electronically switched transformers controlled by a low power current source provide a power controlled and frequency modulated high frequency ballast for the gas discharge devices.
Claims8
A master-slave half-bridge DC-to-AC switchmode power converter comprising:
- a DC power supply;
- a self-oscillating half-bridge switchmode converter acting as a low power master converter connected to said DC power supply, said master converter provided with a master control transformer having at least five windings, two controlled master switches, first and second self-saturated transformers, each of said self-saturated transformers connected between said master control transformer and each of said master switches;
- and
- a half bridge switchmode converter acting as a controlled slave power converter connected to said DC power supply and said low power master converter, said slave power converter provided with two slave switches, first and second electronic control means for controlling said slave switches, each of said electronic control means connected between said control transformer and each of said slave switches, said slave power converter further including a load impedance;
- a pair of voltage divider capacitors common to said master converter and said slave converter;
- and
- a low power current source connected between said first and second self-saturated transformers for providing a power controlled and frequency modulated high frequency ballast for said load impedance and for providing said first and second self-saturated transformers with an equal biasing magnetizing force;
- wherein the ON and OFF states of each of said master and slave switches are controlled by said self-oscillating half-bridge switchmode converter.
Dependencies are inferred from the claim text.