Ballast circuit having enhanced output isolation transformer circuit
OwnerMihail S. Moisininventor
Life of this patent
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Abstract
A ballast circuit includes an output isolation transformer having a primary winding and first and second secondary terminals coupled to opposing ballast lamp terminals for additively applying potentials on the primary winding and the first and second secondary winding potentials across the lamp and limiting ground fault voltages. The circuit can include a closed loop feedback path from a load to a feedback rectifier for promoting linear operation of an input rectifier.
Claims47
A resonating circuit, comprising:
- a transformer having a primary winding and a first secondary winding, wherein the first secondary winding is electrically connected to the primary winding with a node at AC ground disposed between the first secondary winding and the primary winding such that a potential on the primary winding and a potential on the first secondary winding combine to energize a load.
A method for providing ground fault protection in an AC circuit, comprising:
- dividing a load voltage between a primary winding and a secondary winding by placing an AC ground between the primary winding and the secondary winding.
A ballast circuit, comprising:
- a resonant inverter;
- a transformer having a primary winding and first and second secondary windings, wherein the primary winding corresponds to a resonant inductive element of the resonant inverter, the first and second secondary windings being electrically coupled to opposing ends of the primary winding such that voltages on the primary winding and the first and second secondary windings are adapted for being additively applied across a lamp.
A method for providing ballast ground fault protection, comprising:
- providing a resonant inverter including a transformer having a primary winding;
- electrically coupling first and second secondary windings to the primary winding of the transformer such that voltages on the first and second secondary windings and the primary winding are additively applied across a lamp.
A circuit, comprising:
- a first rectifier;
- a resonant circuit coupled to the first rectifier, the resonant circuit including a transformer having a primary winding electrically coupled to a secondary winding;
- a second rectifier coupled to the first rectifier and the resonant circuit;
- and
- a feedback path from the resonant circuit to a point in the second rectifier for promoting linear operation of the first rectifier.
Dependencies are inferred from the claim text.