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US 5,510,974 AGranted
High frequency push-pull converter with input power factor correction
AssigneePhilips Electronics North America Corporation
InventorsWen-Jian Gu, Rui Liu
Life of this patent
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Abstract
A single stage high frequency push-pull converter with input power factor correction. The boost converter for input power factor correction and the high-frequency push-pull DC/AC inverter are combined into a single stage converter thereby reducing the number of circuit components while at the same time reducing the voltage stress on the high frequency switching transistors of the converter.
Claims20
A single stage boost converter and high-frequency DC/AC power inverter apparatus comprising:
- a pair of input terminals for connection to a source of AC voltage,
- rectifier means having an input coupled to said pair of input terminals and an output,
- a transformer having first and second primary windings and a secondary winding,
- inductor means coupling said first and second transformer primary windings to said output of the rectifier means,
- a pair of first and second switching transistors coupled to said first and second transformer primary windings to control current flow therein,
- a storage capacitor coupled to said first and second transformer primary windings and to the output of the rectifier means,
- a pair of output terminals for connection to a load,
- an LC resonant circuit coupling said transformer secondary winding to said pair of output terminals, and
- a single control circuit responsive to an output voltage at said output terminals and, via a circuit path independent of a load circuit coupled to said output terminals, to a voltage developed across the storage capacitor, thereby to supply complementary switching control signals to respective control electrodes of said first and second switching transistors.
6 more elements
A high frequency push-pull converter power supply comprising:
- an input terminal for connection to a source of supply voltage,
- an output terminal for connection to a load circuit,
- a transformer having first and second primary windings and a secondary winding coupled to said output terminal,
- an energy storage capacitor,
- inductor means coupling said input terminal via at least one of said first and second primary windings of the transformer to said energy storage capacitor,
- first and second switching transistors coupled to said first and second transformer primary windings so as to control current flow therein in a push-pull mode of operation, and
- a control circuit having input means coupled to said load circuit and to said storage capacitor such that the control circuit is responsive to a voltage determined by the load circuit and to a voltage developed across the storage capacitor thereby to supply complementary switching control signals to respective control electrodes of said first and second switching transistors.
4 more elements
Dependencies are inferred from the claim text.