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US 2004/0105280 A1Published application
Method and apparatus for controlling a DC-DC converter
AssigneeFuji Electric Co., Ltd.
InventorAkihiro Odaka
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AssigneeFuji Electric Co., Ltd.
InventorAkihiro Odaka
Estimating the term…
A method and apparatus for controlling a DC-DC converter is provided that facilitates preventing a switching frequency from increasing under a light load condition even when the exciting inductance of the transformer in the DC-DC converter is high, thereby improving the conversion efficiency of the DC-DC converter. A mechanism is provided to change the switching frequency of the switching devices and to change the on-off ratio of the switching devices. The on-off ratio is changed in response to the output voltage and the switching frequency is changed in response to the input voltage supplied by the DC power supply. Alternatively, the switching frequency is changed while the on-off ratio is fixed at a certain value, and the on-off ratio is changed while the switching frequency is fixed at a predetermined value after the switching frequency has reached the predetermined value, thereby preventing the switching frequency from exceeding the predetermined value.
A method of controlling a DC-DC converter including a first series circuit including two switching devices connected between a positive terminal and a negative terminal of a DC power supply that supplies a DC input voltage, and a second series circuit including one or more capacitors and a primary winding of a transformer connected to one of the switching devices, the DC-DC converter switching on and off the switching devices, whereby to generate positive and negative voltages across a secondary winding of the transformer, and the DC-DC converter conducting half-wave rectification or full-wave rectification of the positive and negative voltages generated across the secondary winding of the transformer, thereby to obtain a DC output voltage, comprising:
A DC-DC converter comprising:
Dependencies are inferred from the claim text.