| 摘要 |
A resonant power converter holds energy within the circuit for a variable period to provide fixed-frequency, zero-voltage switching power conversion. A first switch alternately connects and disconnects a DC voltage source to one side of the primary winding of the transformer of a power converter. A second switch is connected between the other side of the primary winding and ground. A switch controller is responsive to the difference between a reference voltage and the voltage level present at the output of the circuit associated with the secondary winding of the transformer. Energy is added to the circuit while the first and second switches are closed. The first switch is then opened and energy is held in the circuit for a variable period of time to delay the beginning of resonance. Finally, both switches are opened and the energy within the circuit resonates. The energy holding period is adjusted as necessary to maintain a fixed frequency with varying loads. Accordingly, the switch controller is configured to open and close the first and second switches to maintain fixed-frequency operation of the power converter and switching of the second switch under zero-voltage conditions and in the presence of varying loads.
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