| 摘要 |
A current balance arrangement for the power switching devices of a push-pull converter circuit is disclosed. A dynamic dead band circuit is incorporated into a pulse width modulation current balance and output voltage regulation control circuit to prevent current imbalance from causing saturation of the power transformer core for all operating conditions of the converter including input voltage falling below its rated low-line value, sudden load surges, or turning off of the converter power supply. Whenever the dynamic dead band circuit determines that inverter current flow is being terminated by the dead band interval of the converter clock, a control signal is sent to the pulse width modulation circuitry of the converter to effect inverter current termination prior to initiation of the clock dead band interval in subsequent cycles of converter operation. The invention eliminates the need for providing inverter power switching devices having closely matched electrical characteristics.
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