Abstract: Half-bridge
circuit is taken as example, the physical essential of current
pulse front edge and back edge in PWM of PFM converter is
analyzed. The appearance of varying current-source or
transformation from voltage-source into current-source in
primary of converter is necessary condition for forming front
and back edges. Through synchronously varying of primary current
and secondary current, and current shifting between two
secondary windings in constant magnetic condition, transformation
of basic stages is realized.
Key words: Welding Inverter Pulse edge Constant magnetic Current shifting
Manuscript received on
December 3, 1996; revised manuscript December 23, 1996
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