Patent ID: 7881082
Filing Date: 2011-02-01
Classification: H02M,Y02B

Abstract:
1. A power conversion apparatus, comprising: a series circuit including a first switching element and a second switching element, the series circuit being connected to a DC power source in parallel; a resonant circuit including a capacitor and a primary winding of a transformer, the resonant circuit being connected to one of the first and second switching elements in parallel; an intermittent signal generator configured to generate an intermittent signal of triggering an intermittent operation according to a state of a load connected to a secondary winding of the transformer; a controller configured to drive the first and second switching elements during a steady period and to control the start and stop of a switching operation of the first and second switching elements according to the intermittent signal from the intermittent signal generator during a suspension period in which the switching operation of the first and second switching elements is suspended according to the intermittent signal from the intermittent signal generator; a current detector configured to detect a resonant current passing through the resonant circuit; and a timing generator configured to generate a timing signal when the resonant current detected by the current detector satisfies a resonant condition, wherein, after the switching operation of the first and second switching elements is suspended according to the intermittent signal from the intermittent signal generator, the controller resumes the switching operation in response to the timing signal from the timing generator, during the suspension period, the controller keeps one of the first and second switching elements in an ON state and the other in an OFF-state, the timing generator generates the timing signal when a positive period is detected in the resonant current passing through the ON-state one of the first and second switching elements during the suspension period, and, in response to the timing signal from the timing generator, the controller turns on the OFF-state one of the first and second switching elements and off the ON-state one.