| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress the occurrence of recovery of a freewheel diode. <P>SOLUTION: Since a transformer 63 is inserted on a primary side of transformers 41 and 42, even when NMOSs 31, 32, 33, and 34 are turned on, an input voltage Vin is instantaneously applied to the transformer 63 to generate no voltage across primary windings 41a and 42a of the transformers 41 and 42. A voltage is not applied across a freewheel diode 55 accordingly. A regenerative current I55 flowing through the freewheel diode 55 gradually reduces from an output current Io to 0A to generate a voltage between both electrodes of the transformers 41 and 42. The voltage resonates with an exciting inductance 63c of the transformer 63 and with a capacitance having a value of conversion of a value C56 of a capacitance 56 to the primary side of the transformers 41 and 42, to slow a voltage change per unit time (dV/dt) and complicate the occurrence of recovery of the freewheel diode 55. <P>COPYRIGHT: (C)2012,JPO&INPIT |
