| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a novel resonant circuit in which breakdown in di/dt mode is prevented by lowering the oscillation frequency of a power supply upon occurrence of off-resonance. <P>SOLUTION: A series circuit of a high side switch 2 and a low side switch 3 is connected across a DC power supply 1, a control circuit 10 is connected with the gate terminals of these switches 2 and 3, a series circuit of the primary winding 5 of a transformer 4 insulated between primary and secondary and a resonant capacitor 7 is connected in parallel with the low side switch 3 and the switches 2 and 3 are turned on/off alternately. In such a resonant circuit, inversion of the gate signal of the switches 2 and 3 is forbidden during a period when a current flowing through the switches 2 and 3 is flowing through the body diode of any one of these switches 2 and 3 so that the switch conducting the current is sustained in on state. After the current flowing through the switches 2 and 3 flows completely through the body diodes of the switches 2 and 3, the gate signal of the switches 2 and 3 is inverted. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
