| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a low cost current resonance type converter with a relatively simple circuit configuration. <P>SOLUTION: A converter includes a main circuit 10 and a control circuit 20 for inputting a control signal S20 to the main circuit 10. The main circuit 10 converts a DC input voltage Vin into an AC voltage and converts the AC voltage into a DC output voltage Vo by making a switching element, which performs on/off operation by the control signal S20 having a switching frequency fs, perform a soft switching operation by use of an LC resonance operation. The control circuit 20 includes: output voltage detection means 31 for detecting the startup output voltage Vo and obtaining a detection result; frequency determining means 32 for determining the frequency fs for commencement of a soft start based on a characteristic of the output voltage of the converter vs. the switching frequency and the detection result; and frequency control means 22 for controlling a startup of the switching element by the control signal S20 that gradually decreases the frequency fs after commencing the soft start at the determined frequency fs. <P>COPYRIGHT: (C)2012,JPO&INPIT |
