| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a protective device of power supply unit for welding, capable of more completely protecting a switching element constituting an inverter circuit even if failure occurs in a cooling device. <P>SOLUTION: A control circuit, upon determination of abnormal rotation of a cooling fan, implements inverter stop control based on comparison between a fourth preset temperature d lowered from normally using third preset temperature c and a detected temperature of a temperature sensor. Thus, before a temperature of a switching element itself deviated from the detected temperature of the temperature sensor becomes excessively high, the operation of the element can be stopped. <P>COPYRIGHT: (C)2012,JPO&INPIT |
