Electric circuit apparatus

摘要

Circuit elements of surface-mounting type such as MOSFETs etc. are mounted on a circuit board by soldering. The circuit board is retained slantingly by a base so that any one of the MOSFET falls out by its self-weight when the solder melts due to an abnormal heat generation of the MOSFET. The falling of the MOSFET is stopped by a stopper member, and then the MOSFET becomes in an electrically open state and retained at the stopped position in consequence of the subsequent cooling of the solder. Accordingly, even if one or more of the MOSFETs cause the abnormal heat generation, the continuous heat generation of the MOSFET is stopped and also the other circuit elements are prevented from being short-circuited.