The electronic equipment and the overvoltage protection network which have the overvoltage protection network and

摘要

PROBLEM TO BE SOLVED: To increase possibility of a device by enabling a continuous operation by one normal power supply, even if the other power supply becomes abnormal.;SOLUTION: Whether a power supply unit 3 itself is a redundant operation is discriminated by a redundancy/non-redundancy operation discriminating circuit 32. If so, a threshold Vpwr for protecting the unit from overvoltage is changed to be controlled by an overvoltage setting and switching circuit 33. Namely, in single operation, the Vpwr is set larger than Vlogic (the threshold of a voltage-monitoring circuit 11) so that the voltage-monitoring circuit 11 on a logical board 1 side is operated first to shut down. An overvoltage protective function is operated on the power supply 3 side the first time, when voltage becomes more excessive than the Vpwr to stop the power supply. When it becomes a redundant operation, the Vpwr is set smaller than the Vlogic to stop the abnormal power supply, and by having the power supplied only by the normal power supply, operation of the device is continued.;COPYRIGHT: (C)2004,JPO