PURPOSE: To obtain a system for preventing a fault in a device from affecting other devices, by driving a self-holding relay by a fuse blowout alarm and the output voltage of a power source panel.
CONSTITUTION: An alarm fuse 3 is provided at the power input part of a device. The fuse is adapted to blow out in the event of current above a rating and give an alarm upon blowing out. A power source 4 is provided to generate different voltages required in the device and keep the output voltage for a period longer than required for operating a relay when power supply is stopped. When the alarm fuse 3 gives an alarm, a self-holding relay 5 continues to give an alarm until said alarm fuse 3 is replaced with new one and the output voltage of the power source 4 returns to the regular value. Further, a non-holding relay 6 which is provided to give an alarm when the voltage output of the power source stops and the self-holding relay 5 is not operated.
MIYAJIMA YASUO
IWATANI AKIHIKO
KONO OSAMU
NIPPON ELECTRIC ENG
NEC SHIZUOKA LTD