| 摘要 |
PURPOSE:To eliminate the necessity for direct connection or wiring to an electrical equipment and apparatus and, at the same time, to protect the electric equipment and apparatus from bad influences, by detecting the fluctuating difference of a magnetic flux caused by the fluctuating difference of an electric current flowing to the conductor of the electric equipment and apparatus between normal time and abnormal time. CONSTITUTION:When an attachment plug 3 is inserted into a power supply plug socket and an electrical apparatus 1 is actuated, an AC current is made to flow to a power supply conductor 2a and alternating magnetic fluex are produced around the conductor 2a over the whole length. AC signals are induced in a pickup coil 4 by the alternating magnetic fluxes and given to the electromagnetic coil 7 of an electromagnetic relay switch 6 through an amplifier 5. Accordingly, a movable contact 8 is attracted by an contacted with a fixed contact 9a and a lighting element 11 lights. On the other hand, when the fuse of the electrical apparatus 1 blows out and no electric current flows to the conductor 2a and, as a result, an abnormal condition occurs, the magnetism of the electromagnetic coil 7 is erased and the movable contact 8 is released and contacted with another fixed contact 9b, and then, a buzzer 12 sounds an alarm.
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