| 摘要 |
PROBLEM TO BE SOLVED: To provide an overcurrent checking device enabling minimization of checking influence on an electric line whose overcurrent is the object of checking, and to provide a circuit protecting device enabling minimization of protection influence on an electric line to which an electric machinery and apparatus that are the objects of protection are connected. SOLUTION: The overcurrent checking device 1 is provided with a magnetic field generating means 11 connected to the electric line 52, which generates magnetic field when electric current flows the electric line 52, a magnetic field detecting means 12 disposed near the magnetic field generating means 11, which detects the magnetic field generated by the magnetic field generating means 11, and an overcurrent detecting means 13 connected to the magnetic field detecting means 12, which detects output of the magnetic field detecting means 12. The circuit protecting device 2 is provided with the overcurrent checking device 1, a breaking circuit 14 connected to the electric line 52 to which the electric machinery and apparatus 41 is connected, and a driving means 15 connected to the overcurrent detecting means 13 in the overcurrent checking device 1, which drives the breaking circuit 14 when the output of the magnetic field detecting means 12, which is detected by the overcurrent detecting means 13, is larger than a prescribed value.
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