| 摘要 |
PURPOSE: To measure wear precisely and easily at a low cost by providing a microprocessor which is equipped with a timing circuit, a square circuit and an integrator, and a circuit which forms an image of a current value passing a breaker. CONSTITUTION: The occurrence of a current passing a coil B is applied to a microprocessorμP, and theμP starts timing. A timing circuit in theμP operates an integrator in theμP after the lapse of a waiting period equivalent to the mechanical time of a breaker, being previously measured data. Subsequently, a current measuring device TCS forms the image of a current value passing a breaker pole 1, executes the square of the image, and applies the same to the integrator. Next, integration is executed for predetermined duration which is larger than the maximum arc time of the breaker, being previously measured data, and the result of the integration is applied to an adder. TheμP computes the ware rate of the breaker, and drives threshold value devices DS1, DS2.
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