| 摘要 |
<p>PURPOSE: To operate a breaker disposed in a power system based on optical output by disposing a polarizer and an analyzer with a relative angle in the polarization direction of the polarizer to the analyzer having such a positional relation as optical output becomes zero when the Faraday-rotation angle of a magneto-optical effect element is saturated, and by applying DC magnetic field where the Faraday-rotation angle is saturated. CONSTITUTION: The first polarizer 210a and the first analyzer 230a are disposed at a relative angle in the polarization direction of the polarizer 210a to the analyzer 230a onto such a position as optical output becomes zero when the Faraday-rotation angle of the first magneto-optical effect element 220a is saturated, and the second optical path parallel to it is provided. A DC magnetic field which is in a saturated region is applied with magnetic field intensity generated by an ordinary load current which is flowing. If over-current flows through a power system, a magnetic field generated by the optical path becomes large, and the Faraday-rotation angle of the magneto-optical effect element 220a becomes large, thus operating the breaker. It is thus possible to switch the breaker according to the presence of over-current instantaneously and thereby to improve the reliability.</p> |
