Abstract: A direct-current circuit breaker includes a switching unit inserted in the direct-current line; and a commutation circuit that includes a series circuit including a first current-limiting element and an interrupting unit that forms a current zero point by superimposing a resonance current on a direct current flowing in the direct-current line and interrupts the direct current at the current zero point, that is connected in parallel with the switching unit, and that becomes a flow path for the direct current after the switching unit is opened, wherein current interruption is performed by the interrupting unit after the switching unit is opened.

Abstract: A direct-current circuit breaker includes a switching unit inserted in the direct-current line; and a commutation circuit that includes a series circuit including a first current-limiting element and an interrupting unit that forms a current zero point by superimposing a resonance current on a direct current flowing in the direct-current line and interrupts the direct current at the current zero point, that is connected in parallel with the switching unit, and that becomes a flow path for the direct current after the switching unit is opened, wherein current interruption is performed by the interrupting unit after the switching unit is opened.

Abstract: An each area automatic selection receiver of an emergency radio signal is an emergency broadcast receiver which enables current area code CAC to be updated automatically. This receiver is constituted in such a way that a GPS receiver obtains current position information by use of the satellite positioning system, then, a converter converts the current position information into an area code by use of a conversion table to write the area code into a code memory. For that reason, even though the receiver moves anywhere, contents of the code memory are always updated to an area code of an area of the movement destination automatically. Therefore, emergency broadcast of the area is always capable of being received correctly.

Abstract: A phase control switch apparatus incorporating a phase-based break/make controller (80A, 80B, 80C) for protecting a reactive load such as a transformer (10) from transient surge phenomena taking place upon power-supply breaking/making operation.

Abstract: An each area automatic selection receiver of an emergency radio signal is an emergency broadcast receiver which enables current area code CAC to be updated automatically. This receiver is constituted in such a way that a GPS receiver obtains current position information by use of the satellite positioning system, then, a converter converts the current position information into an area code by use of a conversion table to write the area code into a code memory. For that reason, even though the receiver moves anywhere, contents of the code memory are always updated to an area code of an area of the movement destination automatically. Therefore, emergency broadcast of the area is always capable of being received correctly.