Abstract: A vacuum valve according to embodiments of the present disclosure, comprising: an electrode having a first surface which a hollow part is formed on, which electrode spiral electrode slits which slantingly cross an axial direction are formed on outer circumference of, a conductor fixed on a second surface of the electrode, which second surface is opposite side of the first surface, a contact point having a first concavity which opens to the conductor side, which contact point is fixed on the first surface of the electrode, and a connecting plate whose resistivity is lower than one of the contact point, which connecting plate is disposed inside the first concavity, and connecting plate slits which extend inward from circumference as a starting point are formed on, wherein central axes of the connecting plate slits incline in a rotatory direction of the spiral of the electrode slits.

Abstract: A vacuum valve according to embodiments of the present disclosure, comprising: an electrode having a first surface which a hollow part is formed on, which electrode spiral electrode slits which slantingly cross an axial direction are formed on outer circumference of, a conductor fixed on a second surface of the electrode, which second surface is opposite side of the first surface, a contact point having a first concavity which opens to the conductor side, which contact point is fixed on the first surface of the electrode, and a connecting plate whose resistivity is lower than one of the contact point, which connecting plate is disposed inside the first concavity, and connecting plate slits which extend inward from circumference as a starting point are formed on, wherein central axes of the connecting plate slits incline in a rotatory direction of the spiral of the electrode slits.

Abstract: A direct-current interrupter in an embodiment includes a current-carrying path and a current-interrupting path connected in parallel to the current-carrying path. The current-carrying path includes a first switch and a second switch connected in series and a resistor connected in parallel to the second switch. The first switch has a predetermined first withstand voltage property and switches between conduction and non-conduction of current by using no semiconductor switch. The second switch has a second withstand voltage property lower in withstand voltage property than the first withstand voltage property and switches between conduction and non-conduction of current by using no semiconductor switch. The resistor protects the second switch from voltage to be applied to the second switch. The current-interrupting path includes a semiconductor switch and a current source connected in series and a non-linear resistor connected in parallel to a series connection of the semiconductor switch and the current source.

Abstract: An electrode arrangement of a vacuum circuit breaker for making and breaking electrical connection. The electrode arrangement has: a pair of contact members which are adopted for making contact to and release from each other by relatively moving to and from each other along a predetermined direction; a pair of electrically conductive bars being connected to the above pair of contact members, respectively, for providing electric conduction to the contact members; and a magnetizing device with a magnetic body for generating magnetic field parallel to the predetermined direction between the contact members. The magnetic body is composed of an iron alloy comprising 0.02 to 1.5% by weight of carbon and iron. The iron alloy may further contain at least one of manganese and silicon.