A switch device includes: an operation unit including a first switch, a second switch, a first resistor, a second resistor, and a first terminal; and a control unit including a second terminal coupled to the first terminal. A series circuit of the first switch and the first resistor and a series circuit of the second switch and the second resistor are coupled between the first terminal and a ground. The control unit monitors a potential of the first terminal which changes in response to on/off of the first and second switches via the second terminal, and determines the operation state of each switch based on the potential. A contact of the first switch is configured of a contact in which a resistance value between contacts at the time of opening and closing changes more sharply as compared with a contact of the second switch.

Provided is a vacuum interrupter capable of improving an axial magnetic field intensity even at a contact portion other than a region of the contact portion corresponding to a region surrounded by an arm portion and a coil portion. In the vacuum interrupter according to the present disclosure, in each coil electrode, a bypass portion has: a second coil portion which extends so as to have an overlap with a corresponding first coil portion and a power feeding portion opposed to the first coil portion, in a circumferential direction; a first arm portion which connects the second coil portion and a ring portion; and a second arm portion which connects the second coil portion and the first coil portion.

According to one embodiment, a Vacuum interrupter includes a pair of electrodes provided such that their electrode opposed surfaces face each other, and an undulating structure provided in at least one of the electrode opposed surfaces. The undulating structure includes one or more projections which project from the electrode opposed surface, and depressions provided so as to be adjacent to the projections, respectively. The projections and the depressions are alternately provided in a direction crossing the electrode opposed surface. In a conducting state in which the electrodes are in contact with each other, the projections are in contact with the opposite electrode opposed surface.

A luminous keyswitch includes a keycap having a light-transparent portion, a baseplate, an up-down mechanism with two ends respectively moveably connected to the keycap and the baseplate, a function sheet disposed on or under the baseplate, and a light source disposed on the function sheet within a vertical projection of the keycap and connected by a copper wire to provide a light illuminating the light-transparent portion. The function sheet includes a flexible upper circuit layer having a first contact point, a flexible spacer layer having a hole, and a flexible lower circuit layer having a second copper contact point, a third copper contact point, a first copper wire connected to the second copper contact point, and a second copper wire connected to the third copper contact point. When the keycap is pressed, the first contact point passes through the hole to electrically connect the second and third copper contact points.

A luminous keyswitch includes a keycap having a light-transparent portion, a baseplate, an up-down mechanism with two ends respectively moveably connected to the keycap and the baseplate, a function sheet disposed on or under the baseplate, and a light source disposed on the function sheet within a vertical projection of the keycap and connected by a copper wire to provide a light illuminating the light-transparent portion. The function sheet includes a flexible upper circuit layer having a first contact point, a flexible spacer layer having a hole, and a flexible lower circuit layer having a second copper contact point, a third copper contact point, a first copper wire connected to the second copper contact point, and a second copper wire connected to the third copper contact point. When the keycap is pressed, the first contact point passes through the hole to electrically connect the second and third copper contact points.

An ultra-fast moving conductor for use with a circuit breaker is provided. The moving conductor includes a hollow outer stem and a removable core. Multiple removable cores are produced for use with the moving conductor for different purposes. The outer stem is produced from annealed copper that must be brazed before the circuit breaker is placed into operation, and a first removable core produced from copper is inserted into the outer stem to provide structural reinforcement to the outer stem during brazing. After brazing is complete, the copper core is removed from the outer stem, and a significantly lighter work hardened aluminum core is inserted into the outer stem. The lightweight aluminum core enables the moving conductor to open the circuit breaker much faster than the copper core would, and the copper core prevents contamination of the brazing furnace that would result from using the aluminum core during brazing.

A system for isolating a fault in a direct current (DC) grid using thermionic arc extinction. The system includes a DC grid that includes a transmission line. The DC grid also includes a plurality of current interrupters disposed on the transmission line. Each of the plurality of current interrupters on the transmission line are electrically coupled to one another in series. At least one of the current interrupters includes a fixed terminal end and a moveable terminal end. Further, at least one of the current interrupters has an arc shield housing at least two arcing contacts. At least one of the arcing contacts comprises a first conducting material that has a first vaporizing point.

A system for isolating a fault in a direct current (DC) grid using thermionic arc extinction. The system includes a DC grid that includes a transmission line. The DC grid also includes a plurality of current interrupters disposed on the transmission line. Each of the plurality of current interrupters on the transmission line are electrically coupled to one another in series. At least one of the current interrupters includes a fixed terminal end and a moveable terminal end. Further, at least one of the current interrupters has an arc shield housing at least two arcing contacts. At least one of the arcing contacts comprises a first conducting material that has a first vaporizing point.

An electrical contact device includes a high electric potential-side contact and a low electric potential-side contact having a lower electric potential than the high electric potential-side contact. The high electric potential-side contact and the low electric potential-side contact are configured to be brought into and out of contact with each other. At least one of the high electric potential-side contact and the low electric potential-side contact is formed of a low-boiling point material whose boiling point is lower than 2562° C. or a mixed material that contains the low-boiling point material.

A touch control keyboard includes a plurality of keycaps, a plurality of touch key parts, a plurality pairs of conductive distributions, a first circuit board, and a second circuit board. An upper part of each keycap includes a touch key part having a coupling capacitor. The touch key parts and the pair of conductive distributions and the first circuit board are electrically connected. The first circuit board detects the coupling capacitors of the touch key parts by using the pair of conductive distributions to generate a first key signal. The second circuit board detects keystrokes of the keycaps to generate a second key signal.