A key entry device including a housing, a keypad array disposed within the housing and including a plurality of keys, a key contact array disposed within the housing below the keypad array and including a plurality of contact pairs, a dome array underlying the keypad array and the key contact array and including a plurality of domes, and a protrusion array underlying the dome array and including a plurality of protrusions, whereby depression of one of the plurality of keys of the keypad array causes a corresponding one of the domes of the dome array to be displaced downwardly and to be deformed by pushing engagement with a corresponding one of the protrusions of the protrusion array into contact with at least one of the contact pairs of the key contact array.

A key entry device including a housing, a keypad array disposed within the housing and including a plurality of keys, a key contact array disposed within the housing below the keypad array and including a plurality of contact pairs, a dome array underlying the keypad array and the key contact array and including a plurality of domes, and a protrusion array underlying the dome array and including a plurality of protrusions, whereby depression of one of the plurality of keys of the keypad array causes a corresponding one of the domes of the dome array to be displaced downwardly and to be deformed by pushing engagement with a corresponding one of the protrusions of the protrusion array into contact with at least one of the contact pairs of the key contact array.

A metal contact member 10 includes a metal sheet 15, which has a plurality of streaky projecting portions extend along each other on a front surface 15A of the metal sheet 15. A rubber switch member 12 includes the metal contact member 10 and a rubber switch body 11 joined to the metal contact member 10.

A system for thermionic arc extinction via anode ion depletion. The system includes a fixed terminal end including at least a fixed conductor containing at least a fixed contact. The system includes a moveable terminal end including at least a moveable conductor containing at least a moveable contact. The system includes a body including an inner compartment, wherein the inner compartment includes at least an arc shield housing at least two arcing contacts, the at least two arcing contacts including at least an anode contact and at least a cathode contact.

Energy regulators which use a bi-metallic strip to open and close electrical contacts are commonly used in household appliances for temperature regulation. This approach however often results in a slow connection and disconnection of the electrical contacts. This can result in arcing which can reduce the life of the switching components and/or cause the contacts to bond together which poses a potential safety risk. Disclosed is a switching blade suitable for use in an energy regulator in which the electrical contacts are connected and disconnected rapidly. Also described is an improvement to the construction of the switching blade whereby the movement of the blade may provide an impact or jolt to separate contacts which may have bonded together.

The present disclosure relates to an electromechanical switching device comprising switching contacts configured to close an electrical circuit, wherein the switching contacts have a first switching contact and a second switching contact, wherein the first switching contact and the second switching contact can be brought into contact in order to close the electrical circuit, wherein at least one of the switching contacts s formed from a plurality of closed bodies which are arranged against one another, and wherein hollow spaces for receiving liquid are arranged between the closed bodies.

Systems and methods for a hack-proof security keyboard are described. In some embodiments, a keyboard module may include a first circuit configured to detect activation of a plurality of keys and a second circuit configured to detect activation of a subset of the plurality of keys, where the second circuit overlies the first circuit. In other embodiments, a method may include detecting an electrical signal received from a secondary membrane of a keyboard, where the keyboard includes a primary membrane configured to detect individual activation of any of a plurality of keys, and where the secondary membrane is configured to output the electrical signal in response to concurrent activation of a subset of the plurality of keys. The method may also include performing a selected action in response to the detection.

A system for thermionic arc extinction via anode ion depletion. The system includes a fixed terminal end including at least a fixed conductor containing at least a fixed contact. The system includes a moveable terminal end including at least a moveable conductor containing at least a moveable contact. The system includes a body including an inner compartment, wherein the inner compartment includes at least an arc shield housing at least two arcing contacts, the at least two arcing contacts including at least an anode contact and at least a cathode contact.

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 thermomagnetic trip assembly includes a thermal trip, a magnetic trip, and first and second actuation levers. The thermal trip includes a bimetal strip that is capable of deforming in order to actuate the first actuation lever. The magnetic trip includes a movable armature, a fixed armature and an electrical conductor. The movable armature is capable of moving in order to actuate the second actuation lever. The electrical conductor and the bimetal strip are electrically connected in series with one another between first and second connection terminals of the trip assembly. The movable armature is connected to the first connection terminal, the fixed armature is connected to the second connection terminal, and the respective contact areas of the fixed armature and of the movable armature are made of electrically conductive materials that exhibit a low degree of mutual weldability.