A circuit breaker includes first and second terminals, first and second vacuum interrupters, an interconnection part, an actuator, an operating rod, and a lever system. The first terminal is connected to a fixed contact of the first vacuum interrupter. The second terminal is electrically connected to a fixed contact of the second vacuum interrupter. The interconnection part is associated with a movable contact of the first and second vacuum interrupters when the circuit breaker is in a closed state. A first end of a first lever arm is coupled to the movable contact, and a second end is coupled to the operating rod. When transitioning from an open to a closed state, the actuator moves the operating rod to move the second end of the first lever arm and the second end of the second lever arm.

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 magnetic electrical switch apparatus includes: a switch assembly that includes: a switch body housing including a stationary contact; a shaft configured to move relative to the switch body housing, the shaft including: a moveable contact; and a first magnet; and a movable support member including a second magnet. The moveable contact and the first magnet are configured to move with the shaft. Moving the movable support member moves the second magnet relative to the first magnet, and a magnetic interaction between the second magnet and the first magnet moves the moveable contact relative to the stationary contact to thereby change a state of the switch assembly.

A system includes a first group of cassettes, each cassette including a first stationary bar, a first plurality of fixed contact members, and a first plurality of movable contact members, each of which is electrically coupled and rotatably connected to the first stationary bar and configured to contact one of the first plurality of fixed contact members. The system includes a second group of cassettes each including a second stationary bar, a second plurality of fixed contact members, and a second plurality of movable contact members, each of which is electrically coupled and rotatably connected to the second stationary bar and configured to contact one of the second plurality of fixed contact members. The system includes at least one operating mechanism to control opening and closing of the movable contact members. The first stationary bar is coupled to the second stationary bar.

A seat occupancy sensor includes: a first sensor group having a plurality of first sensor cells that are arrayed in a front-rear direction of a seat and become conductive as a load is applied thereto; a second sensor group having a plurality of second sensor cells that are arrayed in the front-rear direction, farther on a front side of the seat and closer to an end of the seat in a width direction than the first sensor group, and that become conductive as a load is applied thereto; and an electronic control unit. The electronic control unit determines that someone is sitting on the seat when both of at least one of the first sensor cells and at least one of the second sensor cells become conductive.

Embodiments of negative pressure wound therapy systems and methods are disclosed. In one embodiment, a system includes a wound dressing, negative pressure source, switch, and control circuitry. The switch can include an actuator that toggles states of first and second pairs of contacts in response to a user input. The control circuitry can supply negative pressure with the negative pressure source when the state of the first pair of contacts is a first state and the state of the second pair of contacts is a second state, and the control circuitry can disable supply of negative pressure with the negative pressure source when the state of the first pair of contacts is not the first state or the state of the second pair of contacts is not the second state.

A steering wheel horn assembly having two sections with an annular electrical circuit board member interposed and disposed between the sections and electrically coupled to a power source, an electrical ground, and an electrical horn. Also disposed within the two sections is an annular button membrane with a plurality of deformably resilient horn buttons, wherein each of the plurality of deformably resilient horn buttons have a terminal front surface and a rear surface opposing the terminal front surface and that is disposed adjacent to the annular electrical circuit board member, have a static position along a button translation path projecting through one of the plurality enclosed apertures, and have a depressed position with the rear surface directly coupled to the annular electrical circuit board member and electrically completing a circuit on the annular electrical circuit board member and causing the electrical horn to generate the audible sound.

Switch apparatus (54), designed to detect relative movement between first and second members (60, 62), includes a switch assembly (48) comprising a switch unit (20), a biasing element (50), and an operating member (52). The unit (20) has a conductive housing (22) with first, second, and third electrical pin contacts (36-40) and a shiftable body (46). The body (46) is magnetically correlated with both the element (50) and operating member (52). When the members (60, 62) are close, the operating member (52) maintains the shiftable body (46) in one switch position, whereas when the members (60, 62) are separated, the biasing element (50) magnetically moves body (46) to another switch position, thereby detecting the relative movement).

A steering wheel horn assembly having two sections with an annular electrical circuit board member interposed and disposed between the sections and electrically coupled to a power source, an electrical ground, and an electrical horn. Also disposed within the two sections is an annular button membrane with a plurality of deformably resilient horn buttons, wherein each of the plurality of deformably resilient horn buttons have a terminal front surface and a rear surface opposing the terminal front surface and that is disposed adjacent to the annular electrical circuit board member, have a static position along a button translation path projecting through one of the plurality enclosed apertures, and have a depressed position with the rear surface directly coupled to the annular electrical circuit board member and electrically completing a circuit on the annular electrical circuit board member and causing the electrical horn to generate the audible sound.

Electrical switch contact sets are disclosed. A disclosed example apparatus includes a movable platform having first and second contacts, where the first and second contacts electrically coupled via the movable platform, and a stationary portion having third and fourth contacts, where the movable platform is movable to bring the first and second contacts in contact with the third and fourth contacts, respectively, to simultaneously close a current path of an electrical circuit associated with the first, second, third and fourth contacts.