A power distribution unit includes a housing having walls defining a main cavity provided at a first side and a secondary cavity provided at a second side. The power distribution unit includes a main contactor received in the main cavity having first and second fixed contacts and a movable contact movable between a mated position and an unmated position to electrically connect the first and second fixed contacts. The main contactor includes a coil assembly energized to move the movable contact. The power distribution unit includes a pre-charge assembly received in the secondary cavity having a control circuit board, a pre-charge resistor coupled to the control circuit board, and a pre-charge switch coupled to the control circuit board. The power distribution unit includes a cover coupled to the housing to enclose the pre-charge assembly in the secondary cavity.

A contactor (1) comprising a first contact member (3) fixed and connected to a first conductor (5) of an electrical circuit; a second contact member (7) connected to a second conductor (9) of the electrical circuit by a connector (11); wherein the second contact member moves between a break position, in which the first and second contact members are out of contact, and a make position, in which the first and second contact members are in contact; an actuator assembly (15) coupled to the second contact member such that actuation of the actuator assembly translates into movement of the second contact member; an electromagnetic arrangement comprising an electromagnetic coil (17) and at least a part of the actuator assembly, wherein, when the coil is energised, the coil generates a magnetic field and thereby the actuation assembly is caused to move under the influence of the magnetic field, which in turn causes the second contact member to move; a hermetically sealable enclosure (2); wherein the first and second contact members, the connector, and the actuation assembly are inside the enclosure; and the coil is outside the enclosure.

In an embodiment a switching device includes at least one stationary contact, a movable contact, an armature, a first permanent magnet, a second permanent magnet and a magnetic switch, wherein the movable contact is movable by the armature, wherein the first permanent magnet is attached to the armature, and wherein the second permanent magnet is arranged in a fixed position relative to the magnetic switch.

In an embodiment, a switching device includes at least one stationary contact, a movable contact, an armature, a permanent magnet and a magnetically-operated switch, wherein the movable contact is movable by the armature, wherein the permanent magnet is attached to the armature, and wherein the magnetically-operated switch is a Hall switch.

In an embodiment a switching device includes at least two stationary contacts and one movable contact in a switching chamber, wherein the switching chamber has a switching chamber wall, wherein each of the stationary contacts projects into the switching chamber through a respective opening in the switching chamber wall, and wherein, on an inner side of the switching chamber that faces the movable contact, a continuous surface region occluded by the stationary contacts is located between the openings in the switching chamber wall.

Use of a hydrogen tank of a vehicle such as an aircraft for protecting at least one electrical connection device linked to at least one electrical device. At least one connection device is placed in a tank or in a sealed enclosure supplied with hydrogen by a tank or by any other source of hydrogen supply of the vehicle. The use of a tank that already exists in the vehicle makes it possible to avoid having to use specific chambers incorporated in a complex manner with the connection device.

In an embodiment a switching device includes at least one stationary contact in a switching chamber containing a gas comprising H.sub.2 and one movable contact in the switching chamber, wherein the switching chamber has a switching chamber wall and a switching chamber base, and wherein the switching chamber at least partially comprises a polymer material configured to release hydrogen when heated.

Electrical switching devices are disclosed that have pressure relief mechanisms to allow for the release of internal pressure within the switching device housing. The pressure within the housing can be caused by different events with one such event being internal arcing within the housing caused during operation of the housing's internal components. Is some cases the arcing can be caused during separation of the switching device contacts. The pressure relief mechanism allows for the high pressure to pass from the housing in a more controlled matter to minimize or prevent high pressure breach or rupture of the switching device housing. The pressure relief mechanisms are particularly applicable to switching devices with hermetically sealed housings. Many different pressure relief mechanisms can be used including rupture disks or engineered weak points in the switching device housing.

A switching device is disclosed. In an embodiment a switching device includes at least one stationary contact and a movable contact in a switching chamber configured to contain a gas containing H.sub.2, wherein the movable contact is movable by a magnetic armature with a shaft, wherein the shaft projects through an opening in a yoke which is part of a magnetic circuit, and wherein a liner composed of a plastic is arranged in the opening of the yoke, the liner configured to guide the shaft.

An electromagnetic relay includes a mobile component movable at time of energization and de-energization of a coil, and a fixed component immovable at the time of energization and de-energization of the coil. A damping space is provided between the mobile component and the fixed component and changes in volume with the movement of the mobile component. A gap provided between the mobile component and the fixed component serves as a passage that allows gas to flow into or out of the damping space when the damping space changes in volume. A size of the gap is set such that a pressure is generated in the damping space to cause a damping force acting on the mobile component when the damping space changes in volume.