A switching device comprising first and second body parts and a first operating device for moving the body parts into a closed state. A piezoelectric actuator is coupled to each body part and is operable to move the body parts part away from one another. The switching device may be incorporated into an actuator for operating the vacuum interrupter of a vacuum circuit breaker.

An overcurrent protection device for a circuit to be monitored, includes at least one trigger unit, which is configured for an interruption of the circuit in at least one trigger situation and which comprises at least one conductor section, which is configured for a conduction of a current to be monitored, at least one trigger element, which comprises at least one magnetically and thermally shape-shiftable material and is, in the trigger situation, configured for a thermally-induced and/or magnetically-induced deformation in dependence on a current that flows through the conductor section, and at least one actuation element, which is operatively connected with the trigger element and is configured for a transmission of at least one actuation movement and/or at least one actuation force to at least one interrupter switch.

A low-voltage circuit breaker includes at least one current sensor for determining the magnitude of the electric current of a conductor of the low-voltage circuit breaker; and at least one electromechanical switching unit for connecting and disconnecting at least two electrical contact points. In a first switching position of the movable contact point, two contact points are connected and in a second switching position the contact points are not connected to one another. The circuit breaker further includes at least one electronic switching unit having a semiconductor switching element, electrically conductive in a first switching state and electrically blocking in a second switching state; an electronic tripping unit, connected to the current sensor, the electronic switching unit and the electromechanical switching unit. Further, when current and/or current/time-period limit values of the conductor are exceeded, first the electromechanical switching unit is opened and then the electronic switching unit is blocked.

A low-voltage circuit breaker includes at least one current sensor for determining the magnitude of the electric current of a conductor of the low-voltage circuit breaker; and at least one electromechanical switching unit for connecting and disconnecting at least two electrical contact points. In a first switching position of the movable contact point, two contact points are connected and in a second switching position the contact points are not connected to one another. The circuit breaker further includes at least one electronic switching unit having a semiconductor switching element, electrically conductive in a first switching state and electrically blocking in a second switching state; an electronic tripping unit, connected to the current sensor, the electronic switching unit and the electromechanical switching unit. Further, when current and/or current/time-period limit values of the conductor are exceeded, first the electromechanical switching unit is opened and then the electronic switching unit is blocked.

An electrostatic protection device includes: a first conductive layer, a second conductive layer and a polarization film layer, in which the polarization film layer is disposed between the first conductive layer and the second conductive layer and formed of a piezoelectric material which is capable of deforming when applied with electricity; a conductive cantilever, disposed on the second conductive layer and including a free end; and a charge diffusion layer, disposed at a side of the conductive cantilever away from the polarization film layer, electrically connected with the first conductive layer and spaced apart from the conductive cantilever, in which upon a voltage difference between the first conductive layer and the second conductive layer reaching a predetermined value, the polarization film layer deforms to allow the conductive cantilever to connect with the charge diffusion layer.

An electrostatic protection device (10) includes: a first conductive layer (110), a second conductive layer (140) and a polarization film layer (130), in which the polarization film layer (130) is disposed between the first conductive layer (110) and the second conductive layer (140) and formed of a piezoelectric material which is capable of deforming when applied with electricity; a conductive cantilever (150), disposed on the second conductive layer (140) and including a free end (152); and a charge diffusion layer (170), disposed at a side of the conductive cantilever (150) away from the polarization film layer (130), electrically connected with the first conductive layer (110) and spaced apart from the conductive cantilever (150), in which upon a voltage difference between the first conductive layer (110) and the second conductive layer (140) reaching a predetermined value, the polarization film layer (130) deforms to allow the conductive cantilever (150) to connect with the charge diffusion layer (170). The device provides the conductive cantilever (150) which is in a suspended state in a case where the voltage difference between the first conductive layer (110) and the second conductive layer (140) does not reach the predetermined value, so the first conductive layer (110) and the second conductive layer (140) are disconnected so that the load of the first conductive layer (110) and the second conductive layer (140) are prevented from being influenced.

A switching device comprising first and second body parts and a first operating device for moving the body parts into a closed state. A piezoelectric actuator is coupled to each body part and is operable to move the body parts part away from one another. The switching device may be incorporated into an actuator for operating the vacuum interrupter of a vacuum circuit breaker.

An overcurrent protection device for a circuit to be monitored, includes at least one trigger unit, which is configured for an interruption of the circuit in at least one trigger situation and which comprises at least one conductor section, which is configured for a conduction of a current to be monitored, at least one trigger element, which comprises at least one magnetically and thermally shape-shiftable material and is, in the trigger situation, configured for a thermally-induced and/or magnetically-induced deformation in dependence on a current that flows through the conductor section, and at least one actuation element, which is operatively connected with the trigger element and is configured for a transmission of at least one actuation movement and/or at least one actuation force to at least one interrupter switch.

A switch is disclosed, in particular a power switch, for low voltages. The switch includes mechanically separable contact elements, in abutment when the switch is closed and via which a current to be monitored flows through the switch, an electronic trigger unit, which triggers a respective contact mechanics unit if a current condition is satisfied. In the event of triggering, the contacts are separated and the switch is switched on via the contact mechanics unit. A supply unit is included to extract a first electric energy from the current flowing through the switch to supply the trigger unit with energy. To guarantee energy supply even when switching to a short-circuit, the contact mechanics unit is coupled to a conversion unit, which converts a portion of the mechanical energy to be provided during switching-on into a second electric energy that supplies the trigger unit with electric energy during switching-on.