Power line switch device with piezo-electric actuation

摘要

The invention provides a power line switch device (1) for disconnecting an electric power line (2) in response to a control signal (CS), e.g. to enable remote breaking of electric power supply to a consumer connected to an electric supply net. The switch device (1) includes a power switch for connecting or breaking connection of an electric power line. A switch member serving to switch the power switch between "on" and "off" is actuated by a piezo-electric motor (5) in response to the control signal (CS). A piezo-electric motor can be implemented immune to magnetic fields and is thus suited to provide mechanical energy to reliably drive a power switch in an environment where application of a strong magnetic field may be used to disturb the function of such switch. In preferred embodiments the piezo-electric motor actuates the switch member via a mechanical coupling arrangement (7). This arrangement (7) serves to convert a slow movement provided by the plezo-electric motor (5) to a snap-like movement of the switch member such that contact members (8, 9) are quickly brought in or our of contact thereby eliminating sparks between the contact members (8, 9). Preferably the actuation of the switch member (4) Involves a plurality of repeated movements of the piezo-electric motor (5).