The invention relates to a space-saving isolating arrester, having for at least two electronic components (EB.sub.1, EB.sub.2) to be monitored, with the electronic components to be monitored being fastened to a carrier (P) using a thermally softenable fixing means, with an energy accumulator (D.sub.1,D.sub.2) being arranged on each of the electronic components which—when a thermally softenable fixing means softens—displaces the associated electronic component substantially parallel to the carrier (P), thereby disconnecting the associated electronic component, and also having a mechanically displaceable display means (ANZ), with the mechanically displaceable display means indicating that one or more of the electronic components to be monitored has been disconnected, and with the mechanically displaceable display means (ANZ) being displaced by a disconnecting electronic component.

The invention relates to a space-saving isolating arrester, having for at least two electronic components (EB.sub.1, EB.sub.2) to be monitored, with the electronic components to be monitored being fastened to a carrier (P) using a thermally softenable fixing means, with an energy accumulator (D.sub.1,D.sub.2) being arranged on each of the electronic components which—when a thermally softenable fixing means softens—displaces the associated electronic component substantially parallel to the carrier (P), thereby disconnecting the associated electronic component, and also having a mechanically displaceable display means (ANZ), with the mechanically displaceable display means indicating that one or more of the electronic components to be monitored has been disconnected, and with the mechanically displaceable display means (ANZ) being displaced by a disconnecting electronic component.

The object of the invention is a device (1) for protecting a component (EB) against thermal overload. The device (1) has an actuating mechanism (B) which is brought into thermal contact with the component to be protected (EB) when in use, and which is capable of activating a switch (S) upon reaching a certain temperature T.sub.switch. The switch (S) can be used both as a disconnection switch and as a short-circuiting switch in relation to the component to be protected (EB), with the switch (S) furthermore having a selection mechanism (A) with which one can choose whether the switch (S) should be used as a disconnection switch or as a short-circuiting switch in relation to the component to be protected (EB).

The object of the invention is a device (1) for protecting a component (EB) against thermal overload. The device (1) has an actuating mechanism (B) which is brought into thermal contact with the component to be protected (EB) when in use, and which is capable of activating a switch (S) upon reaching a certain temperature T.sub.switch. The switch (S) can be used both as a disconnection switch and as a short-circuiting switch in relation to the component to be protected (EB), with the switch (S) furthermore having a selection mechanism (A) with which one can choose whether the switch (S) should be used as a disconnection switch or as a short-circuiting switch in relation to the component to be protected (EB).

The invention relates to a surge detector comprising a transformer comprising a primary winding arranged to receive a fraction of a surge current and a secondary winding magnetically coupled to the primary winding and arranged to output a signal representing the fraction of the surge current. The surge detector further comprises a shunt connection in parallel with the primary winding, wherein the impedance of the shunt connection is lower than the impedance of the primary winding.

Devices and methods related to metal oxide varistor (MOV) having modified edge. In some embodiments, a MOV can include a metal oxide layer having first side and second sides, first and second electrodes implemented on the first and second sides of the metal oxide layer, respectively, with each electrode including a laterally inner portion and an edge portion. The edge portion of at least the first electrode can have a flared profile. In some embodiments, two of such MOVs can be joined to provide a sealed chamber defined by shapes of the first sides of the respective metal oxide layers and enclosing a gas therein, such that the sealed chamber with the gas and the first electrodes of the two MOVs form a gas discharge tube (GDT).

A multi-terminal surge arrester which includes an active part extending along a longitudinal direction of the surge arrester, a first electrode resting against a first end of the active part, and a second electrode resting against a second end of the active part, which second end opposes the first end in the longitudinal direction of the surge arrester. The surge arrester further includes an insulating fixing device mechanically connecting and fixing the first electrode and the second electrode, and an insulating housing arranged around the active part. The active part includes at least two metal-oxide based varistor elements and a further electrode arranged between the at least two varistor elements, which further electrode provides an externally accessible electrical connection. Therein, the surge arrester is adapted for being insulated by surrounding air.

A multi-terminal surge arrester which includes an active part extending along a longitudinal direction of the surge arrester, a first electrode resting against a first end of the active part, and a second electrode resting against a second end of the active part, which second end opposes the first end in the longitudinal direction of the surge arrester. The surge arrester further includes an insulating fixing device mechanically connecting and fixing the first electrode and the second electrode, and an insulating housing arranged around the active part. The active part includes at least two metal-oxide based varistor elements and a further electrode arranged between the at least two varistor elements, which further electrode provides an externally accessible electrical connection. Therein, the surge arrester is adapted for being insulated by surrounding air.

Provided according to embodiments of the invention are varistor ceramic formulations that include zinc oxide (ZnO). In particular, varistor ceramic formulations of the invention may include dopants including an alkali metal compound, an alkaline earth compound, an oxide of boron, an oxide of aluminum, or a combination thereof. Varistor ceramic formulations may also include other metal oxides. Also provided according to embodiments of the invention are varistor ceramic materials formed by sintering a varistor ceramic formulation according to an embodiment of the invention. Further provided are varistors formed from such ceramic materials and methods of making such materials.

The invention concerns a device for protection against transitory overvoltages, comprising: a varistor; a discharge tube; a thermofusible soldering securing a first electrode of the discharge tube and a first electrode of the varistor, the thermofusible soldering being a conductor of electricity and being able to melt beyond a temperature threshold when the varistor or the discharge tube heats up; the second electrode of the varistor being designed to be connected to a first electrical line and the second electrode of the discharge tube being designed to be connected to a second electrical line; a restoring element exerting a restoring force tending to move the first electrode of the varistor away from the first electrode of the discharge tube in order to allow a separation between the first electrode of the varistor and the first electrode of the discharge tube during a melting of the thermofusible soldering.