A quench protection arrangement for a superconducting magnet is disclosed. The arrangement comprises: a superconducting magnet comprising a plurality of magnet sections; a plurality of varistors, wherein each of the plurality of varistors is electrically connected in parallel across a respective one of the plurality of magnet sections; and a heater arrangement electrically connected to the plurality of varistors and configured to apply heat to each of the plurality of magnet sections in response to a change in a voltage across any one or more of the plurality of varistors. A method of protecting a superconducting magnet is also disclosed.

A quench protection arrangement for a superconducting magnet is disclosed. The arrangement comprises: a superconducting magnet comprising a plurality of magnet sections; a plurality of varistors, wherein each of the plurality of varistors is electrically connected in parallel across a respective one of the plurality of magnet sections; and a heater arrangement electrically connected to the plurality of varistors and configured to apply heat to each of the plurality of magnet sections in response to a change in a voltage across any one or more of the plurality of varistors. A method of protecting a superconducting magnet is also disclosed.

A flat spring (100) is disclosed, for use in a surge protection device (SPD) such as a fast activation thermal fuse, to be integrated with a thermal metal oxide varistor (TMOV). The flat spring (100) has a V-shaped protrusion (110) to enable ultra-high short circuit current protection under overvoltage condition.

A flat spring (100) is disclosed, for use in a surge protection device (SPD) such as a fast activation thermal fuse, to be integrated with a thermal metal oxide varistor (TMOV). The flat spring (100) has a V-shaped protrusion (110) to enable ultra-high short circuit current protection under overvoltage condition.

A surge protective device (SPD) circuit system for providing overvoltage protection to an electrical power circuit includes a PCB assembly, an SPD module, and an SPD monitoring system. The PCB assembly selectively mountable on the PCB includes a PCB and a remote signal (RS) PCB contact on the PCB. The SPD module includes an overvoltage clamping element and an RS spring contact including an RS contact portion. When the SPD module is mounted on the PCB and the electrical power circuit is connected to the PCB: the PCB electrically connects the SPD module to the circuit and the overvoltage clamping element provides overvoltage protection to the circuit; the RS contact portion engages the RS PCB contact; the RS spring contact is elastically deflected and persistently loads the RS contact portion against the RS PCB contact; and the RS spring contact is electrically connected to the SPD monitoring system via the RS PCB contact.

A metal oxide varistor (MOV) device including a MOV chip, electrically conductive first and second electrodes disposed on opposite sides of the MOV chip, and electrically conductive first and second leads connected to the first and second electrodes, respectively, wherein the first and second electrodes are formed of a material having a melting point greater than 1100 degrees Celsius.

A metal oxide varistor (MOV) device including a MOV chip, electrically conductive first and second electrodes disposed on opposite sides of the MOV chip, and electrically conductive first and second leads connected to the first and second electrodes, respectively, wherein the first and second electrodes are formed of a material having a melting point greater than 1100 degrees Celsius.

In an embodiment a thermal protection device includes a housing, a varistor partly embedded in the housing, wherein the housing electrically insulates the varistor, and wherein the varistor includes a partly uninsulated contact surface, an inner wall of insulating material arranged adjacent to the contact surface of the varistor, a window in the inner wall configured to allow an electrical connection of the contact surface of the varistor in an operational state of the thermal protection device and a moveable insulation block configured to cover the window in the inner wall to insulate the varistor in a region of the window of the inner wall in a fault state of the thermal protection device.

In an embodiment a thermal protection device includes a housing, a varistor partly embedded in the housing, wherein the housing electrically insulates the varistor, and wherein the varistor includes a partly uninsulated contact surface, an inner wall of insulating material arranged adjacent to the contact surface of the varistor, a window in the inner wall configured to allow an electrical connection of the contact surface of the varistor in an operational state of the thermal protection device and a moveable insulation block configured to cover the window in the inner wall to insulate the varistor in a region of the window of the inner wall in a fault state of the thermal protection device.

A surge protective device (SPD) assembly module includes a polymeric outer enclosure, an SPD module, a first terminal, and a second terminal. The polymeric outer enclosure defines an enclosed, environmentally sealed enclosure chamber. The SPD module is disposed in the enclosure chamber. The SPD module defines an environmentally sealed SPD chamber and includes: first and second electrically conductive electrode members; and a varistor member formed of a varistor material and electrically connected between the first and second electrode members. The varistor member is disposed in the SPD chamber between the first and second electrode members. The first terminal is electrically connected to the first electrode member and extending out from the outer enclosure. The second terminal is electrically connected to the second electrode member and extending out from the outer enclosure.