The invention relates to an arrangement for non-reversible detection and display of electrical overcurrents or current limit values by means of a pre-finished conductor. The conductor according to the invention has at least two conductor sections, spaced apart from each other and extending parallel to each other, which are designed for current to flow through in the same direction. At least one of the parallel conductor sections has a protrusion, a nose, or similar blocking element, which limits the path of movement of a mechanical display or switching element, such that the electromagnetic force acting on the parallel conductor sections during the flow of current transitions the blocking element into a release position in respect of the path of movement of the mechanical display or switching element. Such an arrangement can be used particularly advantageously as a prior damage indicator in surge arresters.

An electric machine includes a plurality of conductive tracks defining an electric power circuit, to provide current for electronic power components, a printed circuit board which mounts the conductive tracks, an enclosure which defines a housing for the printed circuit board and has a dissipative wall, a heat-conductive filler interposed between the printed circuit board and the enclosure, an elastic device acting on the printed circuit board to press it against the dissipative wall, a conductive element held in position by at least one heat-sensitive joint and disposed to connect a first track and a second track to close the electric power circuit. The elastic device includes an elastic element pressed against the conductive element to apply a force on the heat-sensitive joint and the heat-sensitive joint is configured to break if subjected to a temperature higher than a predetermined threshold temperature to open the electric power circuit.

The invention relates to an overvoltage protection arrangement having: a plurality of planar varistors 2, 21, 22, which are arranged on a first side of a supporting plate 7; at least one gas arrester 10; and at least one thermal disconnection device, which is in close thermal contact with at least one of the varistors. The aforementioned components are surrounded by an outer housing 1, and electrical connection means 6, 61 for soldering to a printed circuit board are also provided on the second side of the supporting plate. The varistors 2, 21, 22 have a parallel stack arrangement, which is delimited on each of two opposing sides by an insulating partition wall 3, 31 which can be attached to the supporting plate. Each partition wall has at least one opening for a varistor terminal (62), each varistor terminal being connected to a thermal disconnection device, which in turn comprises a spring-loaded disconnecting lever (80), the respective disconnecting lever being connected at its first end to the respective varistor terminal by a soldered connection (18) and wherein its second end merges into one of the electrical terminals 6, 61 and penetrates through the supporting plate 7. The thermal disconnection device also has an insulating slide 4, whose free end acts on the disconnecting lever (80), wherein the slide runs in recesses in the respective partition wall 3, 31, and a change in the position of the slide can be seen by means of a viewing opening 8 in the outer housing 1.

A fuse element comprises a low melting point metal layer, a first high melting point metal layer having a higher melting point than a melting point of the low melting point metal layer, and a restricting portion including a high melting point material having a higher melting point than a melting point of the low melting point metal layer and configured to restrict flow of the low melting point metal or deformation of a layered body constituted by the first high melting point metal layer and the low melting point metal layer.

The invention relates to a disconnection and switch-over device for overvoltage protection, particularly for DC systems, comprising at least one arresting element, and a thermal cut-off point incorporated into the electrical interconnect path of the arresting element, the thermal cut-off point comprising a movable mechanically prestressed conductor element that moves from a first position to a second position in the event of a cut-off, and when the second position is reached, an electrical switch-over to a safety device is generated, and the thermal cut-off point is formed by the movable conductor element and a stationary contact element, the movable conductor element being attached to the stationary contact element by a thermally releasable means. According to the invention, a completely electrical cut-off of the arresting element regarding the interconnect path only occurs when the movable conductor element has gone beyond the second position and has reached a third position, the safety device being arranged in series with the arresting element and the movable conductor element being designed as a wiper or sliding contact in relation to the second position, the second position being created by a bypass end point.

A novel temperature-triggered fuse device is configured to be activated at a designer-specified ambient temperature by utilizing wetting force among a pair of wetting material bays and a solder bridge or a solder ball. The solder bridge or the solder ball is typically positioned on top of the pair of wetting material bays separated by an electrically-insulated gap. Preferably, the wetting material bays are at least partly made of gold, nickel, or other elements suitable for generating an increased wetting force to the solder bridge or the solder ball upon increases in ambient temperature. The novel temperature-triggered fuse device can be integrated into various types of integrated circuits (IC's), or can function as a discrete fuse connected to one or more electronic components for robust protection from power surges and/or thermal runaway-related device malfunctions, meltdowns, or explosions. Various methods of producing the temperature-triggered fuse device are also disclosed herein.

A thermal fuse for an electrical circuit is described, with a contact arm by way of which two electrical conductors are electrically conductively connected to each other, wherein the connection of the contact arm to at least one of the two conductors is a soldered joint, which loses its strength when a activation temperature of the fuse is reached. In accordance with this disclosure a permanent magnet is provided, which generates a magnetic force, which lifts the contact arm from at least one of the two conductors as soon as the soldered joint loses its strength.

The invention relates to a protection device for use in an electrical circuit of an electric machine, particularly an electric motor, having a holding device which is designed to receive an hold power supply devices for feeding the electrical current, the holding device being made of a first material with a first melting temperature T1, and temperature protection device, which is designed to protect the electrical circuit from an overtemperature and which is made of a second material with a second melting temperature T2, wherein the first material and the second material are selected, and/or the temperature protection device is arranged, in such a manner that the electrical circuit is automatically interrupted when at least one of the melting temperatures T1, T2 is reached, wherein the ratio of the first melting temperature T1 to the second melting temperature T2 is in range of greater than 1.2 to equal to 1.50. The invention also relates to an electrical drive arrangement having such a protection device.

Embodiments described herein relate generally to a current interrupt device (CID) including a frangible bulb that is configured to be thermally triggered. In some embodiments, the CID includes a breaking contact electrically coupled to a fixed contact and held in electrical contact by the frangible bulb. In some embodiments, the frangible bulb is configured to break at a temperature threshold. In some embodiments, the breaking contact is configured to bend, rotate and/or otherwise deform about a hinge point in order to become electrically disconnected from the fixed contact when the frangible bulb breaks. In some embodiments, opening the electrical circuit between the breaking contact and the fixed contact may prevent overcharging, overvoltage conditions, overcurrent conditions, thermal runaway, and/or other catastrophic failure events.

A method for increasing the protection range of a thermal fuse, which includes the following steps: disposing the thermal fuse on a circuit board including a circuit loop, a first heat generating element and a second heat generating element; the second heat generating element is electrically connected to the circuit loop; electrically connecting the first heat generating element to the circuit loop; and disposing the heat conducting material on the circuit loop and making the heat conducting material cover the thermal fuse, the first heat generating element and the second heat generating element.