An activatable thermal fuse includes a first electrical terminal, a second electrical terminal, and an electrically conductive bridge element having a first electric contact with the first electrical terminal and a second electric contact with the second electrical terminal. At least a part of the bridge element is displaceable from a first position in which the first contact is established to a second position in which the first contact is opened, and a thermally sensitive member releases the part when exposed to a predetermined temperature value. An activating element blocks displacement of the part from the first position, in a first position of the activating element, and enables the displacement of the part in a second position of the activating element. A method of manufacturing a printed circuit board, a method of monitoring, and an electronic circuit including the thermal fuse are also provided.

A circuit protection device includes: a housing (102) defining a cavity (130); a metal oxide varistor (110) disposed within the cavity; a movable electrode (122) attached to a first side of the metal oxide varistor by a solder connection (140); an arc shield (114) disposed within the housing on the first side of the metal oxide varistor and adjacent to the movable electrode; and a spring (120) attached to the arc shield, wherein the arc shield is mechanically biased against the movable electrode along a surface direction parallel to the first side when the spring is in a compressed state. The device is easy to assemble in lower cost and provides fast response to overheating caused by a fault condition.

A thermal limiter system for an electric motor includes a thermal limiter fuse having a hollow contact element anchored by solder to at least one of first and second terminals of the fuse. A coaxial spring element causes the hollow contact element to slidably release and separate from one of the first and second terminals due to overheating of the solder that is not caused by a flow of electrical current. The system also includes stator mounting blocks and a stator cooling jacket for a motor to be thermally protected.

A surge protective device (SPD) module includes a module housing, first and second module electrical terminals mounted on the module housing, a gas discharge tube (GDT) mounted in the module housing, and a fail-safe mechanism mounted in the module housing. The GDT includes a first GDT terminal electrically connected to the first module electrical terminal and a second GDT terminal electrically connected to the second module electrical terminal. The fail-safe mechanism includes: an electrically conductive shorting bar positioned in a ready position and repositionable to a shorting position; a biasing member applying a biasing load to the shorting bar to direct the shorting bar from the ready position to the shorting position; and a meltable member. The meltable member maintains the shorting bar in the ready position and melts in response to a prescribed temperature to permit the shorting bar to transition from the ready position to the shorting position under the biasing load of the biasing member. In the shorting position, the shorting bar forms an electrical short circuit between the first and second GDT terminals to bypass the GDT.

A fuse element for an electric circuit, arranged on a circuit board of the electric circuit, has a surface area for fastening and establishing an electric contact on the circuit board, a first deforming area adjacent the surface area, a second deforming area connected to the first deforming area via a central area, the second deforming area including a contact area that abuts the circuit board, and a hook-shaped element insertable into an opening adjacent the contact area, the hook-shaped element is insertable into the opening by elastic deformation of the fuse element in the direction of the circuit board and, after insertion of the hook-shaped element into the opening and positive holding of the hook-shaped element on a lower surface of the circuit board, the first and second deforming areas exert an elastic force on the surface area in the direction away from the circuit board.

A surge protective device (SPD) module includes a module housing, first and second module electrical terminals mounted on the module housing, an overvoltage clamping element electrically connected between the first and second module electrical terminals, and a thermal disconnector mechanism. The thermal disconnector mechanism is positioned in a ready configuration, wherein the overvoltage clamping element is electrically connected with the second module electrical terminal. The thermal disconnector mechanism is repositionable to electrically disconnect the overvoltage clamping element from the second module electrical terminal. The thermal disconnector mechanism includes: an electrode electrically connected to the overvoltage clamping element; a disconnect spring elastically deflected and electrically connected to the electrode in the ready configuration; a solder securing the disconnect spring in electrical connection with the electrode in the ready configuration; and a heat sink member thermally interposed between the electrode and the solder, the heat sink member having a thermal capacity. The solder is meltable in response to overheating of the overvoltage clamping element. The disconnect spring is configured to electrically disconnect the overvoltage clamping element from the second module electrical terminal when the solder is melted. The thermal capacity of the heat sink member buffers and dissipates heat from the overvoltage clamping element to prevent the solder from melting in response to at least some surge currents through the SPD module.

A varistor component and a method for securing a varistor component are disclosed. In an embodiment a varistor component includes a first external contact, a second external contact, a varistor electrically connected to the first external contact, a path between the varistor and the second external contact and an active releasing device having a shutter and a heat sensitive element, wherein, under abnormal operation conditions, the heat sensitive element releases the shutter, and the shutter moves along a straight line and closes the path between the varistor and the second external contact.

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 base of a surge protector, the surge protector comprising a function rotating member (3), and the function rotating member (3) having a remote linkage rod contact wall (3D) and a remote linkage notching (3H), and the base comprising a remote device, and the remote device having at least one remote linkage rod (9), and when the function rotating member (3) is situated at the first position, the remote linkage rod (9) is pressed down by the remote linkage rod contact wall (3D), and when the function rotating member (3) is rotated from the first position to the second position, the function rotating member (3) is rotated from the remote linkage rod contact wall (3D) to the remote linkage notching (3H) with respect to the point of action of the remote linkage rod (9) to release the remote linkage rod (9).