An arc-preventing fast-breaking surge protection device is disclosed. In one of implement, surge protection device includes an arc-preventing assembly consisted of an arc-preventing catapult and an elastic element, comprising a voltage sensitive assembly, a response switch assembly, a thermosensitive element, an inner shell and an outer cover. The voltage sensitive assembly is tightly coupled with the response switch assembly. When the instantaneous surge voltage in circuits causes the voltage sensitive assembly to continuously heat up due to the fault short-circuit current, the response switch assembly causes the arc-prevent assembly to be catapulted and separated by the thermal coupling response of the thermosensitive element, meanwhile the response switch assembly is conceal by the arc-preventing assembly, thus preventing the arc generated when the switch is s catapulted and separated from forming a short-circuit and an overload, thus effectively avoiding fire and explosion hazards and further preventing secondary damage of electronic devices.

A protection device comprises a first planar substrate, a second planar substrate, a heater and a fusible element. The first planar substrate comprises a first surface, and the second planar substrate comprises a second surface facing the first surface. The heater comprises a first heating element and a second heating element in parallel connection, and the first heating element is disposed on the first surface. The fusible element is disposed on the first surface and adjacent to the first and second heating elements, thereby the fusible element is melted by absorbing the heat generated by the first heating element and/or second heating element. The second heating element has a resistance at least twice that of the first heating element.

A reflowable thermal fuse including a fuse body, a conductive composite element disposed within the fuse body, first and second conductive terminals connected to the conductive composite element and extending out of the fuse body, a removable barrier covering a surface of the conductive composite element and in electrical communication with the first and second conductive terminals, and a solvent element disposed on the removable barrier and separated from the conductive composite element by the removable barrier, wherein the removable barrier has a fusing temperature that is greater than a reflow temperature of the reflowable thermal fuse.

A fuse element includes a low-melting-point metal plate, a first high-melting-point metal layer, and a second high-melting-point metal layer. The low-melting-point metal plate has a first main surface, a second main surface, a first side surface, and a second side surface. The first main surface and the second main surface face each other. The first side surface and the second side surface face each other and each connect the first main surface and second main surface. The first high-melting-point metal layer is disposed on the first main surface and second main surface. The second high-melting-point metal layer is disposed on the first side surface and second side surface. The fuse element has a cut-out portion in which at least a portion of the second high-melting-point metal layer is cut out.

The present invention discloses a thermal fuse having dual metal elastic clamps, comprising: an insulating cylindrical tube; a first metal cap, a temperature sensing chamber formed by the first metal cap, the second metal tube and the inner side wall of the middle part of the through hole. The temperature sensing chamber axially arranges a plurality of components in the following sequence: a compressed spring; an insulating supporting pillar; a second metal elastic clamp; a connecting pillar a first metal elastic clamp; an organic temperature sensing body capable of melting when heating. The first metal elastic clamp, the second metal elastic clamp and the connecting pillar forms a movable conductive bridge. The movable conductive bridge slides flexibly in the temperature sensing chamber and has low contacting resistance with the first metal cap and the second metal tube. The above structure can withstand large current and has high reliability.

A switch device capable of safely opening or short-circuiting an electrical circuit in response to an abnormality such as wetting with water or liquid leaking from a battery is provided. The device includes a conductor connected to an external circuit, and a reaction part including a liquid-soluble material which opens the conductor and the external circuit and which dissolves on contacting a liquid entering the device interior to electrically connect the conductor and the external circuit.

A device is provided for switching an electrical circuit for electrical power levels of from 500 watts to 10 megawatts, which has two or more pyrotechnic disconnecting devices, which are connected in series between a terminal point and a load in order to interrupt the electrical circuit. The device also has at least one closing mechanism, wherein the number of closing mechanisms is less than the number of pyrotechnic disconnecting devices and wherein each closing mechanism is arranged in a parallel connection with a single pyrotechnic disconnecting device in order to bridge the one pyrotechnic disconnecting device and thereby close an interrupted electrical circuit.

A protection device comprises a first planar substrate, a second planar substrate, a heating element, a fusible element and an absorbent element. The first substrate comprises a first surface, and the second substrate comprises a second surface facing the first surface. The heating element is disposed on the first surface, and the fusible element is disposed above the heating element. The absorbent element is disposed on the second surface and above the fusible element. When over-current or over-temperature occurs, the heating element heats up to melt and blow the fusible element and the absorbent element absorbs melted metal of the fusible element.

This protective element includes a fuse element having a first end portion and a second end portion, in which current flows from the first end portion toward the second end portion, a protruding member and a recessed member that are positioned opposing one another so as to sandwich a cutoff portion, and a pressing device that imparts an elastic force that shortens the relative distance in a first direction that represents the direction in which the protruding member and the recessed member sandwich the cutoff portion, wherein at least one pair of opposing surfaces of a protruding portion of the protruding member and a recessed portion of the recessed member that intersect the direction of current flow through the fuse element are positioned close to one another when viewed in a plan view from the first direction, and the fuse element is cut at a temperature equal to or higher than the softening temperature of the material that constitutes the fuse element.

A protection element (10) of the present invention has a substrate (11), a first fuse element (12) and a second fuse element (13) connected in series on the substrate (11), a heater (14) connected between the first fuse element (12) and the second fuse element (13), a third upper electrode part (17) connected between the first fuse element (12) and the second fuse element (13) and connected to the heater (14) in series, a first conduction part (18) connected to the third upper electrode part (17) and having a lower resistance value than the heater (14), and a third lower electrode part (19) connected to the first conduction part (18) and configured to be connectable to an external protection circuit.