A protective element includes an insulating substrate, a plurality of electrodes provided on the insulating substrate, a fuse element electrically connected to any electrode of the plurality of electrodes, and a heat generation element provided on the insulating substrate for heating and fusing the fuse element. The fuse element contains a composite metal material in which a first fusible metal and a second fusible metal are stacked, some of a component of the first fusible metal being dissolved at a joint working temperature, the second fusible metal being lower in melt temperature than the first fusible metal, at least some of a component of the second fusible metal being molten at the joint working temperature.

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.

A protective element includes: at least two electrode portions (main electrodes) supported by an insulating support (insulating substrate); a fuse element that connects the electrode portions; and an operating flux provided on the fuse element. The operating flux has, on a surface thereof, a coating layer that covers the operating flux to prevent the operating flux from flowing.

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 circuit protection system including at least one fuse including a fuse element, at least one inductive heating element operable to heat the fuse element, at least one control module in communication with the inductive heating element, and at least one current detection device coupled to said control module. The control module is configured to operate the inductive heating element and cause the fuse element to open in response to a predetermined current condition.

A fuse control system and method using a defective mode detection, in which an overcurrent protective fuse and a signal fuse capable of performing a function under various conditions in order to protect a circuit are integrated. Thus, it is possible to protect the circuit even in states such as overvoltage, a high temperature, a low temperature, and other dangerous states in addition to an overcurrent state and a short-circuited state. In addition, it is possible to reduce a wide design space and design cost which result from various kinds of fuses being used in series, and to simplify a circuit configuration. Consequently, since circuit resistance is reduced, it is possible to have a positive influence on a battery.

A battery control apparatus for a battery according to the present invention excludes a faulty battery cell from the connection between battery cells and at the same time automatically connects a replacement battery cell to the battery cells when a fault occurs in some of the battery cells, thereby allowing the output voltage of the battery to be kept constant in spite of the faulty battery cell. Further, in a state where a plurality of battery modules are connected in parallel, the battery control apparatus disconnects a battery module including a faulty battery cell during the replacement of the faulty battery cell, thereby preventing the output voltage of the battery from being discontinuous. In addition, a switch used in the battery control apparatus for a battery is a fusible switch including two separate fixed electrodes and one movable electrode.

A protection device and a battery pack are provided, the protection device includes multiple terminal electrodes including a first terminal electrode and a second terminal electrode; a fusible conductor, where a lower surface of the fusible conductor is disposed on the first and second terminal electrodes, and the fusible conductor is supported by the first and second terminal electrodes, and two ends of the fusible conductor are electrically connected to the first and second terminal electrodes, respectively; and a first heat generating element, where one end of the first heat generating element is coupled to another surface of the fusible conductor different to the lower surface, or one end of the first heat generating element is coupled to a surface of any one of the first and second terminal electrodes.

A safety device comprises a first heat dissipation part, a second heat dissipation part and a connecting part. The connecting part is arranged between the first heat dissipation part and the second heat dissipation part, and at least one heat locking hole disposed thereon. The heat locking hole of the connecting part can reduce a diffusion speed of heat of the connecting part, so that the heat is concentrated between the first heat locking hole and the second heat locking hole, and thus the connecting part can be fused in time at a high temperature.

Provided is a fuse device capable of maintaining the insulation performance while using a fuse element having a considerable size to improve rating. The fuse device includes a fuse element 2 and a case 3 for housing the fuse element 2, and the case 3 has a resin portion 4 having a surface to be melted by heat accompanying blowout of the fuse element 2 on at least a part of an inner wall surface 8a facing the inside 8 housing the fuse element 2.