A protective circuit (1A) is provided with: a protective element (10A): a plurality or secondary battery cells (20), (20), . . . ; an external positive electrode terminal (30a) and an external negative electrode terminal (30b); an auxiliary power supply (40); a first controlling dev ice (50): and a switch (60). The protective element (10A) includes: a first fusible conductor (15) of which the two ends are connected to a first terminal (11) and a second terminal (12): and a heat generating body (16) disposed in a first energizing path (P1.sub.A) between a third terminal (13) and a fourth terminal (14). The auxiliary power supply (40) is provided electrically independently of the plurality of secondary battery cells (20), (20), . . . . In this protective circuit (1A), a signal from the first controlling device (50) causes the switch (60) to switch in such a way as to conduct electricity, thus causing the heat generating body (16) of the protective element (10A) to generate heat which fuses the first fusible conductor (15), thereby isolating the plurality of secondary battery cells (20), (20), . . . from the external negative electrode terminal (30b).

A protective circuit (1A) is provided with: a protective element (10A): a plurality or secondary battery cells (20), (20), . . . ; an external positive electrode terminal (30a) and an external negative electrode terminal (30b); an auxiliary power supply (40); a first controlling dev ice (50): and a switch (60). The protective element (10A) includes: a first fusible conductor (15) of which the two ends are connected to a first terminal (11) and a second terminal (12): and a heat generating body (16) disposed in a first energizing path (P1.sub.A) between a third terminal (13) and a fourth terminal (14). The auxiliary power supply (40) is provided electrically independently of the plurality of secondary battery cells (20), (20), . . . . In this protective circuit (1A), a signal from the first controlling device (50) causes the switch (60) to switch in such a way as to conduct electricity, thus causing the heat generating body (16) of the protective element (10A) to generate heat which fuses the first fusible conductor (15), thereby isolating the plurality of secondary battery cells (20), (20), . . . from the external negative electrode terminal (30b).

A protective element includes a fuse element, a movable member, a concave member, and a press. The fuse member includes, a first end, a second end, and a cut part positioned between the first end and the second end. The fuse element is energized in a first direction from the first end to the second end. The movable member and the concave member are disposed facing each other such that the cut part is interposed therebetween. The press applies a force to the movable member in a pressing direction in which a distance between the movable member and the concave member shortens. At a temperature at or above a softening temperature of the fuse element, the cut part is cut by the force of the press.

A detection circuit includes a first transistor coupled to a gate of a high power transistor, a second transistor whose source is coupled to a drain of the first transistor, a first voltage divider coupled to a source of the first transistor, and a second voltage divider coupled to the source of the second transistor. The first transistor is configured to generate a first transistor output voltage representative of a gate voltage of the high power transistor shifted based on a first gate-to-source voltage of the first transistor. The second transistor is configured to generate a second gate-to-source voltage substantially equal to the first gate-to-source voltage. The first divider is configured to divide the first transistor output voltage by a first factor. The second divider is configured to divide the second gate-to-source voltage by a second factor correlated with the first factor.

The invention relates to a space-saving isolating arrester, having for at least two electronic components (EB.sub.1, EB.sub.2) to be monitored, with the electronic components to be monitored being fastened to a carrier (P) using a thermally softenable fixing means, with an energy accumulator (D.sub.1,D.sub.2) being arranged on each of the electronic components which—when a thermally softenable fixing means softens—displaces the associated electronic component substantially parallel to the carrier (P), thereby disconnecting the associated electronic component, and also having a mechanically displaceable display means (ANZ), with the mechanically displaceable display means indicating that one or more of the electronic components to be monitored has been disconnected, and with the mechanically displaceable display means (ANZ) being displaced by a disconnecting electronic component.

A temperature-sensitive pellet type thermal fuse having a cylindrical metal case (10) with one end electrically connected to a first lead (L1) and a second lead (L2) installed on the other end via an insulating bushing (50). A temperature-sensitive pellet (30) on a spring (13) is in an inner space (S1) of the case (10). A switch terminal (40) has an upper surface (42) electrically connected to the second lead (L2) by an elastic force of the spring (13). A contact terminal piece (41) extends from the upper surface (42) to contact the inner wall surface (11) of the case 10. An activating member operates when the temperature-sensitive pellet (30) is reduced in height to a predetermined level or less, and releases contact between the contact terminal piece (41) and the case (10) to cut off an electrical connection between the first lead (L1) and the second lead (L2).

The object of the invention is a device (1) for protecting a component (EB) against thermal overload. The device (1) has an actuating mechanism (B) which is brought into thermal contact with the component to be protected (EB) when in use, and which is capable of activating a switch (S) upon reaching a certain temperature T.sub.switch. The switch (S) can be used both as a disconnection switch and as a short-circuiting switch in relation to the component to be protected (EB), with the switch (S) furthermore having a selection mechanism (A) with which one can choose whether the switch (S) should be used as a disconnection switch or as a short-circuiting switch in relation to the component to be protected (EB).

The object of the invention is a device (1) for protecting a component (EB) against thermal overload. The device (1) has an actuating mechanism (B) which is brought into thermal contact with the component to be protected (EB) when in use, and which is capable of activating a switch (S) upon reaching a certain temperature T.sub.switch. The switch (S) can be used both as a disconnection switch and as a short-circuiting switch in relation to the component to be protected (EB), with the switch (S) furthermore having a selection mechanism (A) with which one can choose whether the switch (S) should be used as a disconnection switch or as a short-circuiting switch in relation to the component to be protected (EB).

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.