The present invention proposes a protection device which has a large rated voltage and a large rated current, which is capable of sufficiently suppressing arc generation during activation, and which is also capable of providing suitable protection against overcurrent due to short circuiting or the like of a main circuit. The protection device of the present invention includes (i) a protection element which includes a first thermal fuse and a resistor, and in which the resistor generates heat as a result of current passing through the resistor when there are abnormalities, and the first thermal fuse is activated due to this heat and interrupts the current, (ii) a PTC element and a second thermal fuse which are electrically connected in parallel to the first thermal fuse and which are electrically connected in series to each other, and (iii) a current fuse which is electrically connected in series to the first thermal fuse.

A switch module of built-in anti-surge disconnection structure mainly comprises an overcurrent protection switch and has anti-surge and disconnection structures ingeniously built inside a fire-proof and heat-resisting housing. The present invention comprises a switch area formed by a binary alloy conductive spring leaf and two connecting points, an anti-surge area formed by at least one bare metal oxide varistor placed in the housing and a plurality of conductive plates, and a disconnection area formed by a spring element, a band, and a thermo-sensitive piece. When the connecting points in the switch area are contacting with each otherturning on the switchand an overvoltage occurs, the temperature of the metal oxide varistor would suddenly rise up to a degree higher than a pre-determined number, melting the thermo-sensitive piece, loosening and displacing the band, thus ejecting the spring element and forcing the connecting points detaching from each other to turn off the switch, so as to ensure more of electricity safety.

A switch may comprise a metal plate. A eutectic alloy may be proximate to the metal plate. An insulating material may be proximate to the insulating material. The insulating material may include a recess in the insulating material adjacent the eutectic alloy. A lead may be fixed in place by the insulating material. A first end of the lead is exposed from the insulating material by the recess.

A thermally activated safety switch for safeguarding a consumer of a power supply network of a vehicle, having a switch housing in a temperature-independent switching unit, which subject to the temperature thereof establishes an electrically conductive connection between two external terminals fed out of the switch housing, wherein the external terminals are fed out at opposite housing sides of the switch housing. On the one hand, the external terminals are provided for an electrical and mechanical terminal connection to the cable connection ends of a consumer to be protected, and on the other hand to a cable portion leading to an on-board power supply electronics, and are configured accordingly.

A thermally activated safety switch for safeguarding a consumer of a power supply network of a vehicle, having a switch housing in a temperature-independent switching unit, which subject to the temperature thereof establishes an electrically conductive connection between two external terminals fed out of the switch housing, wherein the external terminals are fed out at opposite housing sides of the switch housing. On the one hand, the external terminals are provided for an electrical and mechanical terminal connection to the cable connection ends of a consumer to be protected, and on the other hand to a cable portion leading to an on-board power supply electronics, and are configured accordingly.

Provided is a protecting device with a built-in heat generator that can handle higher voltages and higher currents and blows the current path more safely and quickly without causing damage inside the device. The protecting device includes: a fuse element 2 and a blowing member 3, and the blowing member 3 includes an insulating substrate 4, a heat generator 5, an insulating layer 6 covering the heat generator 5, a heat-generator lead-out electrode 7 superimposed with the heat generator 5 via the insulating layer 6, and a heat-dissipating portion 8 formed on the front surface 4a side of the insulating substrate 4 at least in an area superimposed with the heat generator 5 and is electrically independent from the heat-generator lead-out electrode 7, a holding electrode 10 formed on the back surface 4b of the insulating substrate 4 and holds the melted conductor 2a of the fuse element 2, and a through-hole 11 connecting the heat-generator lead-out electrode 7 and the holding electrode 10, the fuse element 2 being connected to the holding electrode 10.

Provided is a protecting device with a built-in heat generator that can handle higher voltages and higher currents and blows the current path more safely and quickly without causing damage inside the device. The protecting device includes: a fuse element 2 and a blowing member 3, and the blowing member 3 includes an insulating substrate 4, a heat generator 5, an insulating layer 6 covering the heat generator 5, a heat-generator lead-out electrode 7 superimposed with the heat generator 5 via the insulating layer 6, and a heat-dissipating portion 8 formed on the front surface 4a side of the insulating substrate 4 at least in an area superimposed with the heat generator 5 and is electrically independent from the heat-generator lead-out electrode 7, a holding electrode 10 formed on the back surface 4b of the insulating substrate 4 and holds the melted conductor 2a of the fuse element 2, and a through-hole 11 connecting the heat-generator lead-out electrode 7 and the holding electrode 10, the fuse element 2 being connected to the holding electrode 10.

A protection device includes a meltable member, an electrode set, and a heating element. The meltable member has a core metal layer and a bottom metal layer disposed therebelow, and a melting point of the bottom metal layer is lower than that of the core metal layer. The electrode set has a first electrode, a second electrode, and an auxiliary electrode. The auxiliary electrode is located between the first electrode and the second electrode, and is disposed under the meltable member, thereby contacting the bottom metal layer. The meltable member has a hollow part penetrating the core metal layer, by which the bottom metal layer on the auxiliary electrode is exposed. The heating element is disposed under the auxiliary electrode, thereby heating up and blowing the meltable member in the event of over-voltage.

A protection device includes a meltable member, an electrode set, and a heating element. The meltable member has a core metal layer and a bottom metal layer disposed therebelow, and a melting point of the bottom metal layer is lower than that of the core metal layer. The electrode set has a first electrode, a second electrode, and an auxiliary electrode. The auxiliary electrode is located between the first electrode and the second electrode, and is disposed under the meltable member, thereby contacting the bottom metal layer. The meltable member has a hollow part penetrating the core metal layer, by which the bottom metal layer on the auxiliary electrode is exposed. The heating element is disposed under the auxiliary electrode, thereby heating up and blowing the meltable member in the event of over-voltage.

A temperature-dependent switch having a switch housing, a temperature-dependent switching mechanism and a heating resistor component. The switch housing comprises a lower part made of electrically conductive material and a lid part which comprises a first section made of electrically conductive material and a second section made of electrically insulating material. The temperature-dependent switching mechanism comprises a movable contact part that establishes a first electrical connection between the lower part and a stationary contact part below a response temperature and interrupts the first electrical connection upon exceeding the response temperature. The heating resistor component is arranged inside the switch housing between the lid part and the lower part. The heating resistor component is electrically connected in series with the lower part and the first section of the lid part and electrically in parallel with the first electrical connection. The heating resistor component is arranged at a distance from the stationary contact part.