Disclosed is an SMD micro mixed fuse with a thermal fuse function that stably operates at high voltage surges and can interrupt electrical current at a predetermined temperature. The SMD micro mixed fuse includes: a fuse substrate provided with a first electrode and a second electrode; a variator layer formed on a front surface of the fuse substrate; a first contact terminal and a second contact terminal respectively arranged at a first side and a second side of a front surface of the varistor layer and respectively connected to the first electrode and the second electrode; at least one thermal fuse that is arranged on the front surface of the variator layer, is not connected to the first and second contact terminals, but is connected to the fuse substrate; and a fusible element that is wire-bonded to the first and second contact terminals and is not connected to the thermal fuse.

A temperature-dependent switch has a temperature-dependent switching mechanism, a housing accommodating the switching mechanism, two first connections between which first connections the switching mechanism makes or interrupts an electrically conductive connection depending on the temperature of said switching mechanism, and a heating resistor that is arranged on an outside of the housing and is connected electrically in series with the two connections. The heating resistor is a sheet-like metal part that is welded to the housing and carries a further connection.

A temperature-dependent switch has a temperature-dependent switching mechanism, a housing accommodating the switching mechanism, two first connections between which first connections the switching mechanism makes or interrupts an electrically conductive connection depending on the temperature of said switching mechanism, and a heating resistor that is arranged on an outside of the housing and is connected electrically in series with the two connections. The heating resistor is a sheet-like metal part that is welded to the housing and carries a further connection.

A thermal sensor with a simple structure can secure the deformability of a bimetal, and accurately control the position of the bimetal, to increase the response speed (heat response) of the bimetal. The thermal sensor includes a bimetal, a case, and a cover member. A pressing portion is provided between the cover member and the bimetal to press the bimetal to a bottom portion of the case. The pressing portion is deformable in accordance with the deformation of the bimetal.

A thermal sensor with a simple structure can secure the deformability of a bimetal, and accurately control the position of the bimetal, to increase the response speed (heat response) of the bimetal. The thermal sensor includes a bimetal, a case, and a cover member. A pressing portion is provided between the cover member and the bimetal to press the bimetal to a bottom portion of the case. The pressing portion is deformable in accordance with the deformation of the bimetal.

A disconnection device for electrically disconnecting an electrical appliance from an electrode pair having an electrically isolating holder between the electrode pair. The holder has an electrically conductive substance disconnectable from the electrode pair under gravity forces.

A disconnection device for electrically disconnecting an electrical appliance from an electrode pair having an electrically isolating holder between the electrode pair. The holder has an electrically conductive substance disconnectable from the electrode pair under gravity forces.

A heat-reactive switch includes an airtight container with a housing and a lid plate, two conductive terminal pins fixed in through-holes in the lid plate, a fixed contact point fixed on one of the conductive terminal pins, a heater connected to the other conductive terminal pin and to the lid plate, a heat-reactive plate connected to the housing internal surface, the bending direction becoming inverted at a predetermined temperature, and a mobile contact point provided at the end of the heat-reactive plate. A heating element has a plurality of serpentine portions made from a metal plate in ribbon form, disposed between the lid plate and the heat-reactive plate so as to be parallel thereto. At least two of the serpentine portions are disposed to face each other while sandwiching the conductive terminal pin. Each portion follows the inner peripheral surface of the housing and have planar portions facing each other.

A heat-reactive switch includes an airtight container with a housing and a lid plate, two conductive terminal pins fixed in through-holes in the lid plate, a fixed contact point fixed on one of the conductive terminal pins, a heater connected to the other conductive terminal pin and to the lid plate, a heat-reactive plate connected to the housing internal surface, the bending direction becoming inverted at a predetermined temperature, and a mobile contact point provided at the end of the heat-reactive plate. A heating element has a plurality of serpentine portions made from a metal plate in ribbon form, disposed between the lid plate and the heat-reactive plate so as to be parallel thereto. At least two of the serpentine portions are disposed to face each other while sandwiching the conductive terminal pin. Each portion follows the inner peripheral surface of the housing and have planar portions facing each other.

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.