An over-current protection device comprises first and second electrode layers and a PTC material layer laminated therebetween. The PTC material layer comprises a polymer matrix, a conductive ceramic filler, a carbon-containing conductive filler, and an inner filler. The polymer matrix comprises a fluoropolymer having a melting point higher than 150° C. The inner filler is selected from one of aluminum nitride, silicon carbide, zirconium oxide, boron nitride, graphene, aluminum oxide, or any mixtures thereof, and comprises 2-10% by volume of the PTC material layer. The over-current protection device is able to mitigate negative temperature coefficient (NTC) behavior after trip of device, and achieves high hold current and high endurable power.

A polymer positive temperature coefficient (PPTC) material may include a polymer matrix, the polymer matrix defining a PPTC body; and a graphene filler component, disposed in the polymer matrix, wherein the graphene filler component comprises a plurality of graphene particles aligned along a predetermined plane of the PPTC body.

The invention relates to a switch including a switch housing, a contact system and a base disposed in the switch housing, a resistive element for diagnosing a state of a switch, and at least two terminals leading from the base. The resistive element has a specific resistance value. The resistive element is a conductive material formed on the base, the terminals being electrically connected by the conductive material.

A surface-mountable over-current protection device comprises at least one PTC material layer, a first conductive layer, a second conductive layer, a first electrode, a second electrode, an insulating layer, and a cover layer. The PTC material layer comprises crystalline polymer and conductive fillers dispersed therein. The first conductive layer and the second conductive layer are disposed on a first surface and a second surface of the PTC material layer, respectively. The first electrode and the second electrode are electrically connected to the first conductive layer and the second conductive layer, respectively. The insulating layer is disposed between the first electrode and the second electrode for insulation. The cover layer includes a fluorine-containing polymer, and wraps around an entire outer surface of the surface-mountable over-current protection device.

A novel heater is disclosed for a temperature sensitive actuator. The heater is a polymeric positive temperature coefficient (PPTC) device consisting of conductive filler and semi-crystalline polymer. The PPTC heater is strategically designed to have a predetermined self-regulation temperature suited to whatever application utilizes the heater. Physical characteristics of the PPTC heater, such as gap width and thickness, enable the current flow through the heater to be strategically controlled.

An over-current protection device includes first and second electrodes and a positive temperature coefficient (PTC) multilayered structure disposed between the first and second electrodes. The PTC multilayered structure includes a first polymer layer that is bonded to the first electrode, an intermediate layered unit that is bonded to said first polymer layer and that includes a second polymer layer, a third polymer layer that is bonded to and disposed between the intermediate layered unit and the second electrode. The first, second and third polymer layers respectively have first, second and third volume resistances, the second volume resistance being higher than the first and third volume resistances.

A novel heater is disclosed for a temperature sensitive actuator. The heater is a polymeric positive temperature coefficient (PPTC) device consisting of conductive filler and semi-crystalline polymer. The PPTC heater is strategically designed to have a predetermined self-regulation temperature suited to whatever application utilizes the heater. Physical characteristics of the PPTC heater, such as gap width and thickness, enable the current flow through the heater to be strategically controlled.

Disclosed herein is a method of manufacturing a secondary battery electrode containing a positive temperature coefficient (PTC) material, the method including (a) applying first slurry including a first mixture and a solvent mixed with each other to one surface of a planar current collector to generate a PTC material after drying, (b) applying second slurry including a second mixture, including an electrode active material, and a solvent mixed with each other to the first slurry applied to the current collector, which is in a non-dried state, and (c) drying the first slurry and the second slurry applied to the current collector.

A method for manufacturing a sheet of positive temperature coefficient (PTC) material includes providing a PTC material, grinding the PTC material into a powder, and inserting the ground PTC material into a press. The ground PTC material is compressed within the press until the PTC material defines a planar shape. The PTC material is then removed from the press to thereby provide a PTC sheet.

In one embodiment a varistor may include a ceramic body. The varistor may further comprise a multilayer coating disposed around the ceramic body. The multilayer coating may include a first layer comprising a phenolic material or a silicone material; and a second layer adjacent the first layer, the second layer comprising a high dielectric strength coating.