Abstract: A circuit protection device includes a substrate with first and second electrodes connected to the circuit to be protected. The circuit protection device also includes a heater element. A sensing element facilitates an electrical connection between the first and second electrodes. A flux material is provided around the sensing element. In a preferred embodiment, the flux contains a first component that is a polar material and a second component that is a non-polar material. A spring element exerts a force on the sensing element. The sensing element resists the force applied by the spring element. Upon detection of an activation, or fault, condition, the sensing element loses resilience and no longer resists the force exerted by the spring element, resulting in the spring element severing the electrical connection between the first and second electrodes. The flux allows the spring element to sever the electrical connection without dragging the sensing element.

Abstract: A circuit protection device is configured to protect circuit elements under any one of the following three activation conditions: an over current condition, an over temperature condition, and an activation control current received by a heater element. The circuit element includes first and second electrodes, and the heater element. A sliding contact is connected by a sensing element to the first electrode, second electrode, and heater element, thereby bridging and providing a conductive path between each. A spring element is held in tension by, and exerts a force against, the sliding contact. Upon detection of any one of three activation conditions, the sensing element releases the sliding contact and the force exerted by the spring element moves the sliding contact to another location on the substrate at which the sliding contact no longer provides a conductive path between the first electrode, second electrode, and heater element.

Abstract: A surface-mountable electrical circuit protection device includes layers defining a first PPTC resistive element, a second PPTC resistive element, and at least one heat-generating electrical component such as a planar zener diode chip positioned between, and in thermal contact with, the first and second PPTC elements, such that an electrical current above a threshold level passing through the component causes the component to heat, the heat being transferred to the PPTC resistive elements and tripping at least one, and preferably both of the first or second PPTC elements to a high resistance state. A series of edge-formed terminal electrodes enable surface-mount connection of the first and second PPTC elements and the electrical component to an electrical circuit substrate, such as a printed circuit board. A method for making the device is also disclosed.

Abstract: A circuit protection device includes a substrate with first and second electrodes connected to the circuit to be protected. The circuit protection device also includes a heater element between the first and second electrodes. A sliding contact is connected by a sensing element to the first electrode, second electrode, and heater element, thereby bridging and providing a conductive path between each. A spring element is held in tension by, and exerts a force parallel to a length of the substrate against, the sliding contact. Upon detection of an activation condition, the sensing element releases the sliding contact and the force exerted by the spring element moves the sliding contact to another location on the substrate at which the sliding contact no longer provides a conductive path between the first electrode, second electrode, and heater element.

Abstract: A circuit protection device includes a substrate with first and second electrodes connected to the circuit to be protected. The circuit protection device also includes a heater element. A sensing element facilitates an electrical connection between the first and second electrodes. A flux material is provided around the sensing element. In a preferred embodiment, the flux contains a first component that is a polar material and a second component that is a non-polar material. A spring element exerts a force on the sensing element. The sensing element resists the force applied by the spring element. Upon detection of an activation, or fault, condition, the sensing element loses resilience and no longer resists the force exerted by the spring element, resulting in the spring element severing the electrical connection between the first and second electrodes. The flux allows the spring element to sever with electrical connection without dragging the sensing element.

Abstract: A surface-mountable electrical circuit protection device includes layers defining a first PPTC resistive element, a second PPTC resistive element, and at least one heat-generating electrical component such as a planar zener diode chip positioned between, and in thermal contact with, the first and second PPTC elements, such that an electrical current above a threshold level passing through the component causes the component to heat, the heat being transferred to the PPTC resistive elements and tripping at least one, and preferably both of the first or second PPTC elements to a high resistance state. A series of edge-formed terminal electrodes enable surface-mount connection of the first and second PPTC elements and the electrical component to an electrical circuit substrate, such as a printed circuit board. A method for making the device is also disclosed.

Abstract: A circuit protection device includes a substrate with first and second electrodes connected to the circuit to be protected. The circuit protection device also includes a heater element between the first and second electrodes. A sliding contact is connected by a sensing element to the first electrode, second electrode, and heater element, thereby bridging and providing a conductive path between each. A spring element is held in tension by, and exerts a force parallel to a length of the substrate against, the sliding contact. Upon detection of an activation condition, the sensing element releases the sliding contact and the force exerted by the spring element moves the sliding contact to another location on the substrate at which the sliding contact no longer provides a conductive path between the first electrode, second electrode, and heater element.

Abstract: A circuit protection device includes a substrate with first and second electrodes connected to the circuit to be protected. The circuit protection device also includes a heater element between the first and second electrodes. A sliding contact is connected by a sensing element to the first electrode, second electrode, and heater element, thereby bridging and providing a conductive path between each. A spring element is held in tension by, and exerts a force parallel to a length of the substrate against, the sliding contact. A flux material is provided around the sensing element. Upon detection of an activation condition, the sensing element releases the sliding contact and the force exerted by the spring element moves the sliding contact to another location on the substrate at which the sliding contact no longer provides a conductive path between the first electrode, second electrode, and heater element. The flux allows the sliding contact to move without dragging the sensing material.

Abstract: A circuit protection device is configured to protect circuit elements under any one of the following three activation conditions: an over current condition, an over temperature condition, and an activation control current received by a heater element. The circuit element includes first and second electrodes, and the heater element. A sliding contact is connected by a sensing element to the first electrode, second electrode, and heater element, thereby bridging and providing a conductive path between each. A spring element is held in tension by, and exerts a force against, the sliding contact. Upon detection of any one of three activation conditions, the sensing element releases the sliding contact and the force exerted by the spring element moves the sliding contact to another location on the substrate at which the sliding contact no longer provides a conductive path between the first electrode, second electrode, and heater element.

Abstract: A surface-mountable electrical circuit protection device includes layers defining a first PPTC resistive element, a second PPTC resistive element, and at least one heat-generating electrical component such as a planar zener diode chip positioned between, and in thermal contact with, the first and second PPTC elements, such that an electrical current above a threshold level passing through the component causes the component to heat, the heat being transferred to the PPTC resistive elements and tripping at least one, and preferably both of the first or second PPTC elements to a high resistance state. A series of edge-formed terminal electrodes enable surface-mount connection of the first and second PPTC elements and the electrical component to an electrical circuit substrate, such as a printed circuit board. A method for making the device is also disclosed.

Abstract: A process for manufacturing a composite polymeric circuit protection device in which a polymeric assembly is provided and is then subdivided into individual devices. The assembly is made by providing first and second laminates, each of which includes a laminar polymer element having at least one conductive surface, providing a pattern on at least one of the conductive surfaces on one laminate, securing the laminates in a stack in a desired configuration, at least one conductive surface of at least one of the laminates forming an external conductive surface of the stack, and making a plurality of electrical connections between a conductive surface of the first laminate and a conductive surface of the second laminate. The laminar polymer elements may be PTC conductive polymer compositions, so that the individual devices made by the process exhibit PTC behavior.

Abstract: A surface-mountable electrical circuit protection device includes layers defining a first PPTC resistive element, a second PPTC resistive element, and at least one heat-generating electrical component such as a planar zener diode chip positioned between, and in thermal contact with, the first and second PPTC elements, such that an electrical current above a threshold level passing through the component causes the component to heat, the heat being transferred to the PPTC resistive elements and tripping at least one, and preferably both of the first or second PPTC elements to a high resistance state. A series of edge-formed terminal electrodes enable surface-mount connection of the first and second PPTC elements and the electrical component to an electrical circuit substrate, such as a printed circuit board. A method for making the device is also disclosed.

Abstract: A process for manufacturing a composite polymeric circuit protection device in which a polymeric assembly is provided and is then subdivided into individual devices (2). The assembly is made by providing first and second laminates (7,8), each of which includes a laminar polymer element having at least one conductive surface, providing a pattern on at least one of the conductive surfaces on one laminate, securing the laminates in a stack (1) in a desired configuration, at least one conductive surface of at least one of the laminates forming an external conductive surface (3) of the stack, and making a plurality of electrical connections (31,51) between a conductive surface of the first laminate and a conductive surface of the second laminate. The laminar polymer elements may be PTC conductive polymer compositions, so that the individual devices made by the process exhibit PTC behavior.

Abstract: A process for manufacturing a composite polymeric circuit protection device in which a polymeric assembly is provided and is then subdivided into individual devices (2). The assembly is made by providing first and second laminates (7,8), each of which includes a laminar polymer element having at least one conductive surface, providing a pattern on at least one of the conductive surfaces on one laminate, securing the laminates in a stack (1) in a desired configuration, at least one conductive surface of at least one of the laminates forming an external conductive surface (3) of the stack, and making a plurality of electrical connections (31,51) between a conductive surface of the first laminate and a conductive surface of the second laminate. The laminar polymer elements may be PTC conductive polymer compositions, so that the individual devices made by the process exhibit PTC behavior. Additional electrical components may be attached directly to the surface of the device or assembly.

Abstract: A process for manufacturing a composite polymeric circuit protection device in which a polymeric assembly is provided and is then subdivided into individual devices. The assembly is made by providing first and second laminates, each of which includes a laminar polymer element having at least one conductive surface, providing a pattern on at least one of the conductive surfaces on one laminate, securing the laminates in a stack in a desired configuration, at least one conductive surface of at least one of the laminates forming an external conductive surface of the stack, and making a plurality of electrical connections between a conductive surface of the first laminate and a conductive surface of the second laminate. The laminar polymer elements may be PTC conductive polymer compositions, so that the individual devices made by the process exhibit PTC behavior.

Abstract: A process for manufacturing a composite polymeric circuit protection device in which a polymeric assembly is provided and is then subdivided into individual devices. The assembly is made by providing first and second laminates, each of which includes a laminar polymer element having at least one conductive surface, providing a pattern on at least one of the conductive surfaces on one laminate, securing the laminates in a stack in a desired configuration, at least one conductive surface of at least one of the laminates forming an external conductive surface of the stack, and making a plurality of electrical connections between a conductive surface of the first laminate and a conductive surface of the second laminate. The laminar polymer elements may be PTC conductive polymer compositions, so that the individual devices made by the process exhibit PTC behavior.

Abstract: A process for manufacturing a composite polymeric circuit protection device in which a polymeric assembly is provided and is then subdivided into individual devices (2). The assembly is made by providing first and second laminates (7,8), each of which includes a laminar polymer element having at least one conductive surface, providing a pattern on at least one of the conductive surfaces on one laminate, securing the laminates in a stack (1) in a desired configuration, at least one conductive surface of at least one of the laminates forming an external conductive surface (3) of the stack, and making a plurality of electrical connections (31,51) between a conductive surface of the first laminate and a conductive surface of the second laminate. The laminar polymer elements may be PTC conductive polymer compositions, so that the individual devices made by the process exhibit PTC behavior. Additional electrical components may be attached directly to the surface of the device or assembly.

Abstract: A generally rectangular, planar electrical overcurrent sensing device having a top major surface and a bottom major surface includes a patterned metal foil conductor defined along the top major surface. The metal foil conductor has a first electrode region at one end region, a second electrode region at an opposite end region, and a current-concentrating region extending between the first electrode portion and the second electrode portion. The device further includes a planar sheet of a composition which exhibits PTC behavior and which comprises an organic polymer having a particulate conductive filler dispersed therewithin. The planar sheet has a first major surface in thermal contact with the bridging portion and has an opposite second major surface.

Abstract: A method is disclosed for making a liquid crystal composite including a dye. The method comprises forming volumes in which a liquid crystal material is surrounded by a containment medium, forming a dye dispersion, combining the dye dispersion and the volumes of liquid material, and treating that combination to facilitate the transfer of the dye into the volumes of liquid crystal material.

Abstract: A liquid crystal display is made from an encapsulated liquid crystal structure comprising a liquid crystal composition dispersed in a containment medium. Selected additives may be added to the encapsulated liquid crystal structure to improve performance characteristics such as the operating field, the hysteresis, and the voltage holding ratio.