A circuit protection device including a positive temperature coefficient (PTC) device and a backup fuse electrically connected in series with one another, the backup fuse comprising a quantity of solder disposed on a dielectric chip and having a melting temperature that is higher than a trip temperature of the PTC device, wherein the a surface of the dielectric chip exhibits a de-wetting characteristic relative to the solder such that, when the solder is melted, the solder draws away from the surface to create a galvanic opening in the backup fuse.

A circuit protection device including a positive temperature coefficient (PTC) device and a backup fuse electrically connected in series with one another, the backup fuse comprising a quantity of solder disposed on a dielectric chip and having a melting temperature that is higher than a trip temperature of the PTC device, wherein the a surface of the dielectric chip exhibits a de-wetting characteristic relative to the solder such that, when the solder is melted, the solder draws away from the surface to create a galvanic opening in the backup fuse.

A fuse suitable for arc quenching is disclosed. The fuse incorporates a high-resistive material or element placed in parallel relationship with the fusible element to mitigate, minimize and/or prevent arcing during an overcurrent condition. By incorporating a high-resistive material or element in parallel with a fusible element an alternate or second path for current flow during an overcurrent condition is provided. As such, during normal operating conditions, current travels through the fusible element. However, during an overcurrent condition, the resistance through the fusible element increases. Once the resistance through the fusible element is greater than the resistance through the high-resistive material or element, the current will bypass the fusible element and travel through the high-resistive material or element. In this manner, arcing through the fusible element during the overcurrent condition can be prevented or minimized.

A fuse suitable for arc quenching is disclosed. The fuse incorporates a high-resistive material or element placed in parallel relationship with the fusible element to mitigate, minimize and/or prevent arcing during an overcurrent condition. By incorporating a high-resistive material or element in parallel with a fusible element an alternate or second path for current flow during an overcurrent condition is provided. As such, during normal operating conditions, current travels through the fusible element. However, during an overcurrent condition, the resistance through the fusible element increases. Once the resistance through the fusible element is greater than the resistance through the high-resistive material or element, the current will bypass the fusible element and travel through the high-resistive material or element. In this manner, arcing through the fusible element during the overcurrent condition can be prevented or minimized.

A varistor component and a method for securing a varistor component are disclosed. In an embodiment, a varistor includes a first external contact, a second external contact, a varistor electrically connected to the first external contact, a path between the varistor and the second external contact and an active releasing device including a shutter and a heat sensitive element, wherein the heat sensitive element releases the shutter under abnormal operation conditions and the shutter closes the path between the varistor and the second external contact.

A varistor component and a method for securing a varistor component are disclosed. In an embodiment, a varistor includes a first external contact, a second external contact, a varistor electrically connected to the first external contact, a path between the varistor and the second external contact and an active releasing device including a shutter and a heat sensitive element, wherein the heat sensitive element releases the shutter under abnormal operation conditions and the shutter closes the path between the varistor and the second external contact.

Electrical current sensing and monitoring methods include connecting sensing a voltage across a conductor having a non-linear resistance such as a fuse element. The current flowing in the conductor is calculated based on at least a first detected state of the sensed voltage and a thermal equilibrium characterization of the conductor.

Electrical current sensing and monitoring methods include connecting sensing a voltage across a conductor having a non-linear resistance such as a fuse element. The current flowing in the conductor is calculated based on at least a first detected state of the sensed voltage and a thermal equilibrium characterization of the conductor.

The present invention relates to a wire-wound fuse resistor, which has: an insulating rod which has a first end and a second end; one metal wire having a wire head and a wire tail, being helically wound around the insulating rod from the first end to the second end, and being cut at a middle portion thereof to form a first winding wire and a second winding wire, which are separated from each other; a connection part disposed at the cut portion for electrical connection between the first winding wire and the second winding wire, in which the melting temperature of the connection part is lower than that of the one wound metal wire, wherein the connection part is cut off depending on a predetermined melting temperature or melting speed of the wire-wound fuse resistor.

The present invention relates to a wire-wound fuse resistor, which has: an insulating rod which has a first end and a second end; one metal wire having a wire head and a wire tail, being helically wound around the insulating rod from the first end to the second end, and being cut at a middle portion thereof to form a first winding wire and a second winding wire, which are separated from each other; a connection part disposed at the cut portion for electrical connection between the first winding wire and the second winding wire, in which the melting temperature of the connection part is lower than that of the one wound metal wire, wherein the connection part is cut off depending on a predetermined melting temperature or melting speed of the wire-wound fuse resistor.