Abstract:
The present invention provides a multifunction resistor having an improved voltage variable material (“VVM”). More specifically, the present invention provides a polymer VVM that has been formulated with a high percentage loading of conductive and/or semiconductive particles. A known length of the relatively conductive VVM is placed between adjacent electrodes to produce a desired Ohmic normal state resistance. When an electrostatic discharge event occurs, the VVM of the multifunctional resistor becomes highly conductive and dissipates the ESD threat. One application for this “resistor” is the termination of a transmission line, which prevents unwanted reflections and distortion of high frequency signals.
Abstract:
A circuit protection device, including a conductor connected to first and second terminals and a spring exerting force on the conductor to move the conductor away from the first and/or second terminals when an over-voltage or over-temperature condition occurs within a charging circuit. One or more heat generating resistive elements melts material associated with one or more connection points of the conductor thereby releasing the conductor such that the spring moves the conductor to create an open circuit.
Abstract:
A fuse element includes a substrate disposed between first and second terminals. The substrate includes an electrically insulative material. A conductive film is disposed on a first surface of the substrate and in electrical contact with the first terminal and second terminals.
Abstract:
A high voltage fuse is disclosed. The high voltage fuse is compact and includes a molded plastic housing that holds connecting terminals, a fuse element, and optionally, a spring between one of the terminals and the fuse element or thin wire. When the fuse opens upon melting of the fuse element, the spring pulls apart ends of the wire and separates them as far as the spring and housing allow. The terminals may be mounted in separated parts of the housing, separated in some embodiments by the spring acting as an arc barrier. When the fuse element melts and the ends are pulled apart, the separation itself, or the arc barrier, prevents arcing between ends of the fuse element. In another embodiment, the housing itself furnishes a non-conducting plastic spring which urges the fuse link apart, the spring itself dividing the housing into two separate parts to prevent arcing.
Abstract:
An electrical circuit protection device has an overcurrent protection portion and an overvoltage protection portion. The overcurrent protection portion has a surface. The overvoltage protection portion is disposed on the surface and thermally coupled to the overcurrent protection portion. A number of terminations connect the overcurrent protection portion and the overvoltage protection portion to a printed circuit board or other electrical circuit.
Abstract:
An arrangement of voltage variable materials for the protection of electrical components from electrical overstress (EOS) transients. A device having a plurality of electrical leads, a ground plane and a layer of voltage variable material. The voltage variable material physically bonds the plurality of electrical leads to one another as well as provides an electrical connection between the plurality of electrical leads and the ground plane. A die having a circuit integrated therein is attached to the ground plane. Conductive members electrically connect the plurality of electrical leads to the integrated circuit. At normal operating voltages, the voltage variable material has a high resistance, thus channeling current from the electrical leads to the integrated circuit via the conductive members. In response to a high voltage EOS transient, the voltage variable material essentially instantaneously switches to a low resistance state, channeling the potentially harmful EOS transient to the ground plane and away from the integrated circuit.
Abstract:
The present invention provides an integrated overvoltage and overcurrent circuit protection device for use in telecommunication circuits. The integrated protected circuit device combines an overcurrent device and a fuse and an overvoltage protection device such as a thyristor to respectively protect against overcurrent conditions and transient overvoltages. Integration of the two devices in a common package ensures proper coordination and matching of the components, reduces the final product cost and reduces the physical space required on a telecommunications circuit for overvoltage and overcurrent circuit protection.
Abstract:
A fuse in one embodiment includes first and second leads. A fuse element provides electrical communication between the first and second leads. The fuse element includes a material with a melting point of less than 250.degree. C. and acts as both an overcurrent fuse and a thermal fuse by melting when subjected to a predetermined current or upon reaching a predetermined temperature. A body houses the fuse element and portions of the first and second leads.
Abstract:
In one aspect of the present invention, subminiature fuses are soldered to a PCB via clips attached to the fuse end caps. The clips are physically attached to the PCB pads, enabling the fuse to be replaced if needed and providing thermal decoupling between the fuse and the heating sinking solder/PCB pads. The fuse and clips can also be picked and placed in one operation. In another aspect, improved fuse clips are provided that include tabs that separate the housing portions of the clips from the heating sinking solder/PCB pads. Such improved clips further enhance thermal decoupling. In a further aspect, an improved fuse is provided, in which the thermal decoupling tabs just described are provided directly with the fuse. In yet a further aspect, a thermally insulative fuse body is provided to further decouple the fuse element from its surroundings.
Abstract:
A gas-filled surge arrester includes at least two electrodes, a gas filling and an activating compound applied to at least one of said electrodes. The activating compound can include: (i) nickel powder in an amount of about 10% to about 35% by weight; (ii) potassium or sodium silicate in an amount of about 20% to about 40% by weight; (iii) titanium powder in an amount of about 5% to about 25% by weight; (iv) calcium titanium oxide in an amount of about 5% to about 15% by weight; and (v) sodium bromide in an amount of about 10% to about 20% by weight. Ignition striping process and resulting stripes from ink-jetting of striping material are disclosed.