Patents Assigned to Littelfuse, Inc.
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Patent number: 7233474Abstract: An electrical protection device is provided. The device can be removably attached to or mounted inside of a power source, such as a vehicle, e.g., automobile, battery and can employ a replaceable fuse element. The device includes an overcurrent protection element, such as a fuse element, and provides any one or more of the following types of electrical protection: (i) overcurrent protection; (ii) accident or catastrophic event power cutout protection; and (iii) load dump protection. The system is configurable to protect certain vehicle electrical components from an overcurrent and allow others to operate independent of the overcurrent protection. Systems and methods employing the protection device are also illustrated and discussed.Type: GrantFiled: November 24, 2004Date of Patent: June 19, 2007Assignee: Littelfuse, Inc.Inventors: William P. Brown, Edwin James Harris, Jeffrey John Ribordy
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Patent number: 7202770Abstract: The present invention provides overvoltage circuit protection. Specifically, the present invention provides a voltage variable material (“VVM”) that includes an insulative binder that is formulated to intrinsically adhere to conductive and nonconductive surfaces. The binder and thus the VVM is self-curable and may be applied to an application in the form of an ink, which dries in a final form for use. The binder eliminates the need to place the VVM in a separate device or for separate printed circuit board pads on which to electrically connect the VVM. The binder and thus the VVM can be directly applied to many different types of substrates, such as a rigid (FR-4) laminate, a polyimide or a polymer. The VVM can also be directly applied to different types of substrates that are placed inside a device.Type: GrantFiled: April 8, 2003Date of Patent: April 10, 2007Assignee: Littelfuse, Inc.Inventors: Edwin James Harris, Scott Davidson, David Perry, Steven J. Whitney
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Patent number: 7183891Abstract: A voltage variable material (“VVM”) including an insulative binder that is formulated to intrinsically adhere to conductive and non-conductive surfaces is provided. The binder and thus the VVM is self-curable and applicable in a spreadable form that dries before use. The binder eliminates the need to place the VVM in a separate device or to provide separate printed circuit board pads on which to electrically connect the VVM. The binder and thus the VVM can be directly applied to many different types of substrates, such as a rigid FR-4 laminate, a polyimide, a polymer or a multilayer PCB via a process such as screen or stencil printing. In one embodiment, the VVM includes two types of conductive particles, one with a core and one without a core. The VVM can also have core-shell type semiconductive particles.Type: GrantFiled: October 5, 2004Date of Patent: February 27, 2007Assignee: Littelfuse, Inc.Inventors: Edwin James Harris, Tushar Vyas, Timothy Pachla, James A. Colby
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Patent number: 7180719Abstract: 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.Type: GrantFiled: September 26, 2003Date of Patent: February 20, 2007Assignee: Littelfuse, Inc.Inventor: Stephen J. Whitney
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Patent number: 7132922Abstract: A voltage variable material (“VVM”) including an insulative binder that is formulated to intrinsically adhere to conductive and non-conductive surfaces is provided. The binder and thus the VVM is self-curable and applicable in a spreadable form that dries before use. The binder eliminates the need to place the VVM in a separate device or to provide separate printed circuit board pads on which to electrically connect the VVM. The binder and thus the VVM can be directly applied to many different types of substrates, such as a rigid (FR-4) laminate, a polyimide or a polymer. The VVM can also be directly applied to different types of substrates that are placed inside a device. In one embodiment, the VVM includes doped semiconductive particles having a core, such which can be silicon, and an inert coating, which can be an oxide. The particles are mixed in the binder with conductive particles.Type: GrantFiled: December 23, 2003Date of Patent: November 7, 2006Assignee: Littelfuse, Inc.Inventors: Edwin James Harris, Tushar Vyas, Stephen J. Whitney
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Patent number: 6982859Abstract: An integrated overvoltage and overcurrent circuit protection device for use in telecommunication circuits. The integrated circuit protection device combines a overcurrent device such as a fuse and a 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.Type: GrantFiled: August 28, 2000Date of Patent: January 3, 2006Assignee: Littelfuse, Inc.Inventor: Stephen J. Whitney
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Patent number: 6935879Abstract: The present invention provides connectors having circuit protection. Specifically, the present invention provides a device that operates with existing or new connectors to provide overvoltage protection to same. The device includes a strip of conductive material along which voltage variable material (“VVM”) is applied. The strip also includes an exposed portion not having the VVM deposition. The VVM contacts a plurality of signal conductors of the connector. The exposed portion contacts at least one ground conductor of the connector. When an overvoltage condition occurs along one of the signal conductors, the VVM switches from a high impedance to a low impedance state, allowing the transient threat to dissipate, at least in part, to one or more ground conductor.Type: GrantFiled: July 10, 2002Date of Patent: August 30, 2005Assignee: Littelfuse, Inc.Inventors: Stephen J. Whitney, David Perry
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Patent number: 6878004Abstract: The present invention provides a fuse block having a plurality of fuse connections. The fuse connections include an array of embedded terminals that contact the initially provided fuse elements. When one of the fuse elements opens, an operator remakes the open connection by inserting an external replacement fuse. The fuse connections therefore eliminate the need to initially provide separate external fuses. In an embodiment, the terminals include fork shaped projections that receive one of the terminals of the replacement fuse, which also eliminates the need for additional female inserts commonly found in automobile fuse blocks. The fuse block is simple, wherein a plurality of same may be provided in an automobile to cut down on long lengths of wire running from load devices to a traditional, single centrally located fuse block.Type: GrantFiled: March 4, 2002Date of Patent: April 12, 2005Assignee: Littelfuse, Inc.Inventor: Seibang Oh
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Patent number: 6838972Abstract: An electrical circuit protection device with three supporting substrates, two PTC elements, and first and second end terminations. The first and third substrates have an electrode formed on a first surface thereof. The second substrate has electrodes formed on both surfaces thereof. The first PTC element is laminated between the first and second substrates, electrically connecting the first electrodes formed on the first and second substrates. The second PTC element is laminated between the second and third substrates, electrically connecting the second electrode formed on the second substrate and the first electrode formed on the third substrate. The end terminations wraps around opposite ends of the device. The first end termination is in electrical contact with the first electrodes formed on the second and third substrates and the second end termination is in electrical contact with the first electrode formed on the first substrate and the second electrode formed on the second substrate.Type: GrantFiled: February 22, 2000Date of Patent: January 4, 2005Assignee: Littelfuse, Inc.Inventors: Anthony D. Minervini, Honorio S. Luciano
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Patent number: 6815841Abstract: A fuse arrangement for use in a vehicle is provided having a configuration wherein a common bus terminal connected to a voltage supply is connected to terminals of one or more axial fuses. The other fuse terminals are, in turn, connected to a wiring harness that is located on an opposite side of the fuse box from the common bus terminal in a base of a fuse box. Additionally, the present invention includes a fuse array including a planar substrate with fuses constructed on the substrate by film metallization. Furthermore, the invention includes a carrier strip used for packaging automotive fuses that is made of a flexible material capable of being rolled into a package for shipping to an end user. The invention also includes a mini fuse having reduced terminal spacing for use in vehicles with mixed voltage systems wherein the reduced terminal spacing fuse is used for a particular voltage.Type: GrantFiled: November 3, 1999Date of Patent: November 9, 2004Assignee: Littelfuse, Inc.Inventors: William P. Brown, James Chen, Carl S. Reid, Demetrios Thanopoulos, Stephen J. Whitney
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Patent number: 6693508Abstract: 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.Type: GrantFiled: February 9, 2000Date of Patent: February 17, 2004Assignee: Littelfuse, Inc.Inventors: Stephen J. Whitney, Louis Rector, Hugh M. Hyatt, Anthony D. Minervini, Honorio S. Luciano
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Patent number: 6642297Abstract: A composition for providing protection against electrical overstress (EOS) comprising an insulating binder, doped semiconductive particles, and semiconductive particles. The composite materials exhibit a high electrical resistance to normal operating voltage values, but in response to an EOS transient switch to a low electrical resistance and clamp the EOS transient voltage to a low level for the duration of the EOS transient.Type: GrantFiled: January 15, 1999Date of Patent: November 4, 2003Assignee: Littelfuse, Inc.Inventors: Hugh M. Hyatt, Louis P. Rector
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Patent number: 6642834Abstract: The invention is a blade fuse having a housing section and a fusible element. The housing includes an insulating portion or tab extending from the housing section, and disposed between opposite ends of the fusible element. One aspect of the invention is a blade fuse where the insulating tab is integral with the housing. The insulating tab may be integral with the head portion of the housing, and the insulating tab may extend downwardly from the head portion. In yet another embodiment, the invention is directed to a one-piece, metallic element for a blade fuse. The blade fuse element has a fusible link and a pair of terminals. The fusible element extends above, rather than between, the terminals.Type: GrantFiled: March 1, 2000Date of Patent: November 4, 2003Assignee: Littelfuse, Inc.Inventors: Seibang Oh, James Jie Chen
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Patent number: 6636404Abstract: An integrated overvoltage and overcurrent circuit protection device for use in telecommunication circuits. The integrated circuit protection device combines a overcurrent device such as a fuse and a overvoltage protection device such as a thyristor to respectively protect against overcurrent conditions and transient overvoltages. Integration of multiple 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.Type: GrantFiled: August 28, 2000Date of Patent: October 21, 2003Assignee: Littelfuse, Inc.Inventors: Stephen J. Whitney, David Zhang, Scott Davidson
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Patent number: 6582647Abstract: The present invention provides a method for heat treating a polymer PTC composition to increase the peak resistivity of the composition making it especially well suited for high voltage applications. A polymer PTC composition having a melting point temperature Tmp is provided. The temperature of the polymer PTC composition is increased at a rate, r1, to a temperature greater than Tmp. The temperature of polymer PTC composition is held at the temperature greater than Tmp for a predetermined period of time. Then the temperature of the polymer PTC composition is decreased to a temperature less than Tmp at a rate, r2, wherein r2 is greater than r1.Type: GrantFiled: September 30, 1999Date of Patent: June 24, 2003Assignee: Littelfuse, Inc.Inventors: Tom J. Hall, Michael J. Weber
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Patent number: 6579931Abstract: Positive temperature coefficient (“PTC”) materials for use in electronic components for the protection of electrical circuits. Through the use of an organo-metallic coupling agent, the room temperature resistivity of polymeric PTC materials may be reduced. The PTC materials of the present invention include a polyolefin, a conductive filler and an organo-metallic coupling agent, and have an electrical resistivity at 25° C. of less than 1 ohm cm.Type: GrantFiled: February 25, 2000Date of Patent: June 17, 2003Assignee: Littelfuse, Inc.Inventor: Tom J. Hall
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Patent number: 6577222Abstract: A fuse is disclosed having terminal leads electrically connected by a fusible link, and insulated within a housing. The housing is preferably made from a material which burns cleanly and has improved ablative qualities to prevent accelerated arcing within the plasma generated by the housing during high energy periods. The desired material should have an arc resistance of about 60 to about 120 seconds, a CTI of about 250 to about 400 volts, an arc ignition resistance of greater than 120 arcs, an arc tracking rate of about 25 to about 80 millimeters per minute, and a hot wire ignition value of greater than 120 seconds. Such material being capable of increasing the voltage rating of a standard 32 volt fuse almost ten-fold to about 300 volts.Type: GrantFiled: March 30, 2000Date of Patent: June 10, 2003Assignee: Littelfuse, Inc.Inventors: David J. Krueger, Seibang Oh
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Patent number: 6549114Abstract: 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.Type: GrantFiled: August 19, 1999Date of Patent: April 15, 2003Assignee: Littelfuse, Inc.Inventors: Stephen J. Whitney, Louis Rector, Hugh M. Hyatt, Anthony D. Minervini, Honorio S. Luciano
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Patent number: 6547597Abstract: An apparatus and method for incorporating surface mount components into connectors. In an embodiment, an apparatus that houses a printed circuit board having a surface mount component is provided. The apparatus includes a body. A plurality of leads are fixed to the body so that an external electrical device is enabled to electrically communicate with the leads. A clip extends from each lead and receives an end of a printed circuit board.Type: GrantFiled: July 10, 2001Date of Patent: April 15, 2003Assignee: Littelfuse, Inc.Inventor: Edwin James Harris, IV
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Patent number: 6522515Abstract: A connector port for providing power to a serial device and termination of differential signals received therefrom is provided. The port includes circuitry providing a data interface and a power interface. The data interface is operably connected between an input differential wire pair and an output differential wire pair for providing termination of the input wire pair and transmission of signal onto the output wire pair. Further, the power interface includes a fuse link operably connected between a voltage input and a voltage output for providing overcurrent protection.Type: GrantFiled: January 6, 2000Date of Patent: February 18, 2003Assignee: Littelfuse, Inc.Inventor: Stephen J. Whitney