Patents Assigned to Littelfuse, Inc.
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Publication number: 20150228429Abstract: A circuit protection device including a housing (15) defining a chamber (19) and a metal oxide varistor (MOV) stack (310) disposed within the chamber (19). A first spring (330a) is electrically attached at a first end to a first input terminal (311a) of the MOV stack (310) by a solder connection (30) and at a second end to a first input line (20a). The first spring (330a) is biased away from the first input terminal (311a). A second spring (330b) is electrically attached to a second input terminal (311b) of the MOV stack (310) by a solder connection (40) and at a second end to a second input line (20b). The second conductive spring (330b) is biased away from the second input terminal (311b). When an overvoltage condition occurs, heat generated by the MOV stack (310) melts at least one of the first or second solder connections (30, 40) to allow the corresponding springs to be displaced away from the respective MOV stack (310) input terminals (311 a, 311 b), thereby creating an opening circuit.Type: ApplicationFiled: October 26, 2012Publication date: August 13, 2015Applicant: LITTELFUSE, INC.Inventors: Wen Yang, Hailang Tang, Huawei Yin, Stephen J. Whitney, G. Todd Dietsch
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Publication number: 20150200067Abstract: An improved ceramic chip fuse with offset fuse element comprising a plurality of non-conductive layers; a fuse element disposed between ones of the plurality of non-conductive layers such that more non-conductive layers are above the fuse element than below the fuse element relative to a vertical axis of the fuse; first and second conductive terminals electrically connected to the fuse element to connect the fuse to a circuit to be protected and a source of power.Type: ApplicationFiled: January 9, 2015Publication date: July 16, 2015Applicant: LITTELFUSE, INC.Inventor: Olga Spaldon-Stewart
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Publication number: 20150200537Abstract: Secondary battery protection circuits for protecting a battery from charging and/or discharging faults are provided. A secondary battery protection circuit may include a first terminal and a second terminal, a transistor electrically connected between the first terminal and the second terminal, a fuse electrically coupled to the gate of the transistor, and a fuse control circuit configured to cause current sufficient to open the fuse to pass through the fuse in the event of a fault condition.Type: ApplicationFiled: January 9, 2015Publication date: July 16, 2015Applicant: LITTELFUSE, INC.Inventors: Sam S. Kang, John M. Jorgensen, Bharat Shenoy, Kunghao Yu
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Patent number: 9082622Abstract: Ferroic circuit elements that include a set of conductive structures that are at least partially embedded within a ferroic medium are disclosed. The ferroic medium may be a voltage switched dielectric material that includes ferroic particles in accordance with various embodiments. A ferroic circuit element may be at least partially embedded within a substrate in accordance with embodiments of the current invention as an embedded ferroic circuit element. An embedded ferroic circuit element that is an inductor in accordance with embodiments of the current invention may be denoted as an embedded ferroic inductor. An embedded ferroic circuit element that is a capacitor in accordance with embodiments of the current invention may be denoted as an embedded ferroic capacitor.Type: GrantFiled: May 24, 2011Date of Patent: July 14, 2015Assignee: LITTELFUSE, INC.Inventors: Robert Fleming, Bhret Graydon, Daniel Vasquez, Junjun Wu, Farhad Razavi
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Patent number: 9084354Abstract: A method for designing a printed circuit board to meet a specification is described. A first voltage switchable dielectric material is placed in apposition with a first copper foil. A second voltage switchable dielectric material is placed in apposition with a second copper foil. An arcuate portion of the first copper foil is placed in apposition with a first side of an aluminum member, an adhesive substance being situated between the first copper foil and the first side of the aluminum member. An arcuate portion of the second copper foil in is placed apposition with a second side of the aluminum member, an adhesive substance being situated between the second copper foil and the second side of the aluminum member.Type: GrantFiled: August 28, 2012Date of Patent: July 14, 2015Assignee: LITTELFUSE, INC.Inventors: Robert Fleming, Lex Kosowsky, Shurui Shang, Bhret Graydon, Xiaofeng Chen, Glen Irvin
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Publication number: 20150165992Abstract: A power distribution module for a vehicle includes an insulating housing including a component grid, the component grid defining a plurality of circuit protection footprints, the housing further including at least one connector mount or terminal mating location; a printed circuit board (“PCB”) located within the housing and beneath the component grid, the PCB holding a plurality of fuse mounting terminals and at least one connector mounting terminal, the PCB including a plurality of conducting traces connecting the fuse mounting terminals to the at least one connector mounting terminal; and a cover that threadingly engages the housing, the threading engagement leading to a locking of the cover to the housing that tends to prevent the cover from loosening from the housing when the vehicle is being driven, the locking of the cover able to be overcome by a person so that the cover can be unthreaded readily from the housing.Type: ApplicationFiled: February 20, 2015Publication date: June 18, 2015Applicant: LITTELFUSE, INC.Inventors: Juergen Scheele, Julio Cesar Urrea, Kerri Michelle Hood
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Patent number: 9053844Abstract: An electrical device that includes a first electrode and a second electrode that are separated from one another so as to form a gap structure. A layer of protective material spans the gap structure to contact the first electrode and the second electrode. A dimension of the gap structure, corresponding to a separation distance between the first electrode and the second electrode, is varied and includes a minimum separation distance that coincides with a critical path of the layer of protective material between the first electrode and the second electrode.Type: GrantFiled: September 9, 2010Date of Patent: June 9, 2015Assignee: Littelfuse, Inc.Inventors: Lex Kosowsky, Robert Fleming
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Publication number: 20150155117Abstract: A switch is described. The switch may have first and second terminals to connect a source of power to a load, a shaft rotatable about a central axis and moveable longitudinally along the central axis, the shaft having a wing extending out orthogonally from the central axis, a contact plate to physically and electrically connect the first and second terminals when the shaft is moved longitudinally along the central axis, and a disengagement ramp to contact the wing when the shaft is rotated about the central axis, the disengagement ramp to force the shaft to move longitudinally along the central axis as the shaft is rotated to move the contact plate away from the first and second terminals.Type: ApplicationFiled: December 4, 2013Publication date: June 4, 2015Applicant: LITTELFUSE, INC.Inventor: Dana P. Scribner
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Patent number: 9048684Abstract: A transfer system may be provided. The transfer system may comprise a first transfer switch comprising first normally closed contacts and first normally open contacts. In addition, the transfer system may comprise a second transfer switch comprising second normally closed contacts and second normally open contacts. Furthermore, the transfer system may comprise third normally closed contacts with a solid state switch in parallel. A source monitor may be configured to monitor the quality of a primary source and a backup source. And a source control may be configured to operate the first transfer switch, the second transfer switch, the third normally closed contacts, and the solid state switch to transfer a load from the primary source to the backup source in response to the monitored quality of the primary source and the backup source.Type: GrantFiled: May 24, 2012Date of Patent: June 2, 2015Assignee: Littelfuse, Inc.Inventor: Kip McArthur Larson
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Publication number: 20150130438Abstract: An improved current limiting circuit comprising a switch having a first terminal and a second terminal, the first and second terminal configured to connect a power supply to a load. A first resistor connected in series between the first terminal and a first constant current source. A second resistor connected in series between the second terminal and a second constant current source. A control circuit configured to measure a voltage drop across the first resistor and compare the voltage drop to a voltage drop across the switch.Type: ApplicationFiled: November 13, 2014Publication date: May 14, 2015Applicant: LITTELFUSE, INC.Inventors: Sam S. Kang, John W. Jorgensen, Chad N. Marak
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Patent number: 9025296Abstract: A transient voltage suppressor may include a silicon controlled rectifier (SCR) having an anode coupled to Vcc. The SCR may include a PNP transistor (Q2) and an NPN transistor (Q3), the PNP transistor having a base in common with a collector of the NPN transistor and the PNP transistor having a collector in common with a base of the NPN transistor. The TVS may further include a Zener diode having an anode and cathode, wherein the anode is directly coupled to the base of the NPN transistor and/or the cathode is directly coupled to the base of the PNP transistor, and an additional NPN transistor (Q1). The cathode of the SCR may be directly coupled to a base of the additional NPN transistor, and a collector and emitter of the additional NPN transistor may be directly coupled in series between VCC and ground.Type: GrantFiled: January 5, 2012Date of Patent: May 5, 2015Assignee: Littelfuse, Inc.Inventors: John M. Jorgensen, Sam Kang, Chad N. Marak, James Lu
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Publication number: 20150116873Abstract: A circuit protection component including a crowbar device for protecting electronic devices from transients is generally disclosed. The circuit protection component may include a steering diode bridge and a crowbar device electrically connected to the steering diode bridge. The crowbar device may have a base and an emitter formed on a first layer, the first layer defining a breakdown voltage, which when exceeded allows current to pass under the emitter and out the device through a hole formed in the emitter.Type: ApplicationFiled: July 3, 2013Publication date: April 30, 2015Applicant: LITTELFUSE, INC.Inventors: Ader Shen, Ethan Kuo, Ting-Fung Cchang
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Publication number: 20150102896Abstract: A fuse including a fuse element, a diffusion layer, and a barrier layer is provided. The barrier layer acts to slow down and/or prevent premature diffusion of the diffusion material into the fuse element during normal operation. As a result, the fuse may be operated in environments having higher ambient temperatures and/or higher currents than otherwise possible. some examples provide a fuse including a fuse element formed from a first conductive material, the fuse element, a barrier layer disposed on a surface of the fuse element, the barrier layer including first and second portions separated by a gap, the barrier layer formed from a second conductive material different from the first conductive material, and a diffusion layer disposed in the gap on the surface of the fuse element, the diffusion layer formed from a third conductive material different from the second conductive material and first conductive material.Type: ApplicationFiled: October 11, 2013Publication date: April 16, 2015Applicant: LITTELFUSE, INC.Inventors: GORDON TODD DIETSCH, FRANCISCO URIBE, FREDERICK DELOS REYES, JOHN J. MONKOWSKI, JR.
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Patent number: 9007165Abstract: A substrate device includes an embedded layer of VSD material that overlays a conductive element or layer to provide a ground. An electrode, connected to circuit elements that are to be protected, extends into the thickness of the substrate to make contact with the VSD layer. When the circuit elements are operated under normal voltages, the VSD layer is dielectric and not connected to ground. When a transient electrical event occurs on the circuit elements, the VSD layer switches instantly to a conductive state, so that the first electrode is connected to ground.Type: GrantFiled: June 15, 2012Date of Patent: April 14, 2015Assignee: Littelfuse, Inc.Inventors: Lex Kosowsky, Robert Fleming, Bhret Graydon
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Patent number: 8976000Abstract: A blade fuse includes a first terminal includes an outer edge and an inner edge, the inner edge includes a first portion notched away from the inner edge beneath the first portion; a second terminal includes an outer edge and an inner edge, the inner edge include a second portion notched away from the inner edge beneath the second portion; an element extending from the first portion of the inner edge of the first terminal to the second portion of the inner edge of the second terminal; and a housing covering the element.Type: GrantFiled: November 2, 2011Date of Patent: March 10, 2015Assignee: Littelfuse, Inc.Inventors: Julio Urrea, James J. Beckert, Gary M. Bold, Seibang Oh, Juergen Scheele
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Patent number: 8968606Abstract: Various aspects provide for structures and devices to protect against spurious electrical events (e.g., electrostatic discharge). Some embodiments incorporate a voltage switchable dielectric material (VSDM) bridging a gap between two conductive pads. Normally insulating, the VSDM may conduct current from one pad to the other during a spurious electrical event (e.g., shunting current to ground). Some aspects include gaps having a gap width that is greater than 50% of a spacing between electrical leads connected to the pads. Some devices include single layers of VSDM. Some devices include multiple layers of VSDM. Various devices may be designed to increase a ratio of active volume (of VSDM) to inactive volume.Type: GrantFiled: March 25, 2010Date of Patent: March 3, 2015Assignee: Littelfuse, Inc.Inventors: Lex Kosowsky, Bhret Graydon, Robert Fleming
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Publication number: 20150055267Abstract: A normal relay emulator is described. The normal relay emulator may include a trigger circuit configured to detect a condition on a first power rail, the first power rail having a first voltage supply level. A boost converter electrically coupled to the first power rail and configured to boost the first voltage supply level to a second, higher, voltage supply level is provided. A bi-stable relay having a first terminal and a second terminal and an actuator electrically coupled to the boost converter and communicatively coupled to the trigger circuit is also provided. The actuator may be configured to energize the bi-stable relay using the second voltage supply level such that electrical contact between the first terminal and the second terminal changes between a first state and a second state based on the trigger circuit detecting the condition.Type: ApplicationFiled: August 21, 2013Publication date: February 26, 2015Applicant: LITTELFUSE, INC.Inventors: Chad Beauregard, Eric Graham
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Publication number: 20150054615Abstract: A convenient, cost-effective method for manufacturing low-current fuse elements. The method may include the steps of stamping a substrate out of a sheet of material and stamping at least one hole in the substrate. The method may further include the steps of bonding a layer of fuse material to a surface of the substrate with a portion of the fuse material covering the hole, stamping a fuse element out of the portion of fuse material covering the hole, and separating an individual fuse from the fuse material and the substrate. A low-current fuse can thereby be obtained using an easily performed stamping process.Type: ApplicationFiled: May 16, 2013Publication date: February 26, 2015Applicant: LITTELFUSE, INC.Inventors: James J. Beckert, Gregory G. Stumpo, Stephen R. Shierry
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Publication number: 20150048840Abstract: A device for monitoring a neutral grounding resistor (NGR), including first and second NGRs electrically connected in parallel, a rectifier circuit electrically connected in series with the second NGR and a voltage source and a logic resistor electrically connected in series with the second NGR. A logic circuit measures current passing through the logic resistor and determines the resistance of the first NGR based on the measured current and the resistance of the second NGR. As such, a failed-open or failed-short condition of the first NGR may be identified based at least in part on the determined resistance of the first NGR.Type: ApplicationFiled: April 11, 2013Publication date: February 19, 2015Applicant: LITTELFUSE, INC.Inventors: Michael P. Vangool, Geoffrey J. Baker
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Patent number: 8940193Abstract: One or more embodiments provide for a device that utilizes voltage switchable dielectric material having semi-conductive or conductive materials that have a relatively high aspect ratio for purpose of enhancing mechanical and electrical characteristics of the VSD material on the device.Type: GrantFiled: June 10, 2011Date of Patent: January 27, 2015Assignee: Littelfuse, Inc.Inventors: Lex Kosowsky, Robert Fleming