Patents Assigned to Littelfuse, Inc.
  • Intelligent high speed automatic transfer switch
    Patent number: 9048684
    Abstract: 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: Grant
    Filed: May 24, 2012
    Date of Patent: June 2, 2015
    Assignee: Littelfuse, Inc.
    Inventor: Kip McArthur Larson
  • Transient voltage suppressor
    Patent number: 9025296
    Abstract: 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: Grant
    Filed: January 5, 2012
    Date of Patent: May 5, 2015
    Assignee: Littelfuse, Inc.
    Inventors: John M. Jorgensen, Sam Kang, Chad N. Marak, James Lu
  • Substrate device or package using embedded layer of voltage switchable dielectric material in a vertical switching configuration
    Patent number: 9007165
    Abstract: 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: Grant
    Filed: June 15, 2012
    Date of Patent: April 14, 2015
    Assignee: Littelfuse, Inc.
    Inventors: Lex Kosowsky, Robert Fleming, Bhret Graydon
  • Blade fuse
    Patent number: 8976000
    Abstract: 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: Grant
    Filed: November 2, 2011
    Date of Patent: March 10, 2015
    Assignee: Littelfuse, Inc.
    Inventors: Julio Urrea, James J. Beckert, Gary M. Bold, Seibang Oh, Juergen Scheele
  • Components having voltage switchable dielectric materials
    Patent number: 8968606
    Abstract: 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: Grant
    Filed: March 25, 2010
    Date of Patent: March 3, 2015
    Assignee: Littelfuse, Inc.
    Inventors: Lex Kosowsky, Bhret Graydon, Robert Fleming
  • Electronic device for voltage switchable dielectric material having high aspect ratio particles
    Patent number: 8940193
    Abstract: 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: Grant
    Filed: June 10, 2011
    Date of Patent: January 27, 2015
    Assignee: Littelfuse, Inc.
    Inventors: Lex Kosowsky, Robert Fleming
  • Solderless surface mount fuse
    Patent number: 8937524
    Abstract: A surface mount fuse in one embodiment includes an insulative body, first and second conductive and caps attached to the insulative body, each end cap defining an aperture, and a fuse element extending (i) through the insulative body and the apertures and (ii) along outside surfaces of the first and second conductive end caps in such a way that solder used to attach the first and second conductive end caps to an external medium also fastens the fuse element to the first and second end caps.
    Type: Grant
    Filed: March 25, 2009
    Date of Patent: January 20, 2015
    Assignee: Littelfuse, Inc.
    Inventors: Conrado de Leon, Gordon T. Dietsch, Edgardo Olan, John Emannuel Semana, John Song, Stephen J. Whitney
  • LAMINATED ELECTRICAL FUSE
    Publication number: 20140266564
    Abstract: A compact, high breaking capacity fuse that includes a top insulative layer, at least one intermediate insulative layer, and a bottom insulative layer arranged in a vertically stacked configuration. The at least one intermediate layer may have a hole formed therethrough that defines an air gap within the fuse. A first conductive terminal may be formed on a first end of the fuse and a second conductive terminal may be formed on a second end of the fuse. At least one fusible element may connect the first terminal to the second terminal, thus providing an electrically conductive pathway therebetween. A portion of the at least one fusible element may pass through the air gap defined by the hole in the at least one intermediate insulative layer.
    Type: Application
    Filed: March 14, 2013
    Publication date: September 18, 2014
    Applicant: Littelfuse, Inc.
    Inventors: Albert Enriquez, Demetrio Criste, Conrado DeLeon, Crispin Zulueta, Roel Retardo, John Semana, Gordon Todd Dietsch
  • Integrated fuse status indication in an open fuse block
    Patent number: 8810420
    Abstract: An open fuse block is provided having a visual indicator or light assembly connected in parallel with a replaceable fuse mounted in the fuse block. When the fuse is blown, the corresponding visual indicator is illuminated to identify the blown fuse, thereby facilitating quick and easy replacement of the fuse. Since the visual indicator is connected in parallel with the fuse element, when the fuse is blown, the fuse results in an open circuit and the flow of electricity is rerouted through the visual indicator. The visual indicator is thereby illuminated and the corresponding blown fuse can be easily identified. The visual indicator or light assembly can include, for example, a neon bulb, light emitting diode, fluorescent bulb, incandescent bulb, or any other visual indicator that emits light.
    Type: Grant
    Filed: February 28, 2012
    Date of Patent: August 19, 2014
    Assignee: Littelfuse, Inc.
    Inventors: Daniel F. Stanek, Nathan C. Siegwald, Thomas M. Novak, Christopher J. Miller, Daniel R. Gilman, William F. Gonzalez, Jesse D. Rednour
  • Intelligent fuse holder and circuit protection methods
    Patent number: 8762083
    Abstract: An intelligent circuit protection system and method for automating component replacement and providing information to a user or operator about a load for circuit protection. The circuit protection method includes sensing current and voltage across a fuse protecting a load; sending at least one signal indicative of the current and voltage; and using the at least one signal to determine if the load is operating normally.
    Type: Grant
    Filed: July 28, 2008
    Date of Patent: June 24, 2014
    Assignee: Littelfuse, Inc.
    Inventors: William G. Rodseth, Daniel Stanek, Daniel Gilman
  • Formulations for voltage switchable dielectric materials having a stepped voltage response and methods for making the same
    Patent number: 8723153
    Abstract: Formulations for voltage switchable dielectric materials include two or more different types of semiconductive materials uniformly dispersed within a dielectric matrix material. The semiconductive materials are selected to have different bandgap energies in order to provide the voltage switchable dielectric material with a stepped voltage response. The semiconductive materials may comprise inorganic particles, organic particles, or an organic material that is soluble in, or miscible with, the dielectric matrix material. Formulations optionally can also include electrically conductive materials. At least one of the conductive or semiconductive materials in a formulation can comprise particles characterized by an aspect ratio of at least 3 or greater.
    Type: Grant
    Filed: April 14, 2012
    Date of Patent: May 13, 2014
    Assignee: Littelfuse, Inc.
    Inventors: Lex Kosowsky, Robert Fleming
  • Moderately hazardous environment fuse
    Patent number: 8674803
    Abstract: A fuse for a moderately hazardous environment comprising: (i) a fuse element; (ii) first and second terminals connected to the fuse element; and (iii) a metal enclosure placed around the fuse element, the enclosure configured to protect the environment from an opening of the fuse element, and wherein the first and second terminals extend from the metal enclosure.
    Type: Grant
    Filed: October 26, 2009
    Date of Patent: March 18, 2014
    Assignee: Littelfuse, Inc.
    Inventors: Daniel Stanek, Daniel Gilman, Nathan Siegwald, William G. Rodseth
  • Fuse assembly
    Patent number: 8669840
    Abstract: A circuit protection assembly employs a post arrangement that is easier to manufacture and has a built-in insulating fuse configuration. The circuit protection assembly is disposed between a source of power and a circuit to be protected. The circuit protection assembly includes comprises a mounting block having a bore extending therethrough and a recess cavity on a first surface of the mounting block. A post having a first end is disposed within the recess cavity and a body portion extends through the bore. A fuse having a centrally disposed aperture is configured to receive the body portion of the post. The post has a second end configured to receive a terminal for connection to a circuit to be protected.
    Type: Grant
    Filed: May 17, 2011
    Date of Patent: March 11, 2014
    Assignee: Littelfuse, Inc.
    Inventors: Julio Urrea, Gary M. Bold
  • Metal film surface mount fuse
    Patent number: 8659384
    Abstract: A chip fuse includes a plurality of parallel fusible link layers disposed between a corresponding plurality of insulating glass layers deposited on a substrate and laminated together. The fusible link layers are interconnected between the glass layers without the need for vias. A first of the plurality of fusible link layers extends beyond a cover disposed over the chip fuse and one of the glass layers to form a first electrical terminal connection. Another of the plurality of the fusible link layers also extends beyond the cover and another of the glass layers to form a second electrical terminal connection.
    Type: Grant
    Filed: September 15, 2010
    Date of Patent: February 25, 2014
    Assignee: Littelfuse, Inc.
    Inventors: G. Todd Dietsch, Olga Spaldon-Stewart
  • Low voltage PNPN protection device
    Patent number: 8557640
    Abstract: A low voltage protection device that includes a silicon substrate comprises an inner layer of a first dopant type. The device also includes a first outer layer of a second dopant type disposed adjacent a first surface of the inner layer and a second outer layer of the second dopant type disposed adjacent a second surface of the inner layer opposite the first surface. The device further includes a first mesa region disposed in a peripheral region of a first side of the low voltage protection device. The first mesa region includes a first area that includes a peripheral portion of a cathode of the low voltage protection device, the cathode formed by diffusing a high concentration of dopant species of the first type on a first surface of the silicon substrate, and a second area comprising a high concentration of diffused dopant species of the second type.
    Type: Grant
    Filed: February 1, 2013
    Date of Patent: October 15, 2013
    Assignee: Littelfuse, Inc.
    Inventors: Richard Rodrigues, Johnny Chen, Ethan Kuo
  • Circuit protection device
    Patent number: 8531263
    Abstract: A circuit protection device includes a conductive layer which is connected to first and second terminals. A spring is electrically connected to the first and 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 of the ends of the spring thereby releasing the spring to create an open circuit.
    Type: Grant
    Filed: November 23, 2010
    Date of Patent: September 10, 2013
    Assignee: Littelfuse, Inc.
    Inventors: G. Todd Dietsch, Olga Spaldon-Stewart, Stephen Whitney
  • Fusible substrate
    Patent number: 8525633
    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.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: September 3, 2013
    Assignee: Littelfuse, Inc.
    Inventors: Stephen J. Whitney, William Travis, Jeffrey P. Youngblood, Sarah M. Book, Edward D. Barriball, Milea J. Kittle
  • LOW VOLTAGE PNPN PROTECTION DEVICE
    Publication number: 20130164923
    Abstract: A low voltage protection device that includes a silicon substrate comprises an inner layer of a first dopant type. The device also includes a first outer layer of a second dopant type disposed adjacent a first surface of the inner layer and a second outer layer of the second dopant type disposed adjacent a second surface of the inner layer opposite the first surface. The device further includes a first mesa region disposed in a peripheral region of a first side of the low voltage protection device. The first mesa region includes a first area that includes a peripheral portion of a cathode of the low voltage protection device, the cathode formed by diffusing a high concentration of dopant species of the first type on a first surface of the silicon substrate, and a second area comprising a high concentration of diffused dopant species of the second type.
    Type: Application
    Filed: February 1, 2013
    Publication date: June 27, 2013
    Applicant: Littelfuse, Inc.
    Inventor: Littelfuse, Inc.
  • SCR circuit for protecting central office end of telephone line
    Patent number: 8451576
    Abstract: A protection circuit employing a pair of SCR devices connected respectfully from telephone line tip conductor and ring conductors to ground. The SCR devices are of the type providing internal semiconductor resistors between the gate and cathode terminals for sensing overcurrents in the telephone line conductors, and providing voltage sensitive semiconductor regions so that the SCR devices are sensitive to overvoltages on the telephone line conductors. A pair of diodes are connected across the cathode-anode terminals of the SCR devices to provide overvoltage protection for positive polarity overvoltages on the telephone line.
    Type: Grant
    Filed: May 30, 2008
    Date of Patent: May 28, 2013
    Assignee: Littelfuse, Inc.
    Inventor: Kelly C. Casey
  • Low voltage PNPN protection device
    Patent number: 8384126
    Abstract: A low voltage protection device that includes a silicon substrate comprises an inner layer of a first dopant type. The device also includes a first outer layer of a second dopant type disposed adjacent a first surface of the inner layer and a second outer layer of the second dopant type disposed adjacent a second surface of the inner layer opposite the first surface. The device further includes a first mesa region disposed in a peripheral region of a first side of the low voltage protection device. The first mesa region includes a first area that includes a peripheral portion of a cathode of the low voltage protection device, the cathode formed by diffusing a high concentration of dopant species of the first type on a first surface of the silicon substrate, and a second area comprising a high concentration of diffused dopant species of the second type.
    Type: Grant
    Filed: June 20, 2011
    Date of Patent: February 26, 2013
    Assignee: Littelfuse, Inc.
    Inventors: Richard Rodrigues, Johnny Chen, Ethan Kuo