Current Responsive Patents (Class 361/57)
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Publication number: 20030072114Abstract: Compatibility with a current transformer having several kinds of rated current ratios is achieved by finding out a formula of relationship between errors arising in a transformer input circuit and detectable ranges set as setting values of the input circuits which can be optimally set. In connection with that, by dispensing with a gain control section, the number of components, the mounting area and the cost can be reduced. Arithmetic expressions representing the relationship among errors arising in the transformer input circuit, the instrumentation ranges of the input circuits, and detectable errors have been derived. Further by optimally setting the detectable ranges of the input circuits, which are the parameters of the arithmetic expressions, the configuration compatible with a current transformer having several kinds of rated current ratios is achieved.Type: ApplicationFiled: September 20, 2002Publication date: April 17, 2003Applicant: Hitachi,Ltd.Inventors: Daisuke Maeda, Takashi Funawatari, Yoshiyasu Watanabe
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Patent number: 6532405Abstract: An exemplary embodiment of the invention is a method for detecting a potentially locked axle on a vehicle propelled by an AC motor. The method includes conducting a speed test by estimating axle speed and comparing estimated axle speed to measured vehicle speed. The existence of a potential locked axle condition is determined based on the comparing of estimated axle speed to measured vehicle speed. Additional tests are disclosed for determining a potential locked axle condition and a sensor fault condition.Type: GrantFiled: August 9, 2000Date of Patent: March 11, 2003Assignee: General Electric CompanyInventors: Ajith Kuttannair Kumar, Jeffrey Louis Daigle
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Publication number: 20020181180Abstract: Over-current protection is accomplished in an output transistor (MP) of an electronic circuit wherein an input signal (Vgatedrive) Is Applying to a first conductor (19) coupled to a gate of the output transistor to cause an output current (Iout) to flow through the output transistor and an output terminal (11) of the electronic circuit. A limit voltage (VLIMIT) who is applied to an input (21) of a voltage clamping circuit (18) to cause a clamping current to flow in the first conductor (19) as needed to prevent the magnitude of the input signal (Vgatedrive) from being less than the magnitude of the limit voltage (VLIMIT) so that the output current (Iout) is limited to a maximum current limit determined by the limit voltage (VLIMIT).Type: ApplicationFiled: April 19, 2001Publication date: December 5, 2002Applicant: TEXAS INSTRUMENTS INCORPORATEDInventors: Vadim V. Ivanov, David R. Baum
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Publication number: 20020176217Abstract: The present invention relates to an overload protector structure of an extension cord receptacle that mainly comprised a fire wire conducting plate of a switching unit (or a receptacle unit) connected with an overload protector in the extension cord receptacle to extend properly; the overload protector has a housing member, a power input plate exposed at the said housing member, a temperature sensing plate is fixedly connected to an inner end of the power input plate, the said overload protector further penetrates outward through a slot channel from a contact point, the fire wire conducting plate can fitly extend into the said slot channel and contacts with the contact point of the temperature sensing plate; thereby, the effectiveness of rapid connection and eliminating the soldering joint point is possessed between the overload protector and the switch unit (or the receptacle unit).Type: ApplicationFiled: May 23, 2001Publication date: November 28, 2002Inventor: Chyong-yen Huang
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Patent number: 6452235Abstract: A floating body ESD protection circuit positioned between and coupled to an I/O pad and an internal circuit. A p-type depletion mode transistor is used to control the body of an n-type enhancement mode transistor. When the p-type depletion mode transistor is triggered, the body of n-type enhancement mode transistor remains grounded. If the p-type depletion mode transistor has not been triggered, the body remains in a floating state, lowering the range of the snapback voltage. As a consequence the ESD protection circuit is able to function more rapidly. Similarly, an n-type depletion mode transistor is used to control the body of a p-type enhancement mode transistor. When the n-type depletion mode transistor is triggered, the body remains coupled to a high voltage. If the n-type depletion mode transistor has not been triggered, the body is in a floating state. Thus, the range of the snapback voltage can be lowered, enabling the ESD protection circuit to function more rapidly.Type: GrantFiled: September 19, 2000Date of Patent: September 17, 2002Assignee: United Microelectronics Corp.Inventor: Liang-Choo Hsia
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Patent number: 6452771Abstract: A method and system for detecting a potentially destructive state of an arrangement containing electronics and for terminating the potentially destructive state. In the method and system currents consumed by the electronics through connecting mechanisms from at least one supply voltage are measured. The measured currents are compared with respective stored maximum permissible currents stored in a memory. Further, the connecting mechanisms are disconnected from the at least one supply voltage to thereby ground the arrangement when at least one consumed current is measured as higher than the respective maximum permissible current.Type: GrantFiled: June 13, 2000Date of Patent: September 17, 2002Assignee: Thales Nederland B.V.Inventor: Paulus Van Kempen
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Patent number: 6445276Abstract: A fuse apparatus (1) is provided for selectively interrupting a load current (Ia) flowing between a pair of associated conductor leads. The fuse apparatus includes at least two spaced apart electrically conductive contact elements (5) operatively connected with the associated conductor leads. A fuse element (7) is connected to the contact elements (5) using an electrically conductive connection material (9) to allow the current (Ia) to flow between the pair of associated conductor leads. The connection material (9) is adapted to electrically disconnect the fuse element (7) from the contact elements (5) when the current (Ia) exceeds a predetermined current intensity. The connection material (9) has an intrinsic electrical transition resistance characteristic whereby the material develops a temperature in proportion to an intensity of the current. The connection material melts as the current increases to separate the fuse element from the contact elements.Type: GrantFiled: March 4, 1999Date of Patent: September 3, 2002Assignee: TRW Automotive Electronics & Components GmbH & Co. KGInventors: Uwe Schön, Dieter Bornhorst, Joachim Korherr, Joachim Jüngst
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Publication number: 20020118496Abstract: A novel motor driver with an active snubber circuit. The motor driver is interposed between an external electrical power source and an electrical motor. The electrical motor is driven in first and second states such that the electrical motor produces an inductive flyback current when it switches torque direction. The motor driver comprises a reverse voltage protector in series between the power source and the electrical motor allowing flow of electrical power to the motor; and a capacitor arranged in parallel circuit with the motor between the motor and the diode (or other reverse voltage protector). The active snubber circuit is in parallel circuit with the motor between the diode and the electrical motor. The active snubber circuit comprises a switch having a sensor responsive to increases in the bus voltage resulting from the inductive flyback current and a resistor in series with the switch regulating electrical current flow.Type: ApplicationFiled: February 26, 2001Publication date: August 29, 2002Applicant: Woodward Governor CompanyInventor: David C. Petruska
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Patent number: 6349022Abstract: An overcurrent protection system gives rapid response to relatively small overcurrents has a sensor element and an interruption element in series between a power source and a load. The sensor element is functionally linked to the circuit interruption element via a control element. When current exceeds a predetermined amount, the sensor element transfers heat to the control element which causes the circuit interruption element to change from a conducting state to non-conducting fault state. A latching arrangement causes the protection system to remain in the non-conducting fault state until reset. The control element may include a PTC device or a bimetal switch.Type: GrantFiled: April 7, 2000Date of Patent: February 19, 2002Assignees: Tyco Electronics Corporation, EWD, L.L.C.Inventors: Inho Myong, Michael Brown, Douglas A. Burcicki, Glen A. DeGrendel
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Publication number: 20010033471Abstract: A current detection switch comprising a measured conductor into which a measured current flows, a plurality of magnetoelectric devices placed sandwiching the measured conductor so as to have magneto-sensitive faces on sides to which a magneticflux generated by the measured current is input, each of the magnetoelectric devices for outputting a magnetoelectric signal when the magnetic flux exceeds a predetermined value, and a computation section for outputting a logical multiplication of the magnetoelectric signals from the plurality of magnetoelectric devices as a detection signal.Type: ApplicationFiled: April 24, 2001Publication date: October 25, 2001Inventors: Mitsuaki Morimoto, Takashi Gohara, Yoshinori Ikuta, Yasuhiro Tamai
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Patent number: 6278381Abstract: A fault protective device (48) for limiting the maximum current and voltage applicable to electronic components and wiring (26, 30) located in the fuel tank (10) of an aircraft. Particularly, a fuel gauging system circuit (18) extends from a generator (20) located outside the tank to at least one probe (14) located in the tank and from the probe to instrumentation (24) outside the tank. The device is electrically coupled to the circuit at the tank wall (28) and includes a voltage clamp (50) and series inductor-capacitor resonant circuit (46), so that the resonant circuit provides a low series impedance when applied with a signal at the operating frequency of the input signal applied by the generator but provides a high series impedance when experiencing a signal of a different frequency indicative of a system fault.Type: GrantFiled: November 17, 2000Date of Patent: August 21, 2001Assignee: Smiths Aerospace, Inc.Inventor: Charles E. Bogert
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Publication number: 20010003500Abstract: Electrical protection device for a railroad vehicle, including electrical energy consuming units 6, 7 and electrical power supply means 1 to 5, electrical energy being supplied on at least two liner electrically separated from the ground formed by the vehicle as a whole, in particular its chassis and the electrically conductive parts connected to it. The electrical protection device includes detector means 50 for detecting a short circuit alternating current flowing from one of the two power supply lines to ground, to detect any short circuit between the other power supply line and ground.Type: ApplicationFiled: December 6, 2000Publication date: June 14, 2001Inventors: Alain Cheze, Bernard Macor
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Patent number: 6236546Abstract: A system is disclosed for verifying the operativeness of a crowbar circuit which normally protects an electrical device in a series circuit with a power supply. The crowbar circuit includes means for sensing fault current in the series circuit and a crowbar switch responds to the sensing means for protecting the electrical device by directing the fault current away from the electrical device. The system includes verification testing means including a fuse and actuatable pneumatic switch connected together in series for, when said pneumatic switch is actuated, providing a short circuit across the crowbar switch to verify the operativeness of the crowbar circuit which, if not operative, causes the fault current to flow through and blow out the fuse.Type: GrantFiled: August 16, 1999Date of Patent: May 22, 2001Assignee: Harris CorporationInventors: Joseph David Blickhan, James Bruce Pickard
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Patent number: 6178075Abstract: An electronic module comprising a power supply conductor coupled to one or more electromechanical actuators to supply operable power to the electromechanical actuators. The electronic module also includes a moisture sensor positioned to sense moisture intrusion into the module. Further, the electronic module comprises a first transistor responsively coupled to the moisture sensor, the first transistor coupled to draw current from the power supply conductor when the first transistor is in a conductive state. In addition, the electronic module includes a second transistor responsively coupled to the first transistor and in turn controllingly coupled to the first transistor.Type: GrantFiled: June 4, 1999Date of Patent: January 23, 2001Assignee: Visteon Global Technologies, Inc.Inventors: Mark Andrew Glinka Endicott, Vincent Colarossi, Viren Babubhai Merchant
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Patent number: 6094013Abstract: A circuit arrangement for limiting the current at make for a transformer wherein, in order to avoid the current peak at make when switching a transformer on, resistors are connected between operating voltage and the primary winding of the transformer. A test winding at the secondary side of the transformer is connected via a rectifier to the supply input of a contactor, so that the switches of the contactor close after the transformer is turned on and the resistors therefore no longer lie between operating voltage of the primary winding. PTC-resistors connected in series with the resistors assure that the resistors are not overloaded by the high-operating current of the transformer if the switches do not switch.Type: GrantFiled: December 2, 1998Date of Patent: July 25, 2000Assignee: Siemens AktiengesellschaftInventors: Hugo Goller, Klaus Hoffmann
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Patent number: 6031342Abstract: An electronic ballast for a fluorescent lamp which includes a frequency sweep circuit for driving a ballast controller IC at different operating frequencies depending on the operating mode of the fluorescent lamp. The sweep circuit monitors the operating mode of the lamp (e.g., preheat, ignite, running, shutdown) and automatically generates an appropriate variable voltage offset for controlling the lamp. The offset is added to a constant voltage supplied to an input of the ballast controller IC, resulting in a corresponding change in the frequency output by the ballast controller IC (and thus the lamp power). The electronic ballast also includes fault protection logic which monitors signals from the lamp resonant circuit and shuts down the ballast in the event of a fault condition. The fault protection logic also resets the frequency sweep circuit so that the lamp can restart automatically when the fault is corrected.Type: GrantFiled: February 12, 1998Date of Patent: February 29, 2000Assignee: International Rectifier CorporationInventors: Thomas J. Ribarich, John Parry
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Patent number: 6028470Abstract: An integrated circuit comprising a power transistor and a circuit arrangement. The circuit arrangement is thermally coupled to the power transistor and operates in a temperature-dependent fashion. The integrated circuit includes a pnp or npn transistor with a temperature dependent resistor coupled between the base and emitter of the transistor. The off-state current of the transistor changes as a function of temperature and initiates a change in a base current of the power transistor.Type: GrantFiled: October 14, 1997Date of Patent: February 22, 2000Assignee: Robert Bosch GmbHInventors: Hartmut Michel, Christian Pluntke
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Patent number: 5959816Abstract: A voltage regulator circuit includes a circuit input and a circuit output for coupling to a load. A circuit interrupt element is coupled between the input and the load for breaking the circuit between the input and the load. A sensing circuit coupled to the output senses when a signal applied to the load exceeds a defined limit. A trigger circuit coupled to the sensing circuit causes the circuit interrupt element to trip when the sensing circuit senses a signal which exceeds the defined limit.Type: GrantFiled: February 24, 1997Date of Patent: September 28, 1999Assignee: Anthony, Inc.Inventors: Gary Wood, Bernard Feldman
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Patent number: 5923515Abstract: A protection device for an electrical circuit comprises a housing assembly, a fuse support structure that is comprised of a conductive material and that can be coupled to the housing assembly, a main fuse that can be mounted to the fuse support structure to receive a flow of current therefrom and a trip fuse mechanically mounted to the main fuse by electrical contacts. The electrical contacts not only secure the trip fuse to the main fuse, but also provide a conductive path across the main fuse and through the trip fuse. In some embodiments, a momentary switch may be coupled to the trip fuse. In such instances, the trip fuse is configured to activate the momentary switch when a predetermined excessive current flows through the trip fuse and may be electrically connected to a current indicator that indicates when the excessive current flows through the trip fuse.Type: GrantFiled: January 27, 1998Date of Patent: July 13, 1999Assignee: Lucent Technologies Inc.Inventors: Gerald W. Eubanks, Michael C. Steeves
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Patent number: 5892647Abstract: An overcurrent detection circuit detects an overcurrent in a current path accurately and sensitively. The overcurrent detection circuit includes a first resistance element connected between first input and output terminals of the current path; a second resistance element connected to the first input terminal; a differential amplifying device connected to the first output terminal and the second resistance element; and a proportional-current output device connected to the second resistance element in series and to an output terminal of the differential amplifying device. The proportional-current output device receives an output signal from the differential amplifying device to output a proportional current with a magnitude proportional to a current flowing through the first resistance element.Type: GrantFiled: June 4, 1998Date of Patent: April 6, 1999Assignee: Fuji Electric Co., Ltd.Inventor: Kimiyoshi Mizoe
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Patent number: 5856902Abstract: The earth leakage breaker of the invention includes a first comparator; a second comparator connected to the first comparator; a third comparator having a threshold higher than the threshold of the first comparator for distinguishing a leakage current from the grounding current caused by a lightning surge or by the heavy ground fault; a monostable multivibrator triggered by the output of the third comparator for forming a time gate of a predetermined period; a counter for detecting a pulse outputted from the first comparator to distinguish whether the grounding current is caused by the lightning surge or by the heavy ground fault; and a trip signal generator circuit for outputting a trip signal in the case of leakage and heavy ground fault. The earth leakage breaker facilitates avoiding unnecessary breaking of the impulsive grounding current caused by the lightning surge.Type: GrantFiled: July 8, 1997Date of Patent: January 5, 1999Assignee: Fuji Electric Co., Ltd.Inventors: Takashi Hashimoto, Kiyoshi Tanigawa, Shoji Sasaki, Katsumi Watanabe
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Patent number: 5838043Abstract: A circuit for protecting a bonding pad of a semiconductor device from ESD voltages is located under the pad to permit the space otherwise used for a protection circuit to be used for normal operating components. The protection circuit has a compact layout that provides maximum ability to handle an ESD current within this limited space. The semiconductor structure for the circuit has separate parts for two SCR circuits, one for each polarity of ESD current. Each SCR circuit comprises two symmetrical SCR structures.Type: GrantFiled: April 29, 1997Date of Patent: November 17, 1998Assignee: United Microelectronics Corp.Inventor: Lee Chung Yuan
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Patent number: 5821740Abstract: A DC-to-DC converter includes a pulse width modulation circuit for modulating a switch to produce current pulses having at least a minimum pulse width to thereby control an output voltage to the load. The converter also includes a current limit determining circuit for determining when a desired peak current is no longer sufficient to maintain a desired output voltage thereby defining a current limit condition. In addition, the pulse width modulating circuit, when operating at the minimum pulse width, thereby defines a minimum pulse width condition. Accordingly, the converter preferably further includes an over-current determining circuit for determining an over-current condition responsive to the minimum pulse width condition being reached during a current limit condition. The converter may turn off the switch responsive to an over-current condition. A blanking signal may be used to clamp a comparator and established a minimum pulse width.Type: GrantFiled: February 14, 1997Date of Patent: October 13, 1998Assignee: Harris CorporationInventors: Robert G. Hodgins, Charles E. Hawkes, Michael M. Walters
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Patent number: 5805399Abstract: Apparatus for detecting series arcs and output load faults in high frequency luminous tube power supplies and ballasts including wideband ringing and detector circuits for collecting the intense high frequency, pre-plasma noise energy associated with the initial avalanche phase of high frequency arc formation and a transient suppressor for delaying the triggering of power supply shut-down for up to the duration of the arc avalanche phase. Plural detectors for increased sensitivity and reliability over a variety of arc locations may be employed. Dual purpose detector input probes serve as over-voltage corona generators.Type: GrantFiled: September 6, 1996Date of Patent: September 8, 1998Assignee: Everbrite, IncInventor: David R. Pacholok
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Patent number: 5757601Abstract: A short circuit protection system that reacts to a voltage across an electrical load to prevent overdissipation of a semiconductor switch in the event of a short circuit. The system includes a capacitor having a charge state. When the capacitor is charged, the electrical load is turned ON via a transistor. The system automatically latches the electrical load ON until a short circuit occurs or until the capacitor discharges. When a short circuit occurs, the system automatically turns the load OFF.Type: GrantFiled: January 21, 1997Date of Patent: May 26, 1998Assignee: Ford Motor CompanyInventor: Harold Ryan Macks
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Patent number: 5751051Abstract: A semiconductor device has a semiconductor chip which is divided into a plurality of separate regions. In each of these regions, there are provided a plurality of common discharge lines which are independent from one another, a plurality of first bonding pads which are connected directly to the respective common discharge lines, a plurality of second bonding pads which are not connected directly to the common discharge lines, a plurality of protective elements which are connected between the second bonding pads and the common discharge lines, and an inner lead for discharging which is directly connected to the first bonding pads and is bonded to a surface of the semiconductor chip. In all embodiments of the invention. More than one common discharge line is provided. This arrangement permits the reduction of the chip area thus enhancing design freedom and improving electrostatic breakdown characteristics.Type: GrantFiled: October 16, 1997Date of Patent: May 12, 1998Assignee: NEC CorporationInventor: Kiminori Hayano
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Patent number: 5737170Abstract: The base of a thermal shutdown bipolar transistor having a V.sub.BE(on) which decreases with increasing temperature is biased with a bias voltage V.sub.PTATbias which increases proportionally with increasing absolute temperature. By supplying the base of the thermal shutdown transistor with a bias voltage V.sub.PTATbias which increases with increasing temperature rather than a bias voltage that remains constant or decreases with increasing temperature, the temperature at which the thermal shutdown transistor turns on is made more predictable and the thermal shutdown transistor is made to turn on more sharply at a desired thermal shutdown temperature. The bias voltage V.sub.PTATbias may be generated by driving a current which increases proportionally with increasing absolute temperature across a resistor. Current sources employing feedback control loops are disclosed for generating such a current. Startup current sources are disclosed for starting control loop operation.Type: GrantFiled: September 27, 1994Date of Patent: April 7, 1998Assignee: Micrel, Inc.Inventor: James C. Moyer
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Patent number: 5723960Abstract: An opening/closing control apparatus detects an overload placed on a movable member of a vehicle such as a sunroof and a power window while it is sliding. Further, it prevents overload detecting operation (reversing motion) from being made by a cause other than an overload. A control processor circuit compares a driving current value of a motor detected at predetermined intervals with a preset current value and corrects an overload threshold value to a threshold value of higher value when the driving current value detected when a first predetermined time period has passed after the start of the motor does not exceed the preset current value. Thereafter, the control processor circuit determines that an overload has occurred when a change in the driving current value has exceeded the overload threshold value.Type: GrantFiled: August 8, 1995Date of Patent: March 3, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Kouichi Harada
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Patent number: 5710689Abstract: A protection circuit prevents snapback events in MOS transistors associated with semiconductor or micromechanical structures, such as ink-jet ejectors. A bulk electrode associated with the MOS transistor is monitored for unusual high voltages which are consistent with an impending snapback event. The voltage on the bulk electrode is then used to turn on the control transistor which connects the gate of the MOS transistor to ground and thereby protects the device.Type: GrantFiled: June 24, 1996Date of Patent: January 20, 1998Assignee: Xerox CorporationInventors: Juan J. Becerra, Sophie V. Vandebroek
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Patent number: 5703746Abstract: Wiring harnessess are current feedback paths from the loads to a battery, thereby forming a closed-circuit. For each load, there are provided a current detector and a current control; each current detector compares the current input to a junction box to the output current from the corresponding load via a corresponding wiring harness, and outputs a normal state signal when the two currents are equal. When the input and output currents are at variance with each other, it outputs an abnormal state signal. Each current controller causes, upon receipt of the normal state signal, the input current to flow into the corresponding load along normal current path; upon receipt of the abnormal state signal, the input current is directed to flow to a current cutoff which includes a thermal device which is disposed in parallel with the current path and whose resistance value changes with temperature, thereby cutting off the flow of current to the load.Type: GrantFiled: February 16, 1996Date of Patent: December 30, 1997Assignee: Sumitomo Wiring Systems, Ltd.Inventors: Takahiro Onizuka, Yuuji Saka
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Patent number: 5672918Abstract: A "blink" technique, analogous to a person blinking at a flash of bright light, is provided for mitigating the effects of single event current latchup and prompt pulse destructive radiation on a micro-electronic circuit. The system includes event detection circuitry, power dump logic circuitry, and energy limiting measures with autonomous recovery. The event detection circuitry includes ionizing radiation pulse detection means for detecting a pulse of ionizing radiation and for providing at an output terminal thereof a detection signal indicative of the detection of a pulse of ionizing radiation. The current sensing circuitry is coupled to the power bus for determining an occurrence of excess current through the power bus caused by ionizing radiation or by ion-induced destructive latchup of a semiconductor device.Type: GrantFiled: August 18, 1994Date of Patent: September 30, 1997Assignee: The United States of America as represented by the United States Department of EnergyInventors: Joseph Robert Kimbrough, Nicholas John Colella
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Patent number: 5670936Abstract: A power controller (10) for supplying power to a power distribution network (N) in which power from a polyphase source (G) is routed to using equipment (E) connected to the network through the power controller. A plurality of solid-state power devices (82) switch each separate phase of the polyphase power to the equipment. A firing circuit (14) controls gating of the switches to route the power. Fuses (F) are connected between the switches and the using equipment to interrupt power flow to the equipment if excessive current begins to be drawn. A con, roller (20) controls a shutdown sequence employed by the controller to eliminate current spiking at shutdown. The various components are housed in an enclosure (22) which includes a mounting structure (56) for mounting the aforesaid components. A cooling system (26) employs a fan (88) for directing air flow through the mounting structure to cool the components.Type: GrantFiled: April 26, 1995Date of Patent: September 23, 1997Assignee: Emerson Electric Co.Inventors: Wayne S. Estes, Carl D. Russell
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Patent number: 5640293Abstract: A high-current, high-voltage solid state switch includes at least one solid state switching component connected to control circuitry configured into a single package. In the preferred embodiment, the switching component includes a power field effect transistor, and the control circuitry includes control logic, temperature sense and overcurrent circuits supported in an adjacent, coplanar relationship. Parallel coupled transistors are used for higher current embodiments.Type: GrantFiled: November 10, 1993Date of Patent: June 17, 1997Assignee: Ice CorporationInventors: William H. Dawes, Arthur R. Vaughan
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Patent number: 5629824Abstract: The Hall-Effect Arc Protector is used to protect sensitive electronics from high energy arcs. The apparatus detects arcs by monitoring an electrical conductor, of the instrument, for changes in the electromagnetic field surrounding the conductor which would be indicative of a possible arcing condition. When the magnitude of the monitored electromagnetic field exceeds a predetermined threshold, the potential for an instrument damaging are exists and the control system logic activates a high speed circuit breaker. The activation of the breaker shunts the energy imparted to the input signal through a dummy load to the ground. After the arc condition is terminated, the normal signal path is restored.Type: GrantFiled: July 27, 1993Date of Patent: May 13, 1997Assignee: The United States of America as represented by the United States Department of EnergyInventors: Richard A. Rankin, Dale K. Kotter
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Patent number: 5606482Abstract: A solid state circuit breaker which provides high voltage isolation between a control circuit and a power source is described. The circuit breaker comprises a receiver for providing a control signal in response to a transmitter that is electrically isolated from the receiver, a solid state switch that closes in response to the control signal thereby allowing a load current to flow through the switch, a current sensor for measuring the load current, and an inhibit circuit responsive to the current sensor for inhibiting the control signal when the load current exceeds a predetermined magnitude thereby opening the switch without adjusting the transmitter. After opening the switch, the inhibit circuit is responsive to the transmitter for allowing the control signal thereby closing the switch.Type: GrantFiled: April 14, 1995Date of Patent: February 25, 1997Assignee: Lucent Technologies Inc.Inventor: Steven B. Witmer
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Patent number: 5587862Abstract: A Ground Fault Interrupter ("GFI") combined with a plug-receiving receptacle is mounted on a plastic bucket. The bucket is additionally configured with a weathertight opening through which a three prong male end of a pigtail electrically connected to the GFI/receptacle unit may pass. A resealable lid provides a weathertight covering for the bucket so that the combination is functional during field use or for final storage for user transport of tools and other electrical apparatus. The device is optionally configured with a removable, storable, pedestal pole-mounted light assembly. A pedestal light support flange is attached to the interior base of the bucket, and container-sized pole sections substantially the same interior clearance height of the container are available for assembling the light pole when needed by a user. The light is powered by the GFI/receptacle unit carried by the bucket.Type: GrantFiled: July 13, 1995Date of Patent: December 24, 1996Inventor: William D. Frank, Sr.
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Patent number: 5587864Abstract: A three-phase electrical system includes an interrupt controller. The interrupt controller protects against inadvertent current flow between a phase conductor and ground and between phase conductors. The interrupt controller measures the voltage across a series connection of current transformers disposed about various phase conductors. If an inadvertent current path exists between one of the phase conductors and ground or between two of the phase conductors, the interrupt controller interrupts the current flow in the phase conductors. Additionally, a single-phase electrical system with a hot conductor and a neutral conductor includes an interrupt controller. The interrupt controller protects against inadvertent current flow between the hat conductor and ground and between the hot conductor and the neutral conductor. The interrupt controller measures the voltage across a series connection of current transformers disposed about the hot and neutral conductors.Type: GrantFiled: April 11, 1994Date of Patent: December 24, 1996Assignee: Ford Motor CompanyInventors: Allan R. Gale, Craig B. Toepfer
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Patent number: 5574378Abstract: A non-ferrous current sensor is used to continuously measure the charging current magnitude in step-graded foil and paper insulation systems and capacitive insulation systems used on high voltage measurement and control apparatus such as instrument transformers and on the condenser bushings of power transformers and circuit breakers. The low voltage measured signal is conditioned by an electronic circuit such that it modulates a DC signal in a system current control loop to provide continuous remote monitoring and alarm functions. Remote power is supplied to the sensor and conversion circuits through the current loop. The sensor detects changes in the charging current through the insulation ground conductor, indicating the degradation of the dielectric properties between the foil layers. The sensor and associated electronic circuitry are enclosed in a housing adaptable to be used with a capacitance tap common to high voltage measurement and control apparatus.Type: GrantFiled: December 15, 1994Date of Patent: November 12, 1996Assignee: Square D CompanyInventors: Thomas J. Meyer, Nicholas S. Powers
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Patent number: 5537026Abstract: A power controller (10) and a method for supplying power to a power distribution network (N) in which power from a polyphase source (G) is routed to using equipment (E) connected to the network through the power controller. A plurality of solid-state power devices (82) switch each separate phase of the polyphase power to the equipment. A firing circuit (14) controls gating of the switches to route the power. Fuses (F) are connected between the switches and the using equipment to interrupt power flow to the equipment if excessive current begins to be drawn. Circuit breakers (74) are connected between the power source and the switches to interrupt current flow to the equipment if excessive current is drawn. A control unit (20) controls operation of the controller. The firing circuit includes a master firing unit (164a) and a slave firing unit (164b).Type: GrantFiled: April 26, 1995Date of Patent: July 16, 1996Assignee: Emerson Electric Co.Inventors: Wayne S. Estes, Carl D. Russell
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Patent number: 5526216Abstract: In a circuit configuration for the shutoff of a semiconductor component in the event of excess current, the semiconductor component has gate and cathode terminals and is controlled by the field effect. A controllable switch is connected between the gate and cathode terminals and is made conducting by a control signal. A device controls the controllable switch to a range of high on-state DC resistance when there is excess current and a shutoff signal is simultaneously present.Type: GrantFiled: September 9, 1994Date of Patent: June 11, 1996Assignee: Siemens AktiengesellschaftInventors: Sven Konrad, Klaus Reinmuth, Hans Stut
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Patent number: 5519264Abstract: A method and apparatus for preventing current inrush upon the application of power to a load includes the steps of applying a first increasing DC voltage from a voltage source to the load through a negative temperature coefficient device having a first terminal coupled to the voltage source and a second terminal coupled to the load and after a preselected period of time, bypassing said first and second terminals via a bypass circuit and coupling the increasing voltage to the load through the bypass circuit.Type: GrantFiled: March 27, 1995Date of Patent: May 21, 1996Assignee: EMC CorporationInventors: Christopher A. Heyden, Donald R. Watson
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Patent number: 5485342Abstract: An abnormal current cut off circuit for creating a circuit break when an abnormal current flows in a circuit such as a print head driver circuit for a printer. When a driver section 3 is being driven by a power supply circuit 1, the power supply is provided to a driver circuit 2 which drives the driver section 3 via a transistor 5 which is connected in the power supply line and which is turned on by a transistor 7. When the device goes into a standby state, the transistor 5 is turned off, so that the current is supplied to the carriage motor a and the Line feed motor b within the driver section 3 via the fuse 4 and the diode 6 which are connected in parallel with the transistor 5. If an abnormal current then flows during the standby state, the fuse 4 will be broken, and transistor 7 will be turned off so that transistor 5 will also be turned off which ensures that the power supply line is cut completely.Type: GrantFiled: July 28, 1993Date of Patent: January 16, 1996Inventors: Koichi Sugino, Nobuhiro Michimoto
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Patent number: 5424898Abstract: A drive circuit for the interior, and one or more of the exterior, mirrors in a vehicle mirror system provides a drive signal to each of the mirrors to establish the reflectance level of that mirror. Circuit protection is provided to sense a fault condition on one of the electrical conductors extending to the exterior mirrors and to take corrective action in response to a fault condition. The circuit protection may also respond to a fault condition in the electrical supply of the drive circuit and take suitable corrective action. In certain embodiments, each mirror in the mirror system is responsive to one of a plurality of output amplifiers, which is responsive to a distinct desired reflectance signal level in order to color that mirror to a reflectance level that is distinct from that of the other mirrors.Type: GrantFiled: August 8, 1994Date of Patent: June 13, 1995Assignee: Donnelly CorporationInventors: Mark L. Larson, Desmond J. O'Farrell
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Patent number: 5420396Abstract: A heating apparatus comprising a heating member, energization element for energizing said heating member, a temperature detection member for detecting a temperature of said heating member, a first switching element for turning on/off energization by said energization means on the basis of the temperature detected by said temperature detection member, abnormal current detection element for detecting an abnormal current flowing through said heating member, a second switching element for turning off energization by said energization element, and energization stop member for operating said second switching element to turn off energization.Type: GrantFiled: February 26, 1992Date of Patent: May 30, 1995Assignee: Canon Kabushiki KaishaInventors: Toshiyuki Itoh, Toshihiko Inuyama, Takeji Gima, Hiroshi Hashimoto, Hiromichi Yamanaka, Masanori Ishizu
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Patent number: 5414586Abstract: A superconducting current limiting device for limiting overcurrent flowing in a load. The device includes a current limiter with a first superconducting coil, a second superconducting coil arranged coaxially with the first superconducting coil so as to have a negative magnetic coupling condition, and a third superconducting coil arranged coaxially with the first and second superconducting coils so as to have a negative magnetic coupling condition with the second superconducting coil and so as to have a positive magnetic coupling condition with the first superconducting coil. The first and second superconducting coils are electrically connected in series. The device includes a high speed switch connected electrically in series with the third superconducting coil to form a series circuit. The series circuit is electrically connected in parallel with the second superconducting coil.Type: GrantFiled: April 20, 1993Date of Patent: May 9, 1995Assignee: Kabushiki Kaisha ToshibaInventors: Tsukushi Hara, Takeshi Ohkuma, Kazuyuki Tsurunaga, Daisuke Ito, Takamitsu Tada
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Patent number: 5394287Abstract: A TSD (8) is provided in the vicinity of an IGBT (1), and reference voltages (VR1 to VR5) are provided to the negative inputs of comparators (51 to 55) as a function of a temperature detection signal (S8). A sense terminal (3) of the IGBT is connected to the positive inputs of the comparators (51 to 55) in common. An output signal (S51) of the comparator (51) and output signals (S72 to S75) of signal judging circuits (72 to 75) having received the output signals (S52 to S55) are applied to the input of an NOR gate (6) for on/off control of the IGBT. The signal judging circuits (72 to 75) normally output an L-level judgment signal (S7) and output an H-level judgment signal (S7) when the input signal is at the H level for periods of time that are not shorter than allowable durations (.DELTA.t2 to .DELTA.t5 ), respectively. This provides an overcurrent protective device for a power device which performs overcurrent protective operation adapted for a practical safe operating area of the power device.Type: GrantFiled: January 29, 1993Date of Patent: February 28, 1995Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hiroshi Sakata, Masanori Fukunaga
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Patent number: 5285346Abstract: A control circuit for protecting a power device has been provided. The control circuit has a thermal shutdown circuit for activating a first SCR when the temperature of the control circuit exceeds a predetermined temperature. Additionally, the control circuit has a DSAT detection circuit for activating the first SCR in response to an external signal. The first SCR is coupled across an input terminal and the common terminal of the control circuit. When the first SCR latches, it functions to subsequently latch a second SCR that is coupled across the output and common terminals. The second SCR functions to rapidly discharge the voltage appearing across the output and common terminals.Additionally, the control circuit includes an input level sensitive circuit which may be utilized to deactivate various circuitry depending upon the current level of an input signal supplied to the control circuit.Type: GrantFiled: December 13, 1991Date of Patent: February 8, 1994Assignee: Motorola, Inc.Inventors: Robert B. Davies, David F. Mietus, Paul T. Bennett
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Patent number: 5162965Abstract: A high-speed high-voltage FET current interrupter which opens the cathode circuit of microwave tubes when internal tube arcing occurs. By removing the detrimental fault current which causes degradation to the microwave tube body and grid, the longevity of the microwave tube and the pulse energy storage capacitor is greatly increased over those transmitters which use dissipative crow bar circuits. Even more important is that the transmitter reset time after an arc occurs is orders of magnitude faster than transmitters using crow bars or primary power interrupters when arcing occurs--an important feature when engaged in a "dog fight".Type: GrantFiled: June 28, 1991Date of Patent: November 10, 1992Assignee: The United States of America as represented by the Secretary of the Air ForceInventors: Walter E. Milberger, Franklin B. Jones, Charles S. Kerfoot
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Patent number: 5150286Abstract: The invention icludes a device for protecting electronic circuitry from damage, especially damage resulting from high neutron flux density produced by a nuclear explosion. The invention protects the circuitry by disabling its power supply system upon detection of the nuclear event. The power supply system is disabled both by short-circuiting the main power supply, which provides control voltages to various subsidiary powert supplies, and by short-circuiting all the output filter capacitors in the system, which may have a substantial residual charge. The invention periodically and automatically attempts to re-start the power supply system, but the system can be re-started only if the nuclear event detector is not actuated. The circuit made according to the invention is entirely analog, and therefore does not depend, for its operation, on the continued functioning of the circuitry to be protected.Type: GrantFiled: March 12, 1991Date of Patent: September 22, 1992Assignee: Performance Controls, Inc.Inventors: Joseph G. Venditto, Jr., James P. Detweiler
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Patent number: 5119262Abstract: A protection circuit against an excessive current in a flyback transformer which supplies a high voltage to a CRT. A fuse and current detecting resistor are inserted on the line which supplies a current to the primary winding of the flyback transformer. The intermediate point of the primary winding and the node of the fuse and current detecting resistor are connected by a semiconductor switching element which becomes conductive when the voltage across the current detecting resistor reaches a certain high voltage. Accordingly, if an excessive current flows in the flyback transformer, the thyristor turns on, causing the fuse to be blown by the large current, whereby the current supply to the flyback transformer can be shut off.Type: GrantFiled: July 26, 1989Date of Patent: June 2, 1992Assignee: Murata Mfg. Co., Ltd.Inventor: Hiroshi Ikeuchi