Switch Or Relay Patents (Class 340/644)
  • Patent number: 5774323
    Abstract: An electromagnetic switch for opening and closing a set of contacts has a microprocessor which monitors coil current to determine the state of the contacts. The switch relies on the phenomenon that the inductance of the switch coil changes significantly between the open position of the contacts when the switch armature carrying the moveable contact is spaced by an air gap from the core of the electromagnet, and the closed position in which the armature abuts the core. For an AC energized coil, which is self-limiting in that the increase in inductance from closing of the contacts reduces the current to the holding value automatically, a coil current of less than about one/half of the nominal open contact value is an indication that the contacts are closed.
    Type: Grant
    Filed: October 31, 1995
    Date of Patent: June 30, 1998
    Assignee: Eaton Corporation
    Inventors: Mark E. Innes, John H. Blakely
  • Patent number: 5764152
    Abstract: An energization indicator for a solenoid includes an electrically operable signaler (70) having a coil (72) for energizing the signaler (70) when a magnetic flux field sweeps such coil, with the coil (72) being mounted in the magnetic flux path of the solenoid coil. The indicator includes the hold-down member (116) for rotatable positioning of the bobbin assembly on the hold-down member independently of the rotated position of the hold-down member to locate the lamp as desired on the solenoid.
    Type: Grant
    Filed: January 29, 1997
    Date of Patent: June 9, 1998
    Assignee: Detroit Coil Company
    Inventor: Albert L. Kozleski
  • Patent number: 5763961
    Abstract: The electronic switching device serves to control the connection of a load to a voltage source by a switch which is controlled in a first operating mode directly by a binary signal furnished by a signal processing circuit and in a second operating mode inverted. The switching device has three terminals, of which the first permanently remains connected to a first terminal of the voltage source and to a first terminal of the load, whilst of the other two switching device terminals the one is connected to the second terminal of the voltage source and the other to the second terminal of the load. The switching device is configured so that it can be changed over from the one operating mode into the other by interchanging the connections between these two other switching device terminals and the second terminals of the voltage source and of the load, respectively.
    Type: Grant
    Filed: September 19, 1996
    Date of Patent: June 9, 1998
    Assignee: Endress+Hauser GmbH+Co.
    Inventors: Volker Dreyer, Bernd Strutt
  • Patent number: 5747984
    Abstract: Switching components with contact parts that are mounted on a contact carrier in a switch housing may include devices for monitoring the contact erosion. The contact carrier may be split (sub-divided) and contact parts can be slotted at the rear and mounted on the sub-divided contact carrier. Thus, the oscillation response (vibration response) of the contact carrier in particular can be used as a measure of the erosion of the contact parts.
    Type: Grant
    Filed: September 22, 1995
    Date of Patent: May 5, 1998
    Assignee: Siemens Aktiengesellschaft
    Inventors: Dietrich Amft, David-Walter Branston, Jorg Kieser, Reinhard Maier
  • Patent number: 5739419
    Abstract: An apparatus for monitoring the vacuum of a vacuum switch having at least one vacuum switch tube with a switch chamber and switch contacts is provided. The apparatus has a remotely interrogatable pressure measurement sensor in the form of a piezocrystal or surface acoustic (SAW) device arranged in the interior of the vacuum switch tube and a remote interrogation device placed external to the vacuum switch for monitoring the vacuum via the sensor.
    Type: Grant
    Filed: August 9, 1996
    Date of Patent: April 14, 1998
    Assignee: Siemens Aktiengesellschaft
    Inventors: Reinhard Maier, Wolf-Eckhart Bulst, Thomas Ostertag, Oliver Sczesny
  • Patent number: 5699030
    Abstract: An electromagnetic relay, such as an electromechanical RF switch, which is operated by an electromagnetic coil, is provided with an indicating circuit which responds to the position of the electromagnetic armature as well as the application of driving current to the coil. A magnetically activated reed switch is mounted adjacent to the electromagnetic coil at a distance selected so that the magnetic field of the coil will operate the reed switch when current is applied to the coil and the armature is driven into a position closing a magnetic circle.
    Type: Grant
    Filed: April 4, 1996
    Date of Patent: December 16, 1997
    Assignee: The Narda Microwave Corporation
    Inventors: Vincent Leikus, Yuly Bauer
  • Patent number: 5663712
    Abstract: An electrical contact position indicator assembly is operatively coupled to an electrical device, such as a recloser, for indicating the relative position of the contacts of the electrical device, i.e., opened or closed, at any given time during operation of the electrical device. The position indicator assembly includes a movable indicator having first indicia to indicate that the contacts are opened, and second indicia to indicate that the contacts are closed. Each of the first and second indicia of the indicator lies in more than one plane. Preferably, each of the first and second indicia of the indicator lies on a three-dimensional, curvilinear or spherical surface. In the preferred embodiment, the indicator includes a mechanical linkage to the contact opening and closing assembly.
    Type: Grant
    Filed: January 5, 1995
    Date of Patent: September 2, 1997
    Assignee: Hubbell Incorporated
    Inventor: Eugene L. Kamp
  • Patent number: 5648722
    Abstract: An apparatus and method for determining the state of a switch for use in an HVAC system. The apparatus and method are advantageously configured for use within a heating, ventilation and air conditioning (HVAC) system, in which the sensing of the state of safety switches external to a controller is desirable. A current sensor coupled in series between a current source, a safety switch, and a current load, detects the flow of current from the current source and through the switch and load. A status signal, indicative of the flow of current through the current sensor, is generated for sampling by a microprocessor. The presence or absence of current flow through the current sensor provides an indication as to whether the remotely-located switch is in an open or closed state.
    Type: Grant
    Filed: July 28, 1995
    Date of Patent: July 15, 1997
    Assignee: Gas Research Institute
    Inventors: Nir Merry, Jack Francis Hammons
  • Patent number: 5646599
    Abstract: The duty ratio range of a duty signal DCN transmitted from a high-voltage load controller 12 to a field current controller 103 is divided into several subranges, which are assigned to zones, such as a normal voltage control zone, high-voltage control zone, and power generation stop and failure signal zone. The duty signal of a duty ratio in each zone is transmitted to the field current controller 103 for controlling the power generation mode of a generator 2. When a failure in a high-voltage circuit 16 is detected, the duty signal of a duty ratio in the power generation stop and failure signal zone causes power generation of the generator to stop and a pilot lamp 10 to go on for warning. The pilot lamp 10 is also used to warn the operator to a power generation error of the generator 2.
    Type: Grant
    Filed: August 3, 1995
    Date of Patent: July 8, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Katsumi Adachi
  • Patent number: 5644730
    Abstract: A binary sensor including a binary sensing circuit, a logic circuit and an adaptive interface card adapted to matingly engage the binary sensor. The binary sensing circuit and logic circuit are operatively coupled for communication with external circuits. The adaptive interface card includes bus network interface circuitry that disables the logic circuit and enables the bus network interface circuitry upon matingly engaging the interface card with the binary sensor. The bus network interface circuitry also becomes operatively coupled with the sensing circuit upon matingly engaging the adaptive interface card with the binary sensor. The bus network interface circuitry of the adaptive interface card provides a means for the binary sensor to communicate with bus networks.
    Type: Grant
    Filed: March 22, 1995
    Date of Patent: July 1, 1997
    Assignee: Banner Engineering Corp.
    Inventor: Robert W. Fayfield
  • Patent number: 5623254
    Abstract: A drive circuit fault detection device comprising a discriminating circuit generating a digital signal, the level of which indicates a fault; and an identifying circuit generating a binary-coded signal indicating the type of fault, i.e. ground shorting of the drive circuit or an open load. The discriminating circuit comprises a resistive network connected to the output of the drive circuit, for generating a voltage indicating correct connection of the load or a fault on the drive circuit and a comparator for comparing the generated voltage with a reference voltage and supplying the digital signal at its output. The identifying circuit comprises a current mirror circuit generating an output voltage having two different logic levels in the event of short circuiting or an open load, respectively, and a combination circuit for generating the binary-coded output signal.
    Type: Grant
    Filed: January 3, 1995
    Date of Patent: April 22, 1997
    Assignee: SGS-Thomson Microelectronics S.r.l.
    Inventors: Massimiliano Brambilla, Giampietro Maggioni
  • Patent number: 5614888
    Abstract: A circuit configuration for a signalling device in circuit breaker units, in particular in power circuit breakers, which have an electronic tripping device and which become effective in the event of a fault in an electrical system to be protected, whereby the electronic tripping device includes a microcontroller which performs a fault evaluation, and for each type of fault makes available an output pin, from which the corresponding fault signal is amplified and transmitted to an electrical relay. The fault signal (FM, FM1 . . . FMn) is transmitted to the circuit configuration (SA, SA1 . . . SAn), and by means of logic operation with the action of a static standard signal and of a clock pulse signal (Clock Pulse) acts on the electrical relay, which is realized in the form of a bistable relay (RB, RB1 . . . RBn) the contact system of which corresponds to a make function or a break function, depending on the signal status of the standard signal.
    Type: Grant
    Filed: March 3, 1995
    Date of Patent: March 25, 1997
    Assignee: Klockner-Moeller GmbH
    Inventors: Oliver Borchmann, Thomas Bungartz
  • Patent number: 5585678
    Abstract: A device for monitoring the switch position of a switch including an auxiliary voltage source, which is connected to the switch, a device for converting the switch position into an electrical signal, a device for transmitting the electrical signal and a device for evaluating the transmitted information. The converting device uses a pulse-duration modulation, the duty cycle of which becomes higher as the voltage U.sub.0 of the auxiliary voltage source becomes smaller. This enables the monitoring device to be used for different auxiliary voltages, without any need for adaptation.
    Type: Grant
    Filed: April 8, 1994
    Date of Patent: December 17, 1996
    Assignee: ABB Management AG
    Inventors: Ron Dijk, Markus Meng
  • Patent number: 5559438
    Abstract: A composite switch is constituted by a series or parallel association of at least two simple switches. Each simple switch includes an element for measuring the current in the simple switch in the case of a parallel association; an element for measuring the voltage across the simple switch in the case of an association in series; and a control circuit receiving the information provided by the measuring elements as well as a control signal from the simple switch, and providing an active failure signal if the measured voltage is high or the measured current is low while the simple switch is controlled to be turned on, or if the measured current is high or the measured voltage is low while the simple switch is controlled to be turned off.
    Type: Grant
    Filed: January 25, 1995
    Date of Patent: September 24, 1996
    Assignee: Sextant Avionique
    Inventors: Bernard Bedouet, Christophe Taurand
  • Patent number: 5555456
    Abstract: A fault control apparatus is disclosed having elements that provide for an easily reconfigurable fault response. When the fault detection circuit signals that a fault has occurred, an alarm is triggered, switching means are automatically set to their fault positions, and a control output circuit is activated. The flexibility of fault response is made possible by the use of a matrix of switched connections to preset the fault positions of the relays. Additional flexibility is provided by providing an adjustable level for the control output.
    Type: Grant
    Filed: August 2, 1994
    Date of Patent: September 10, 1996
    Assignee: ITT Corporation
    Inventor: Eugene L. Waite
  • Patent number: 5546002
    Abstract: In order to provide a dependable check on the reliable functioning of contacts of switches or relays which control a control device, to ascertain whether they occupy the desired rest contact position and/or have a sufficiently high mains voltage, the rest contacts of the two switches can be connected in parallel by way of a respective electrical resistor to a pole of the voltage source and both resistors can be connected in series to a charging capacitor which, upon the attainment of a given electrical charge or voltage (threshold voltage) activates the control device and in particular feeds a threshold switch or itself serves as such.
    Type: Grant
    Filed: November 18, 1993
    Date of Patent: August 13, 1996
    Assignee: Landis & Gyr Business Support AG
    Inventor: Erich Hickl
  • Patent number: 5543997
    Abstract: A safety switching arrangement for the switching on and off of the power supply (11) of two actors (12a, 12b) for example relays, which, in dependence on the switching on of the current, and in dependence on a sensor switching signal (13a, 13b) jointly set a working apparatus (22) in operation, the safety switching arrangement comprising two main switches (14a, 14b) arranged between the power supply (11) and each preferably earthed actor (12a, 12b).
    Type: Grant
    Filed: December 15, 1993
    Date of Patent: August 6, 1996
    Assignee: Erwin Sick GmbH, Optik-Elektronik
    Inventor: Harald Ruprecht
  • Patent number: 5536142
    Abstract: An off state demonstrating device on a line-pulling switch for a ceiling fan, is characterized in that a display or demonstrating device is jumper connected at the off position of the switch, so that when the switch is in an off state, the display or demonstrating device can be turned on and a user can be advised that the ceiling fan is in an off state.
    Type: Grant
    Filed: January 4, 1995
    Date of Patent: July 16, 1996
    Inventor: Frank Hsieh
  • Patent number: 5530299
    Abstract: A method for determining mechanical parameters of an electric switching device exposed to environmental influences in which a measuring transmitter is provided for detecting the speed of a component of the drive means of the switch device at at least two consecutive times. In the case of vacuum power switches, the time of contact of the switch members and the time of the latching in the switched-on condition are preferably considered. If measurement values from comparative measurements of a given number of switches are available, the maximum intensity of a given environmental influence at which test sample can reliably operate is determined from a measurement of a test sample under normal environmental conditions.
    Type: Grant
    Filed: May 16, 1994
    Date of Patent: June 25, 1996
    Assignee: Siemens Aktiengesellschaft
    Inventors: Bernd Besslein, Jurgen Nutzel, Werner Reinert, Peter Zinn
  • Patent number: 5506573
    Abstract: A method for sensing the on/off status condition of a power switch in an appliance includes applying a series of alternating current (AC) voltage pulses to an appliance with an on/off switch that are synchronized to a source of AC power, sensing the presence of any series of AC current pulses that result if said appliance switch is closed, analyzing any AC current pulses detected in the step of sensing to determine if they resulted from the application of the AC voltage in the step of applying, and outputting an on/off status indication for the appliance switch.
    Type: Grant
    Filed: June 21, 1994
    Date of Patent: April 9, 1996
    Assignee: Server Technology, Inc.
    Inventors: Carrell W. Ewing, Andrew J. Cleveland
  • Patent number: 5506508
    Abstract: In one aspect of the present invention, an apparatus detects a shorted winding condition of a solenoid coil. The apparatus includes a reference solenoid that is connected to a test solenoid. A sine generator drives the reference solenoid with a sinusoidal waveform to cause an induced voltage across the test solenoid. A meter determines the voltage difference between the solenoids and compares the voltage difference to a predetermined value.
    Type: Grant
    Filed: June 12, 1995
    Date of Patent: April 9, 1996
    Assignee: Caterpillar Inc.
    Inventor: Daniel E. Zimmermann
  • Patent number: 5497093
    Abstract: Electrical and mechanical operation of a bistable magnetically latching solenoid is diagnosed by monitoring induced voltage across the one of a pair of solenoid coils not energized. Energization of one of the pair of coils induces voltage across the other of the coils not energized and plunger actuation in response to energization induces another voltage therethrough. The various induced voltages are distinguishable as between those caused by energization of a coil or motion of the plunger.
    Type: Grant
    Filed: May 2, 1994
    Date of Patent: March 5, 1996
    Assignee: General Motors Corporation
    Inventors: Arthur R. Sundeen, James C. Byrne, Vincent A. Cichosz
  • Patent number: 5487013
    Abstract: The operating parameters of a proximity switch can differ depending on the type of switch and also because of manufacturing tolerances. To make it possible for one to react to new developments in ultrasonic transducers and to customer-specific solutions without requiring additional space, data such as operating parameters are able to be input into a microprocessor of a prefabricated proximity switch with little expenditure of time and energy. A proximity switch may contain an enabling input and an overcurrent-detection device including a microprocessor. An overcurrent across the switching output can be identified by a pulse provided to a first input of the microprocessor. A programming device is provided through which such an overcurrent condition is simulated and the corresponding pulse is generated which represents information about an operating parameter in the form of a bit pattern. The microprocessor is loaded with this bit pattern.
    Type: Grant
    Filed: March 10, 1995
    Date of Patent: January 23, 1996
    Assignee: Siemens Aktiengesellschaft
    Inventor: Ernst Luber
  • Patent number: 5455733
    Abstract: A circuit which gives a continuous voltage output indication of whether a contact is open or closed. The circuit senses the voltage across the contact to detect whether the contact is open or closed. When there is a significant voltage, the circuit indicates that the contact is open. When the voltage is negligible, the circuit indicates that the contact is closed. Alternatively, the current through the contact can be sensed to provide an indication of whether the contact is conducting or not. The circuit can be used to indicate the welding close of a relay contact in which case power to the load can be turned off or the contact can be opened by other than normal corrective actions. One application is to discontinue closing movement of a garage door when the motor relay switch does not open as desired, but there are innumerable other applications.
    Type: Grant
    Filed: June 27, 1994
    Date of Patent: October 3, 1995
    Assignee: GMI Holdings, Inc.
    Inventor: Dennis W. Waggamon
  • Patent number: 5451879
    Abstract: An improved monitoring system which identifies the particular event (contact operation) and therefore the particular electromechanical relay (20, 22, and 24 which operated). This information is output from a MCU (30), along with the relative time the event occurred, to a PC and an LCD display (40). In addition, the relative occurrence time is recorded to the thousandths of a second.
    Type: Grant
    Filed: August 14, 1992
    Date of Patent: September 19, 1995
    Inventor: Clayton K. Moore
  • Patent number: 5434558
    Abstract: An annunciator for indicating the removal of an electrical plug from the electrical receptacle. The electrical receptacle includes neutral switching contacts actuated in response to the insertion of a plug into the receptacle. An input circuit in the annunciator apparatus monitors the state of the neutral switching contacts and couples signals produced when a plug is removed to a latching circuit thereby to produce an audible or electrical indication of plug removal. The input Circuit and latching circuit are electrically isolated, and the annunciator detects any attempts to disconnect the apparatus from an external power supply or to remove any internal battery.
    Type: Grant
    Filed: January 21, 1993
    Date of Patent: July 18, 1995
    Inventor: Abraham Zeder
  • Patent number: 5420571
    Abstract: A monitoring device is provided for use in association with a limit switch or similar mechanically actuated device in order to permit its end of life to be predicted. The system uses nonvolatile random access memory to store a count which represents the number of occurrences of one of two alternative events. The first event is the occurrence of a number of switch actuations and the second event is the lapse of a predetermined period of time. When either of these two events occurs, a microprocessor increments a count in the nonvolatile memory unit and clears both the clock and the volatile memory parameter. When the number stored in the nonvolatile memory represents a number of actuations estimated to be appropriately equal to the total life of the switch, this condition can be signaled to a sensor bus by a communication circuit. Alternatively, a light emitting diode can be alternately energized and de-energized to represent the number of actuations having exceeded the predicted end of life total.
    Type: Grant
    Filed: January 11, 1994
    Date of Patent: May 30, 1995
    Assignee: Honeywell Inc.
    Inventors: Mark L. Coleman, Thomas A. Fletcher, Lyle D. Johnsen
  • Patent number: 5415053
    Abstract: An apparatus for testing an industrial machine safety system that allows the machine to begin operation only when a plurality of safety push buttons have all been depressed, and that stops the machine's operation when any safety push button is released. The apparatus includes an artificial hand that can depress and, upon command, release one of the safety push buttons, and has a release detector for detecting the release of the artificial hand. The release detector operates optically. A lamp directs a light beam along a path that is blocked by a plunger when releasing the safety push button and not blocked when depressing the safety push button. A photodetector detects interruption of this light beam. Thus release of the safety push button is detected upon detection of interruption of the light beam. The machine begins to stop upon release of the safety push button. A motion detector detects the stoppage of the machine.
    Type: Grant
    Filed: August 21, 1992
    Date of Patent: May 16, 1995
    Assignee: Patriot Sensors and Controls
    Inventor: Leonard W. Elias
  • Patent number: 5398025
    Abstract: An improved input module is able to sense the ON and OFF states associated with an external signal, wherein that signal complies with standards denoting the ON and OFF condition thereof. The improved input module includes a fixed impedance and a parameter sensor, such as a voltage sensor, which senses at least a portion of the voltage drop across the impedance. In addition, the module includes a current limiter in series with the impedance so as to limit the current flow through the impedance when the threshold parameter has been exceeded. An additional embodiment of the input module includes a second current limiter which is able to selectively detect broken wires associated with the connection of the external signal to the input module.
    Type: Grant
    Filed: November 10, 1992
    Date of Patent: March 14, 1995
    Assignee: Modicon, Inc.
    Inventor: Jerard I. Herman
  • Patent number: 5374922
    Abstract: A device for determining the state of an apparatus capable of existing in a first state and a second state. The apparatus is provided with auxiliary contacts (CAO1, . . . , CAF1, . . . ) which provide binary state signals that depend on the current state of the apparatus. The device includes at least one first state auxiliary contact CAO1), that provides a "1" state signal when the apparatus is in its first state, and at least one second state auxiliary contact CAS1) providing a "1" state signal when the apparatus is in its second state. The device also has a programmed microcontroller (MP) having inputs on which it receives the state signals from the auxiliary contacts (CAO1, . . . , CAF1, . . . ) and also instructions (OO, OF) requesting the apparatus to switch from one state to the other.
    Type: Grant
    Filed: October 14, 1992
    Date of Patent: December 20, 1994
    Assignee: GEC Alsthom SA
    Inventor: Gerard Ebersohl
  • Patent number: 5353014
    Abstract: A circuit breaker arranged with overload sensing, switches and LED indicators. Provided is a green LED (42) which when lit indicates that the circuit is blown and so the electrical wires from the breaker are not powered--the wires are "dead"; a red LED is also provided to indicate, when lit, that the electrical wires are powered or "live", in addition there is an amber third LED (52) which, when lit, indicates that a short circuit overload is still connected to the breaker output terminals.
    Type: Grant
    Filed: April 27, 1992
    Date of Patent: October 4, 1994
    Inventors: John T. Carroll, Raymond W. Dunbrack
  • Patent number: 5351038
    Abstract: A circuit breaker locator comprises a housing having a plunger projecting outwardly at one end and reciprocably moveable within the housing. The plunger is coupled to a spring urged retractable contact at the opposite end of the housing. The housing also includes, at the end with the retractable contact, a pair of contacts extending outwardly therefrom which are coupled to a fuse and a pilot light connected in parallel with the fuse. In operation, the pair of contacts are inserted into an electrical outlet and the plunger is actuated forcing the retractable ground contact into the outlet. The device automatically trips a circuit breaker related to the particular outlet so that it is possible to check which circuit breaker is connected to the outlet. If the breaker fails to trip, the alarm light, which is connected parallel with the fuse, is activated indicating a faulty circuit breaker. The circuit breaker locator provides a ready and safe means of determining what circuit breaker is related to what outlet.
    Type: Grant
    Filed: December 28, 1992
    Date of Patent: September 27, 1994
    Inventor: Arnold Goldberg
  • Patent number: 5345181
    Abstract: A circuit is provided for detecting abnormal conduction of current conducted through a solenoid in response to the pulse width modulation signal. The circuit includes a measuring means, for detecting conduction current conducted through the solenoid in response to the pulse width modulation signal and measuring continuous conduction time of the conduction current, and determining means, for determining a conduction to be an abnormal conduction when the continuous conduction time is longer than a predetermined time. Thus, the circuit can be miniaturized and the accuracy of the circuit is not affected by the accuracy of its components. And, the circuit is capable of detecting the half short state of the transistor driving the solenoid and not malfunctioning even if tile power is turned off.
    Type: Grant
    Filed: July 16, 1992
    Date of Patent: September 6, 1994
    Assignee: Yamaha Corporation
    Inventors: Rokurota Mantani, Yasutoshi Kaneko, Takashi Tamaki
  • Patent number: 5345225
    Abstract: A tamper detection system for promptly warns a utility that it has lost control of a load which is part of a load management system, and may be giving price incentives to a customer without receiving the corresponding benefit arising from the intended control of the load. A monitor circuit automatically determines whether the load management device is connected to the load by detecting whether a current is passing via the load control device to the load, and generates a warning signal when no current is detected for a first predetermined period of time. The load current is detected either by inductively coupling a conductor to the load with a sensing conductor, or by sensing current induced in the load control relay as the load current passes through the relay contacts. The tamper detection feature operates without any activity of the load management device, and detects disconnection of the load even when the load management device itself is powered up and working properly.
    Type: Grant
    Filed: October 30, 1992
    Date of Patent: September 6, 1994
    Assignee: Scientific-Atlanta, Inc.
    Inventor: Glenn A. Davis
  • Patent number: 5341029
    Abstract: The invention relates to a method for the supervision of a switch, in which a switch supervision signal (CA1, CA2, CB1, CB2) is generated and transmitted to the switch contact to be supervised, and in which the switch supervision signal (CA1, CA2, CB1, CB2) returning from the switch contact is detected and compared with the emitted signal. A coded signal is used as switch supervision signal (CA1, CA2, CB1, CB2) and this coded signal is transmitted serially to the switch contact to be supervised.
    Type: Grant
    Filed: December 13, 1990
    Date of Patent: August 23, 1994
    Assignee: Erwin Sick GmbH Optik-Elektronik
    Inventor: Darrell E. Johnson
  • Patent number: 5304935
    Abstract: Load driver system (10) preferably uses a microprocessor controller (20) to generate write/read signals and command signals received by a circuit at write/read and command/status input terminals (16, 17). The circuit (15) responds to the input signals and controls a semiconductor switch (11) that controls the operative state of a load (14). The circuit (15) includes a load shorted high detector (28), a load shorted low detector (29) and a load open detector (30) which are used to detect various faults and provide a predetermined sequence of logic states at the command/status input terminal (17) during read cycles implemented by the controller (20). Thus one input line (terminal 17) is used to both send commands to the semiconductor switch (11) and receive a sequence of logic states indicative of various fault modes. This permits the controller to determine which of several types of faults, if any, has occurred, while minimizing the number of controller-circuit interconnections.
    Type: Grant
    Filed: December 17, 1991
    Date of Patent: April 19, 1994
    Assignee: Motorola, Inc.
    Inventors: William M. Rathke, Jean M. Villevieille, William J. McGraw
  • Patent number: 5289131
    Abstract: A circuit configuration is provided for monitoring an electromagnetically actuated device, such as an electromagnetic clutch. The circuit comprises a switchable power source connected to the winding of the electromagnet; the power source supplies a composite voltage formed of a direct voltage part and a periodic alternating voltage part superimposed on one another. Engage and disengage signals are issued for the clutch and the direct voltage part assumes distinctly different levels in dependence on the engage and disengage signals. A precision resistor is connected in series with the winding of the electromagnet and a voltage sensor is connected at a node between the winding and the precision resistor. An evaluation circuit is connected to the voltage sensor for evaluating the alternating voltage part acting on the precision resistor and receiving therefrom information regarding the functionality of the electromagnetic device.
    Type: Grant
    Filed: September 10, 1992
    Date of Patent: February 22, 1994
    Assignee: Heidelberger Druckmaschinen AG
    Inventors: Heinrich Heidt, Ulf Delang
  • Patent number: 5287087
    Abstract: An energization indicator for a solenoid includes an electrically operable signaler (70) having a coil (72) for energizing the signaler (70) when a magnetic flux field sweeps such coil, with the coil (72) being mounted in the magnetic flux path of the solenoid coil (53).
    Type: Grant
    Filed: June 15, 1992
    Date of Patent: February 15, 1994
    Assignee: Detroit Coil Company
    Inventors: David C. Jencks, Larry A. Williamson
  • Patent number: 5258744
    Abstract: An annunciator for indicating the removal of an electrical plug from an electrical receptacle. The electrical receptacle includes neutral switching contacts actuated in response to the insertion of a plug into the receptacle. An input circuit in the annunciator apparatus monitors the state of the neutral switching contacts and couples signals produced when a plug is removed to a latching circuit thereby to produce an audible or electrical indication of plug removal. The annunciator circuit does not provide an alarm in response to the insertion of a plug or to an absence of a plug.
    Type: Grant
    Filed: July 5, 1991
    Date of Patent: November 2, 1993
    Inventor: Abraham Zeder
  • Patent number: 5256973
    Abstract: A computerized relay tester is provided which comprises a bar code reader, a test circuit for determining an actual value of an operational characteristic of the relay, and a memory for storing reference values for the operational characteristic for a plurality of relays. The test circuit is operative to automatically measure the actual voltage or current values at which "pickup" or "drop away" occurs in the relay under test, by sensing an inductive voltage "spike" caused by movement of the relay armature. Based on signals from the bar code reader, a reference value for the particular operational characteristic under test are retrieved from memory. The actual value is then compared with the reference value to determine whether the relay is functioning properly, and the relay tester outputs an indication of the operational state or condition of the relay.
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: October 26, 1993
    Inventors: Michael Thee, William Shurmantine
  • Patent number: 5243291
    Abstract: A circuit is provided for detecting the deposition of an electromagnetic contactor which opens and closes a drive circuit connecting a power source to a load. A load current of the drive circuit and an operating current for operating the electromagnetic contactor are detected and applied to a detection circuit. The thus detected load current and operating current are used to determine the deposition of the electromagnetic contactor. Further, in the event of a detected malfunction in the electromagnetic contactors, a breaker of the drive circuit is automatically opened.
    Type: Grant
    Filed: October 11, 1991
    Date of Patent: September 7, 1993
    Assignee: Shinkoh Electric Co., Ltd.
    Inventor: Heihachiro Umemura
  • Patent number: 5243296
    Abstract: When a solenoid has been turned on by supplying current to a coil thereof, the solenoid operation is checked by temporarily ceasing the supply of current to the coil to temporarily deenergize the solenoid. The current flowing in the coil is detected while the solenoid is temporarily deenergized, and the characteristics of the thus detected current are used to discriminate the position of a movable iron core of the solenoid. On the other hand, when the solenoid has been turned off by ceasing the supply of current to the coil, the solenoid operation is checked by temporarily supplying current to the coil to thereby temporarily energize the solenoid. The current flowing in the coil while the solenoid is temporarily energized is detected, and the characteristics of the thus detected coil current are used to determine the position of the movable iron core of the solenoid.
    Type: Grant
    Filed: October 18, 1991
    Date of Patent: September 7, 1993
    Assignee: Tokimec Inc.
    Inventors: Tsuyoshi Ando, Toshibumi Kakinuma, Tomokazu Kominami, Kazuyuki Kihara, Kousuke Hatakenaka, Akio Mito
  • Patent number: 5227729
    Abstract: A fusion detecting system for relays is provided for detecting a fusion of relay contacts. Two fully-interlocked or semi-interlocked relays are connected in such a manner that they operate under identical conditions, and a fused state is detected based on the states of signals sent from series-connected make contacts and series-connected break contacts of the two relays. In the case of semi-interlocked relays (R1, R2), if a make contact (r12) is fused during a current supply to a coil, the other contact (r22) remains in an open state or at a make-contact side after the current supply to the coil is cut off, and if a break contact (r11) is fused, the other contact (r21) remains in an open state or at break-contact side after a current is supplied to the relay coil.
    Type: Grant
    Filed: April 15, 1991
    Date of Patent: July 13, 1993
    Assignee: Fanuc Ltd
    Inventor: Yoshinori Hoshino
  • Patent number: 5223821
    Abstract: In a triac power switching system, two triacs are connected in series between an AC power source and a load. Each time power is applied to a load, the triacs are tested by first turning on one of the triacs while maintaining the other triac turned off, then turning on both triacs to apply power to the load for a set time interval and then turning off one of the triacs and determining whether power is still applied to the load. If power is applied to the load while either one of the triacs is supposed to be off, an alarm is sounded. In addition, if power is not applied to the load when both triacs are turned on, an alarm is sounded.
    Type: Grant
    Filed: October 28, 1991
    Date of Patent: June 29, 1993
    Assignee: Forney International, Inc.
    Inventors: Eric L. Poe, Billy R. Slater
  • Patent number: 5214595
    Abstract: An abnormality diagnosing system and method for high voltage power apparatus wherein a plurality of detectors for detecting abnormalities of the high voltage power apparatus and providing outputs indicative thereof are disposed to detect predetermined phenomena indicative of at least an insulation abnormality, power supply abnormality, and foreign matter among abnormalities existing inside of the high voltage power apparatus. A monitoring arrangement responsive to the outputs of the detectors provides at least one of an output and display of the kind of abnormality detected.
    Type: Grant
    Filed: November 7, 1991
    Date of Patent: May 25, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Jun Ozawa, Fumihiro Endo, Youichi Ohshita, Izumi Yamada, Tokio Yamagiwa, Hiroshi Yamada, Mitsuo Sawairi, Hashime Nagai
  • Patent number: 5202589
    Abstract: The switch condition of two switches (S1, S2) connected in parallel to a single transmission line (11) is detected by the signals output from two Schmitt triggers (10a, 10b) which are arranged to operate at different switching threshold levels by virtue of the output (WA) of one of the triggers (10a) being connected to the threshold level control input (F) of the other trigger (10b). Closure of one of the switches (S1 or S2) causes a reference voltage (UR) to the applied to the inputs of the triggers (10a, 10b) which is turn causes the upper threshold trigger (10a) to operate. Closure of both switches (S1 and S2) reduces the level of the voltage applied to the inputs of the triggers which is turn causes the lower threshold trigger to operate. Preferably, the signal input to the lower threshold trigger is converted into a current prior to application to the trigger due to the relatively small difference in threshold levels.
    Type: Grant
    Filed: September 13, 1990
    Date of Patent: April 13, 1993
    Assignee: Robert Bosch GmbH
    Inventor: Klaus Huser
  • Patent number: 5200737
    Abstract: A system and method for detecting partial discharge of gas-insulated switchgear wherein a high-frequency component and the fundamental wave component of the voltage applied to the conductor of the gas-insulated switchgear are detected, the zero-cross point of the fundamental wave component is set as the starting point for the voltage, and the presence of partial discharge and the reason for the occurrence of partial discharge are ascertained based on the phase difference between the phase of the detected high-frequency component and the phase of the starting point of the voltage.
    Type: Grant
    Filed: November 29, 1991
    Date of Patent: April 6, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Katsumi Konishi, Takaaki Sakakibara
  • Patent number: 5196983
    Abstract: A shutter, positioned between an electronic imaging device (such as a laser printer) and a film processor, is actuated by a solenoid which is driven by a driver network which isolates the solenoid coil when it is deactuated. If, after deactuation, a jam occurs, such that the shutter does not close completely, the jam is detected by a solenoid engagement sensing circuit. The sensing circuit includes a function generator, an operational amplifier having the solenoid coil connected between its input and output, an envelope detector and a comparator. The comparator produces a jam signal in response to an increase in the voltage detected by the presence of the solenoid plunger within the solenoid coil.
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: March 23, 1993
    Assignee: Eastman Kodak Company
    Inventor: Paul B. Stumpf
  • Patent number: 5182517
    Abstract: A method for detecting the motion and position state of a component of an inductive electric load. The component can be moved between two end positions by magnetic interaction, in which the total waveform of the drive current is divided into a plurality of states. By evaluating these individual states, comprehensive error diagnostics and a setting of operating parameters of the inductive electric load to operating conditions are possible.
    Type: Grant
    Filed: December 12, 1990
    Date of Patent: January 26, 1993
    Assignee: Daimler-Benz AG
    Inventors: Ulrich Thelen, Thomas Hirth
  • Patent number: RE34159
    Abstract: An electric motor controller comprises a circuit for selecting between driving and braking an electric motor in accordance with the health or otherwise of a pair of main electric motor control switches (14 and 16). In a preferred embodiment the health of the switch is determined by the voltage (A) between the switches. The controller also comprises apparatus for detecting the sense of movement of the motor. In the event that the motor is moving in a sense opposite to that selected, the apparatus increase field current to reduce the armature current thereby increasing the braking effect of the motor. Also in the controller are apparatus for changing from armature to field current control and vice versa, in response to a given magnitude of control signal. In order to provide an unambiguous change-over, a lockout circuit is provided to inhibit change-over in a transition region. The lockout circuit maintains the mode of control to above/beneath the change-over level when changing from one level to another.
    Type: Grant
    Filed: February 28, 1992
    Date of Patent: January 12, 1993
    Assignee: Chloride Group Public Limited Co.
    Inventors: Christopher A. Harrington, Dennis M. Jones