Patents by Inventor Robert T. Elms

Robert T. Elms has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20030231089
    Abstract: An improved test button assembly for use in a circuit breaker includes a frame and a button member, with the button member being pivotably mounted on the frame. A pair of microswitches are mounted on a printed circuit board that is disposed on the frame. The button member is alternately engageable with the two microswitches, with one of the microswitches being connectable with a ground fault protection circuit, and the other microswitch being connectable with an arc fault protection circuit. In an alternate embodiment, a common electrical contact is mounted on the button member, and a pair of contacts are mounted on the frame, with the common contact being alternately engageable with each of the contacts mounted on the frame. The contacts mounted on the frame are connected with the ground fault and arc fault protection circuits.
    Type: Application
    Filed: June 13, 2002
    Publication date: December 18, 2003
    Inventors: Robert T. Elms, Michael J. Whipple
  • Publication number: 20030223161
    Abstract: A trip signal generator for an arc fault or ground fault trip unit includes two inputs electrically interconnected with the two outputs of arc fault and ground fault detection circuits. A second input is electrically interconnected with an anode of a semiconductor switching device, such as a triac or SCR, which drives a trip coil of a trip solenoid. A circuit monitors the outputs of a power supply and provides an output when the outputs of the power supply are operational. A trip logic circuit drives a gate of the semiconductor switching device when the outputs of the power supply are operational, when one of the two first inputs is active, and when the second input is inactive.
    Type: Application
    Filed: June 3, 2002
    Publication date: December 4, 2003
    Inventors: Robert T. Elms, Theodore J. Miller
  • Publication number: 20030178982
    Abstract: A protective relay determines frequency of an AC signal of an electric power system. The protective relay includes a circuit measuring the AC signal period between zero crossings to provide a measured period value. A microprocessor includes a random access memory having a five-element array, which collects five consecutive values of the measured period values. A microprocessor routine chooses a median from the measured period values and generally determines the frequency based upon the median. The median is ignored and the previously determined line cycle period is adjusted to determine the new line cycle period if: an absolute value of a difference between a last value of the measured period values and a previously determined line cycle period is not less than a predetermined value; and the last value of the measured period values is within the limits of the array.
    Type: Application
    Filed: March 21, 2002
    Publication date: September 25, 2003
    Inventor: Robert T. Elms
  • Publication number: 20030169051
    Abstract: A testing device for detecting and locating an arcing fault in an electrical system includes a detector circuit for detecting one or more characteristics of the arcing fault proximate the arcing fault and outputting a responsive signal. An annunciator speaker or display annunciates the responsive signal when the detector circuit is proximate the arcing fault, in order to locate the arcing fault in the electrical system.
    Type: Application
    Filed: March 5, 2002
    Publication date: September 11, 2003
    Inventors: David M. Tallman, William J. Murphy, Robert T. Elms
  • Publication number: 20030169548
    Abstract: An annunciation system which will detect the majority of failed breakers and indicate to the consumer when a breaker needs to be replaced, but does not put the consumer in an emergency situation where critical loads have lost power. The annunication system provides a visible and audible indication of the failure of a breaker to trip either as a result of fault current conditions or a test of a ground fault or arc fault circuit.
    Type: Application
    Filed: March 8, 2002
    Publication date: September 11, 2003
    Inventors: Robert J. Clarey, Robert T. Elms
  • Publication number: 20030169545
    Abstract: A pulsing apparatus for an electrical system includes line and neutral terminals structured to input a nominal alternating current line voltage, a timing mechanism or circuit for generating a timing signal having a duty cycle from the line voltage; a transformer for transforming the line voltage to a stepped up voltage having the duty cycle; load and load neutral terminals; and an output circuit for outputting a current at about the stepped up voltage to the load and load neutral terminals. The stepped up voltage is greater than the line voltage and less than a rated voltage of the electrical system. The stepped up voltage is adapted to identify an arcing fault in the electrical system. The duty cycle limits an average value of the current to less than about 4 mA to about 6 mA.
    Type: Application
    Filed: March 5, 2002
    Publication date: September 11, 2003
    Inventors: David M. Tallman, Robert T. Elms
  • Patent number: 5982593
    Abstract: A miniature circuit breaker incorporating ground fault protection and arc fault protection includes a test mechanism including a ground fault test circuit for testing a ground fault detector trip mechanism, and an arc fault test circuit for testing an arc fault detector trip mechanism. A state machine circuit automatically controls the test mechanism to sequentially test both of the ground fault and arc fault detector trip mechanisms. A test push button is interconnected with the state machine circuit and, when pressed, initiates sequential testing of both of the ground fault and arc fault trip mechanisms.
    Type: Grant
    Filed: May 12, 1998
    Date of Patent: November 9, 1999
    Assignee: Eaton Corporation
    Inventors: Clive W. Kimblin, Robert T. Elms
  • Patent number: 5835321
    Abstract: Arcing-faults in an electric power distribution system are detected by a circuit which includes a band-pass filter generating a low frequency bandwidth limited arcing current signal having a bandwidth above the measurable harmonics of the ac current but below the frequency band of power line communications systems, about 3 KHz to 20 KHz and preferably about 6 KHz to 12 KHz. For each cycle of the ac current that this low frequency bandwidth limited arcing current exceeds a threshold, preferably related to the amplitude of the ac current, for a selected duration of the cycle, a fixed pulse is generated. If a time attenuated accumulation of these fixed pulses reaches a selected level representative of a number of closely spaced cycles in which the arcing current has been detected for the selected duration, an arc indicative signal is output.
    Type: Grant
    Filed: August 2, 1996
    Date of Patent: November 10, 1998
    Assignee: Eaton Corporation
    Inventors: Robert T. Elms, John C. Schlotterer
  • Patent number: 5754440
    Abstract: A monitor for an ac electrical system generates on-line a display presenting the values, either in magnitude or as a percent of the fundamental, of 50 harmonics of any of the currents and voltages in the system. The display also incudes the phase angle of each harmonic relative to a reference waveform, which is preferably phase A-B voltage or phase A to neutral voltage.
    Type: Grant
    Filed: February 28, 1996
    Date of Patent: May 19, 1998
    Assignee: Eaton Corporation
    Inventors: Roger W. Cox, Robert T. Elms
  • Patent number: 5751234
    Abstract: A hybrid monolithic IC that is standardized for controlling various types of electrical equipment, such as circuit breakers, motor controllers and the like. The IC is a hybrid monolithic IC, fabricated in CMOS technology. The shortcomings of utilizing CMOS technology for linear or analog circuitry is overcome by the implementation of the IC to provide a hybrid monolithic IC that is relatively less expensive than using multiple IC's or a single IC fabricated from biCMOS technology. Also, by utilizing a single IC, such control and monitoring circuitry can be located in existing electrical equipment. The IC includes an on-board microprocessor, an A/D subsystem and various input/output devices which make it adaptable for use in various types of electrical equipment.
    Type: Grant
    Filed: September 23, 1996
    Date of Patent: May 12, 1998
    Assignee: Eaton Corporation
    Inventors: John C. Schlotterer, Robert T. Elms
  • Patent number: 5706214
    Abstract: For calibration of a microprocessor-based electrical metering device, the scaled values of current and voltage inputs are presented on a display along side of the associated scaling factors. Soft keys on the display are used to increment or decrement the scaling factors to adjust the scaled values of the associated current or voltage to the value indicated by a precision reference meter which measures test values of current and voltage provided by a stable source. For analog inputs, both a zero scaling factor (offset) and a full scale factor (slope) are presented on the display adjacent the scaled analog value and can be separately adjusted by the soft keys.
    Type: Grant
    Filed: March 29, 1995
    Date of Patent: January 6, 1998
    Assignee: Eaton Corporation
    Inventors: Sally A. Putt, Robert T. Elms
  • Patent number: 5706204
    Abstract: A monitor/analyzer for an ac electrical system can be programmed through a display on the front panel to respond to selected events by generating triggers signals when selected monitored electrical parameters including neutral current exceed programmed thresholds. The trigger signals initiate simultaneous waveform capture of multiple waveforms in the ac system. Multiple trigger signals result in sequential waveform capture so that if a plurality of triggers are programmed for the same event, extended waveform data is captured for the event. Alarm screens are generated in response to the events, as well as for hardware failure, an excessive neutral-to-ground voltage or reverse sequence.
    Type: Grant
    Filed: February 28, 1996
    Date of Patent: January 6, 1998
    Assignee: Eaton Corporation
    Inventors: Roger W. Cox, Robert T. Elms, Sally A. Putt
  • Patent number: 5661643
    Abstract: A power supply for converting a plurality of alternating current (AC) and direct current (DC) input line voltages to a DC output voltage includes a converter for converting the input voltages to an intermediate voltage at a first node; a switching regulator having a power voltage at a second node for providing a reference voltage therefrom, and for providing a switching signal at a third node from the reference voltage and a feedback voltage; a circuit for electrically interconnecting the first node to the second node whenever the intermediate voltage exceeds a predetermined voltage; a transformer including a primary winding electrically interconnected with the first node, and a secondary winding having a secondary voltage; a feedback circuit cooperating with the transformer for providing the feedback voltage therefrom; a switching circuit responsive to the switching signal at the third node for switching an electrical current from the first node through the primary winding; and a circuit electrically interco
    Type: Grant
    Filed: February 20, 1996
    Date of Patent: August 26, 1997
    Assignee: Eaton Corporation
    Inventors: John H. Blakely, Robert T. Elms
  • Patent number: 5606249
    Abstract: Electric apparatus responsive to currents and/or voltages having wide dynamic ranges incorporates ranging circuits for each input in which a multiplexer providing the ranging selection has a common input connected to the output of an operational amplifier providing the selective gain and has a plurality of outputs connecting selected ones of a plurality of series connected precision resistors in a feedback loop around the operational amplifier. A second operational amplifier is connected as a follower to the last output of the multiplexer so that the gain applied to the output signal is not distorted by the resistance of the switches in the multiplexer. For three-phase systems not having a neutral conductor, phase to neutral voltages with ranging are generated by subtracting a neutral-to-ground voltage produced from an artificial ground created by connecting three resistors in a wye across the phase conductors from the phase-to-ground voltages applied to the ranging circuit input.
    Type: Grant
    Filed: January 27, 1995
    Date of Patent: February 25, 1997
    Assignee: Eaton Corporation
    Inventor: Robert T. Elms
  • Patent number: 5587917
    Abstract: A digital monitor/analyzer for an ac electrical power system samples the current and voltage waveforms at a slow rate for performing metering functions, and at a high rate for analyzing harmonic content. Sampling is performed in sampling frames comprising a plurality of repetitions of sampling for a selected number of cycles followed by a delay of a fraction of a cycle. This effects equivalent sampling at a higher rate for slow speed sampling over a frame. High speed sampling is performed over only one repetition of the selected number of cycles in a frame so that it can be carried out sychronously as required for the harmonic analysis. The high speed sampling rate is an integer multiple of the slow speed rate so that slow speed data can be extracted from the high speed samples for continuous metering. Fourier analysis of the harmonic content of the waveforms is performed on the odd interrupts while all of the other tasks are apportioned out over the even interrupts of a sampling frame.
    Type: Grant
    Filed: October 17, 1994
    Date of Patent: December 24, 1996
    Assignee: Eaton Corporation
    Inventor: Robert T. Elms
  • Patent number: 5525985
    Abstract: A hybrid monolithic IC that is standardized for controlling various types of electrical equipment, such as circuit breakers, motor controllers and the like. The IC is a hybrid monolithic IC, fabricated in CMOS technology. The shortcomings of utilizing CMOS technology for linear or analog circuitry is overcome by the implementation of the IC to provide a hybrid monolithic IC that is relatively less expensive than using multiple IC's or a single IC fabricated from biCMOS technology. Also, by utilizing a single IC, such control and monitoring circuitry can be located in existing electrical equipment. The IC includes an on-board microprocessor, an A/D subsystem and various input/output devices which make it adaptable for use in various types of electrical equipment.
    Type: Grant
    Filed: December 28, 1990
    Date of Patent: June 11, 1996
    Assignee: Eaton Corporation
    Inventors: John C. Schlotterer, Robert T. Elms
  • Patent number: 5493468
    Abstract: In a multiple contactor installation where each contactor provides overcurrent protection, overload information in passed from one active contactor to the next as a percentage of the trip level of the respective contactors.
    Type: Grant
    Filed: September 30, 1993
    Date of Patent: February 20, 1996
    Assignee: Eaton Corporation
    Inventors: Patrick J. Hunter, Robert T. Elms, Gary F. Saletta, Denis A. Mueller
  • Patent number: 5487016
    Abstract: A microprocessor based device for generating a representation of the total harmonic distortion in an ac waveform derives from digital samples of the waveform a fundamental signal representing the value of the fundamental frequency component of each sample. A harmonic signal is then generated as the difference between the sample value and the fundamental component of the sample. An output signal representing total harmonic distortion is then generated as the ratio of the RMS value of the harmonic signal to the RMS value of the fundamental signal converted to a percentage.
    Type: Grant
    Filed: November 4, 1994
    Date of Patent: January 23, 1996
    Assignee: Eaton Corporation
    Inventor: Robert T. Elms
  • Patent number: 5406071
    Abstract: A process variable such as the load current supplied through an electrical contactor is encoded as a 4 to 20 mA current signal via an optically coupled pulse width modulated output circuit. A microprocessor produces the pulse width modulated signal at a duty cycle varying with the load current. The LED of an opto-coupler transfers the signal to a phototransistor, and a voltage regulator and switching circuit drive the phototransistor so as to minimize switching times. The voltage regulator maintains a DC voltage at the collector of the phototransistor, which is operated at a constant emitter current. The LED supplies base current to the phototransistor when the pulse width modulated signal is high. An amplifier is coupled to the emitter of the phototransistor, and the output of the amplifier is coupled back to the base of the phototransistor via a Schottky diode pair. The amplifier output varies with whether or not the base current needed to maintain constant emitter current is obtained from the LED.
    Type: Grant
    Filed: July 20, 1993
    Date of Patent: April 11, 1995
    Assignee: Eaton Corporation
    Inventor: Robert T. Elms
  • Patent number: 5394018
    Abstract: False ac signals produced by a noise suppression capacitor across a switch applying a switched ac line voltage signal to a logic input of a microprocessor in an electrical apparatus such as, for example, a contactor or circuit breaker, are phase shifted with respect to a true ac input by inserting two series resistors, and a diode shunting one resistor, between the switch and the logic input. This creates a larger window in which to discriminate between the zero crossings of the true and false ac signals.
    Type: Grant
    Filed: December 31, 1992
    Date of Patent: February 28, 1995
    Assignee: Eaton Corporation
    Inventor: Robert T. Elms