Patents by Inventor Slobodan Krstic

Slobodan Krstic 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: 20050021301
    Abstract: The present invention is directed to a system and method for proactively determining motor wellness arising from potential mechanical faults of the motor. A controller is configured to detect indicia of impending mechanical motor faults. The controller includes a processor configured to determine motor parameters of a given motor including a load and generate a set of baseline data for the given motor. The processor is also configured to acquire current spectrum data from the given motor during operation, map at least one from a plurality of load bins based on the load, and generate a mechanical fault signature from the current spectrum. The processor is caused to compare the mechanical fault signature to baseline data from the set of baseline data corresponding to the mapped bin and determine amplitude variances within the mechanical fault signature indicative of an impending mechanical fault prior to an actual mechanical fault occurrence.
    Type: Application
    Filed: June 2, 2004
    Publication date: January 27, 2005
    Inventors: Steven Dimino, Thomas Habetler, Ramzy Obaid, Slobodan Krstic, Michael Nowak, Yanzhen Liu
  • Publication number: 20050007096
    Abstract: The present invention is directed to a power meter or overload relay including a housing and a plurality of sensors configured to monitor operation of a motor. A processor disposed within the housing and configured to receive operational feedback from the plurality of sensor and proactively determine an operational wellness of the motor from the operational feedback.
    Type: Application
    Filed: June 2, 2004
    Publication date: January 13, 2005
    Inventors: Steven Dimino, Thomas Habetler, Ramzy Obaid, Slobodan Krstic, Michael Nowak, Yanzhen Liu
  • Patent number: 6590757
    Abstract: Electrical equipment (14) is safeguarded from damage due to parallel arc faults by a circuit that provides several levels of protection. A semiconductor switch (18) and a current sensor (24) are placed in series with the electrical equipment (14). When the current to the equipment exceeds a first threshold for a predefined period of time, the semiconductor switch (18) is rendered non-conductive until the circuit is specifically reset. When the current to the equipment exceeds a greater second threshold, a pulsed signal alternately places the semiconductor switch (18) in conductive and non-conductive states so that the average current applied to the equipment (14) is within an acceptable level. The pulses are measured to determine whether a parallel arc fault has occurred. When the measured pulses (74) are within a predetermined range, a parallel arc fault is declared and the semiconductor switch (18) is rendered non-conductive.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: July 8, 2003
    Assignee: Eaton Corporation
    Inventors: Birger Pahl, Ronald R. Jahn, William E. Berkopec, Slobodan Krstic, Joseph C. Zuercher, Jerome K. Hastings
  • Publication number: 20030063420
    Abstract: Electrical equipment (14) is safeguarded from damage due to parallel arc faults by a circuit that provides several levels of protection. A semiconductor switch (18) and a current sensor (24) are placed in series with the electrical equipment (14). When the current to the equipment exceeds a first threshold for a predefined period of time, the semiconductor switch (18) is rendered non-conductive until the circuit is specifically reset. When the current to the equipment exceeds a greater second threshold, a pulsed signal alternately places the semiconductor switch (18) in conductive and non-conductive states so that the average current applied to the equipment (14) is within an acceptable level. The pulses are measured to determine whether a parallel arc fault has occurred. When the measured pulses (74) are within a predetermined range, a parallel arc fault is declared and the semiconductor switch (18) is rendered non-conductive.
    Type: Application
    Filed: September 28, 2001
    Publication date: April 3, 2003
    Applicant: Eaton Corporation
    Inventors: Birger Pahl, Ronald R. Jahn, William E. Berkopec, Slobodan Krstic, Joseph C. Zuercher, Jerome K. Hastings
  • Patent number: 5866864
    Abstract: An electric arc extinguishing mechanism is provided for an electric current switching apparatus of the type having a pair of contacts which selectively engage to complete an electric circuit. The mechanism includes a plurality of splitter plates located adjacent to the contacts and formed of electrically conductive material. Each splitter plate has a body of electrically conductive material, and a casing with a pair of planar portions on opposite sides of the body and connected by the curved edge portion. The edge portion is adjacent the contacts with the planar portions extending from the edge portion in an open loop having a gap. Any arc introduced between adjacent splitter plates moves around the open loop before being extinguished thereby not residing in one spot long enough to cause gross melting and associated erosion of the splitter plate.
    Type: Grant
    Filed: July 14, 1997
    Date of Patent: February 2, 1999
    Assignee: Eaton Corporation
    Inventors: Hemant K. Mody, James C. Vander Meer, Slobodan Krstic, Peter K. Moldovan
  • Patent number: 5490031
    Abstract: Solenoid control circuitry can be used with either a first solenoid requiring a relatively large holding current or a second solenoid requiring a relatively small holding current. A solenoid connected with the solenoid control circuitry is initially energized to effect operation of the solenoid from an unactuated condition to an actuated condition. A detector detects whether a characteristic of the initial energization of the solenoid corresponds to a characteristic of the first solenoid or the second solenoid. The solenoid control circuitry varies the amount of holding current supplied to the solenoid as a function of whether the detector detects the first solenoid requiring the relatively large holding current or the second solenoid requiring a relatively small holding current. A fault detection circuit is provided to interrupt energization of the solenoid in the event of an excessive flow of current.
    Type: Grant
    Filed: December 20, 1994
    Date of Patent: February 6, 1996
    Assignee: Eaton Corporation
    Inventors: Scott W. Braun, Fred W. Haselow, Slobodan Krstic
  • Patent number: 4642481
    Abstract: A hybrid switch (2) having a solid state circuit (2a) including a thyristor (SCR) for closing and reopening a supply circuit (S,4,6) to a load (L) and contacts including an isolating contact (S1) for connecting power to and disconnecting power from the solid state circuit (2a), a control contact (S2) for initiating turn-on and turn-off of the thyristor (SCR), and a bypass contact (S3) for shunting the solid state circuit (2a) after the load has been energized. A zero voltage crossover circuit (ZVC) allows turn-on of the thyristor (SCR) only when the A.C. supply voltage is below a preset value to avoid arcing at the contacts on closing. The inherent zero current crossing turn-off characteristic of the thyristor (SCR) avoids arcing at the contacts on opening.
    Type: Grant
    Filed: August 8, 1985
    Date of Patent: February 10, 1987
    Assignee: Eaton Corporation
    Inventors: Ralph F. Bielinski, James R. Jaeschke, Slobodan Krstic, Earl T. Piber, Peter J. Theisen
  • Patent number: 4420784
    Abstract: A hybrid D.C. power controller of the relay/circuit breaker type that uses a hybrid arrangement of hard contacts (4) and power FET's (18, 20) in cooperative functional combination as the arc quenching means for 270 volt D.C. power systems in low atmospheric pressure environments such as at 80,000 feet altitude in aircraft applications. Also, the relay is provided with arc horns (44c, 48b, 48c, 46c), magnetic field amplifiers (60, 62) looped stationary contacts (44, 46), arc splitters (64, 66), and gas ablating insulating members (60b, 62b, 72, 74, 64b, 66) to enable the relay to interrupt the power circuit if necessary without the help of the power FET's. The power FET's are controlled in both opening and closing the power circuit to afford arcless contact operation in normal load make-break situations. Current and voltage sensing (28, 32) and sampling (CS, VS) circuits determine when to turn the power FET's on after contact arcing has provided the required values.
    Type: Grant
    Filed: December 4, 1981
    Date of Patent: December 13, 1983
    Assignee: Eaton Corporation
    Inventors: C. Gregory Chen, Ping S. Lee, Peter J. Theisen, Slobodan Krstic