Patents Represented by Attorney Philip A. Florenzo
  • Patent number: 5764626
    Abstract: A test instrument for monitoring operation of ATM communication networks is capable of identifying individual cells passing through a node to which the instrument is connected as belonging to a particular virtual connection, and transmitting test cells replacing the identified cells, transmitting modified identified cells, or augmenting cells transmitted over the identified virtual connection with operations, administration, and maintenance cells. Specific test cells can be detected by a second test instrument connected to a node elsewhere in the network for accurately monitoring specific network operating characteristics. Cell delay, cell delay variation, cell error rates, and the like may all be monitored by the test instrument according to the invention.
    Type: Grant
    Filed: November 17, 1995
    Date of Patent: June 9, 1998
    Assignee: Telecommunications Techniques Corporation
    Inventor: Cole S. VanDervort
  • Patent number: 5761191
    Abstract: An instrument for identifying the types of individual cells in a stream of ATM cells by individually examining the cell header and cell payload information of each cell. A microprogram within a microsequencer is vectored responsive to each cell type for updating appropriate statistical counters. Identification of individual cell types by examination of their cell headers on networks operating at speeds of up to 622 Mbps allows numerous network utilization statistics of interest to be gathered.
    Type: Grant
    Filed: November 28, 1995
    Date of Patent: June 2, 1998
    Assignee: Telecommunications Techniques Corporation
    Inventors: Cole S. VanDervort, Elias E. Fahel
  • Patent number: 5699346
    Abstract: A test instrument for measuring the rate and size of bursts of cells received at a given node of an ATM network with respect to a particular virtual connection includes a cell filter for identifying cells belonging to the virtual connection. The "leaky bucket" algorithm is implemented for determining conformity with contractual performance standards, and for delineating the bursts.
    Type: Grant
    Filed: November 17, 1995
    Date of Patent: December 16, 1997
    Assignee: Telecommunications Techniques Corporation
    Inventor: Cole S. VanDervort
  • Patent number: 5627758
    Abstract: A vector control board for an electric vehicle propulsion system motor controller comprising a microcontroller for generating torque requests, a digital signal processor for receiving the torque requests from the microcontroller and for generating phase voltage signals in accordance with the torque requests, and a digital gate array for receiving the phase voltage signals from the digital signal processor and for generating gate drive signals from the phase voltage signals.
    Type: Grant
    Filed: June 10, 1994
    Date of Patent: May 6, 1997
    Assignee: Northrop Grumman Corporation
    Inventors: Geoffrey B. Lansberry, James L. Munro
  • Patent number: 5623724
    Abstract: A ceramic capacitor suitable for high energy density and high temperature application is disclosed. Such a capacitor is prepared by producing the selected ceramic powder via the sol-gel process forming the capacitor to the desired shape with the resulting powder using tape casting technology and firing the "green" form so produced.
    Type: Grant
    Filed: August 9, 1994
    Date of Patent: April 22, 1997
    Assignee: Northrop Grumman Corporation
    Inventors: Stephen R. Gurkovich, Kenneth C. Radford, Deborah P. Partlow
  • Patent number: 5611955
    Abstract: A substrate for use in semiconductor devices, fabricated of silicon carbide and having a resistivity of greater than 1500 Ohm-cm. The substrate being characterized as having deep level impurities incorporated therein, wherein the deep level elemental impurity comprises one of a selected heavy metal, hydrogen, chlorine and fluorine. The selected heavy metal being a metal found in periodic groups IIIB, IVB, VB, VIB, VIIB, VIIIB, IB and IIB.
    Type: Grant
    Filed: October 18, 1993
    Date of Patent: March 18, 1997
    Assignee: Northrop Grumman Corp.
    Inventors: Donovan L. Barrett, Hudson M. Hobgood, James P. McHugh, Richard H. Hopkins
  • Patent number: 5612580
    Abstract: An uninterruptible power supply for providing continuous power from a power source line to a load is provided. In particular, the uninterruptible power supply may either operate in an "Off-Line" mode or one of two "On-Line" modes. The uninterruptible power supply operates in the "Off-Line" mode when the power source line voltage is above a first threshold value. The uninterruptible power supply routes power from the power source line to the load in the "Off-Line" mode. The uninterruptible power supply operates in a first "On-Line" mode when the power source line voltage drops below a first threshold value but exceeds a second threshold voltage, or the frequency of the power source line exceeds a predetermined range. The uninterruptible power supply boosts the power source line voltage in the first "On-Line" mode of operation and applies the boosted signal to the load.
    Type: Grant
    Filed: October 10, 1995
    Date of Patent: March 18, 1997
    Assignee: Northrop Grumman Corporation
    Inventors: Vytautas F. Janonis, Roland K. Massatti, Regis E. Novitskey
  • Patent number: 5612547
    Abstract: A static induction transistor fabricated of silicon carbide, preferably 6H polytype, although any silicon carbide polytype may be used. The preferred static induction transistor is the recessed Schottky barrier gate type. Thus, a silicon carbide substrate is provided. Then, a silicon carbide drift layer is provided upon the substrate, wherein the drift layer has two spaced-apart protrusions or fingers which extend away from the substrate. Each protrusion of the drift layer has a source region of silicon carbide provided thereon. A gate material is then provided along the drift layer between the two protrusions. A conductive gate contact is provided upon the gate material and a conductive source contact is provided upon each source region. A conductive drain contact is provided along the substrate. Other gate types for the static induction transistor are contemplated. For example, a planar Schottky barrier gate may be employed.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: March 18, 1997
    Assignee: Northrop Grumman Corporation
    Inventors: Rowland C. Clarke, Richard R. Siergiej, Saptharishi Sriram
  • Patent number: 5607520
    Abstract: A method and apparatus for performing continuous reel-to-reel passivation of a stainless steel wire usable in an underwater electromechanical or optical cable of a mine hunting sonar or similar marine system, which supplies the stainless steel wire, under tension, immerses a first portion of the stainless steel wire in 10-20% nitric acid bath at ambient temperature; applies a current from a DC power supply to the immersed first portion of the stainless steel wire, advances the stainless steel wire, under tension, to repeat the immersing and current supplying on a second portion of the stainless steel wire, washes the first portion of the stainless steel wire in a flowing water wash, dries the first portion of the stainless steel wire with forced air, advances the stainless steel wire, under tension, to repeat the washing and drying on the second portion of the stainless steel wire, and stores the stainless steel wire under tension.
    Type: Grant
    Filed: August 18, 1995
    Date of Patent: March 4, 1997
    Assignee: Northrop Grumman Corporation
    Inventor: David G. Tipton
  • Patent number: 5608360
    Abstract: Multiple resonator stages are connected in series to form a closed loop. Each of these cascaded resonator stages includes at least a high frequency resonator and an amplifier. The amplifier amplifies the output of the high frequency resonator. Each stage also includes a power divider connected to the amplifier output. The power divider has at least two outputs. One of the two power divider outputs serves as an output of the oscillator formed by the cascaded resonator stages. The other output of the power divider is connected to the input of the next high frequency resonator stage. The oscillator further includes a phase shifter connected between two of the high frequency resonator stages to achieve a closed loop phase shift of N(360) degrees at the oscillator operating frequency, where N is an integer. The high frequency resonators may be acoustic resonators such as surface acoustic wave resonators (SAWR).
    Type: Grant
    Filed: November 3, 1995
    Date of Patent: March 4, 1997
    Assignee: Northrop Grumman Corporation
    Inventor: Michael M. Driscoll
  • Patent number: 5606576
    Abstract: An adaptive mode control system is provided which includes a transmitter including apparatus for inputting format information regarding the waveform structure of an AM compatible digital broadcast signal. The transmitter also includes apparatus for inputting user data such as the information to be broadcast. The transmitter selects the waveform parameters in response to the format information and produces control channel information. The transmitter uses this control channel information in combination with the user data to produce composite data. The transmitter generates an over-the-air signal waveform using the composite data and waveform parameters. Each receiver includes apparatus for detecting the over-the-air signal waveform and composite data generated by the transmitter. The receiver further includes apparatus for parsing the composite data into user data and control channel information.
    Type: Grant
    Filed: January 23, 1995
    Date of Patent: February 25, 1997
    Assignee: Northrop Grumman Corporation
    Inventors: Mark J. Dapper, Michael J. Geile, Barry W. Carlin
  • Patent number: 5606413
    Abstract: To dramatically reduce image data processing requirements in spectroscopic imaging systems, an optical filter is alternatingly tuned to a pair of selected passband wavelengths related to an absorption wavelength of a sample under test, such that only light of the two selected wavelengths received from the test sample are recorded as alternating image frames by a CCD optical detector. Successive pairs of consecutive image frames are computer processed, on a corresponding pixel-by-pixel basis, to generate a series of composite image frames that may be displayed in enhanced contrast to permit real time analysis of a sample characteristic of interest.
    Type: Grant
    Filed: January 19, 1995
    Date of Patent: February 25, 1997
    Assignee: Northrop Grumman Corporation
    Inventors: Peter A. Bellus, Terry L. McKinney
  • Patent number: 5606291
    Abstract: A digital controller time multiplexes dithering of the microwave frequency control signal and a laser wavelength control signal in a miniaturized cesium vapor atomic frequency standard. A unique common charge/sample and dump integrator amplifies the photodetector output for the + and - dither of both the laser current and microwave frequency. To suppress error in the integrated photodetector output attributable to noise generated by the digital processor, the processor is placed in a sleep mode during the integration intervals. To further suppress errors, the cesium vapor electric heaters are not energized during the intervals when the microwave signal is being dithered.
    Type: Grant
    Filed: November 6, 1995
    Date of Patent: February 25, 1997
    Assignee: Northrop Grumman Corporation
    Inventor: William R. Verbanets
  • Patent number: 5594636
    Abstract: A method and apparatus for AC-to-AC power conversion wherein commutation from one switch in a switching group to a second switch is effected while both switches are enabled simultaneously without causing a short circuit between the phase input lines associated with each respective switch. Each switch in a switching group is bidirectional and polarity-controlled, and may be selectively enabled to conduct only negative-polarity or positive-polarity current, or may be disabled. An overvoltage clamping circuit is also provided with each switch. A switch gating control circuit is employed to provide selective operation of the switches in a particular switch group.
    Type: Grant
    Filed: June 29, 1994
    Date of Patent: January 14, 1997
    Assignee: Northrop Grumman Corporation
    Inventor: Colin D. Schauder
  • Patent number: 5581171
    Abstract: An on-board electric vehicle battery charger includes a surge limiter circuit, a power factor control circuit, and a resonant inverter circuit. The power factor control circuit includes a boost regulator circuit providing a fixed voltage on an output capacitor. The resonant inverter circuit uses a resonance capacitor and the leakage inductance of an output transformer to establish a resonance frequency at least 500 times the AC input power frequency.
    Type: Grant
    Filed: June 10, 1994
    Date of Patent: December 3, 1996
    Assignee: Northrop Grumman Corporation
    Inventors: Charles S. Kerfoot, Patricia A. O'Donnell, David L. Schantz, Jr.
  • Patent number: 5569966
    Abstract: A power bridge for an electric vehicle propulsion system, comprising a switching circuit including first and second switching elements operable between "on" and "off" states and a midpoint detector coupled to the switching circuit for detecting a failure of at least one of the first and second switching elements, where the midpoint detector is capable of detecting and isolating a failure when the switching elements are in the "on" or the "off" states.
    Type: Grant
    Filed: June 10, 1994
    Date of Patent: October 29, 1996
    Assignee: Northrop Grumman Corporation
    Inventors: David L. Schantz, Jr., Brian A. DeAbreu
  • Patent number: 5570324
    Abstract: A control system connected to a passive underwater transducer array is located remotely from the array, e.g. above the surface of the water, to localize an underwater source of acoustic energy in a relatively simple manner by introducing listener-motion, such as head turning or body motion of a listener, into the sound localization process and does so without any underwater mechanical linkage of any kind. This is achieved by a pair of listener-motion coupled potentiometers, referred to as mixing-pots, located at the site of the listener, being connected to the outputs of an array of passive acoustic transducers, with the two outputs of the mixing-pots being coupled to a pair of headphones worn by the listener.
    Type: Grant
    Filed: September 6, 1995
    Date of Patent: October 29, 1996
    Assignee: Northrop Grumman Corporation
    Inventor: Frederick G. Geil
  • Patent number: 5567991
    Abstract: An electric vehicle relay assembly including a main relay and a flexible circuit electrically connected to the main relay. The relay assembly further includes a connection for mounting the flexible circuit onto the main relay and a wiring board affixed to the flexible circuit. The flexible circuit compensates for mechanical tolerance errors within the connection. The wiring board includes relay circuitry electrically connected to the flexible circuit.
    Type: Grant
    Filed: June 10, 1994
    Date of Patent: October 22, 1996
    Assignee: Northrop Grumman Corporation
    Inventors: David L. Schantz, James H. DeOms, Ronnie L. Starling, Michael J. Ankrom
  • Patent number: 5517063
    Abstract: A power bridge assembly for providing electric current to stator windings of an electric motor used in an electric propulsion system for an electric vehicle. The power bridge is assembled on a laminated bus bar. An upper plate of the bus bar connects to one side of a high voltage battery, a lower plate of the bus bar connects to the other side of the high voltage battery, and an insulation layer is sandwiched between the upper and lower plates. Electrical switches and capacitors sandwich the laminated bus bar. With this structure, two fasteners, one for positive voltage and one for negative voltage, can connect the bus bar, capacitors, and switches both electrically and mechanically. The sandwich structure eliminates parasitic inductance from the electrical connections.
    Type: Grant
    Filed: June 10, 1994
    Date of Patent: May 14, 1996
    Assignee: Westinghouse Electric Corp.
    Inventors: David L. Schantz, Jr., James H. Deoms, Brian H. Smith
  • Patent number: 5492867
    Abstract: A method for forming a solid state mass spectrograph for analyzing a sample gas is provided in which a plurality of cavities are formed in a substrate, preferably, a semiconductor. Each of these cavities forms a chamber into which a different component of the mass spectrograph is provided. A plurality of orifices are formed between each of the cavities, forming an interconnecting passageway between each of the chambers. A dielectric layer is provided inside the cavities to serve as a separator between the substrate and electrodes to be later deposited in the cavity. An ionizer is provided in one of the cavities and an ion detector is provided in another of the cavities. The formed substrate is provided in a circuit board which contains interfacing and controlling electronics for the mass spectrograph. Preferably, the substrate is formed in two halves and the chambers are formed in a corresponding arrangement in each of the substrate halves.
    Type: Grant
    Filed: October 7, 1994
    Date of Patent: February 20, 1996
    Assignee: Westinghouse Elect. Corp.
    Inventors: Joseph C. Kotvas, Timothy T. Braggins, Robert M. Young, Carl B. Freidhoff