Patents by Inventor Philip R. Cooke

Philip R. Cooke 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).

  • Patent number: 6366070
    Abstract: A switching voltage regulator employs a “dual modulation” scheme to control the regulator's switching components. A control circuit indirectly monitors load current. When the load decreases, the control circuit reduces both the duty ratio and the frequency of the control signals which operate the switching transistors, thereby maintaining a high efficiency level over a wider output current range than can be achieved with fixed-frequency control signals. In a preferred embodiment, the regulator employs three operating modes. For heavy loads, the switching components are operated at a constant frequency. For moderate-to-light loads, the dual modulation control scheme is used. For light loads, the regulator enters a “pulse-skipping” mode which can achieve very low operating frequencies to further improve efficiency.
    Type: Grant
    Filed: July 12, 2001
    Date of Patent: April 2, 2002
    Assignee: Analog Devices, Inc.
    Inventors: Philip R. Cooke, Richard Redl
  • Patent number: 5710697
    Abstract: A power supply controller implementing frequency foldback and volt-second duty cycle clamp features. An oscillator timing capacitor is charged with a fixed current and is discharged with a fixed current when the output voltage is above a predetermined level and with a decreasing current when the output voltage falls below the predetermined level, so as to decrease the power supply operating frequency during short circuit or overload fault conditions. A volt-second duty cycle clamp circuit limits the duty cycle to a maximum value which is independent of the tolerance of a capacitor which sets the maximum duty cycle as a function of the power supply input voltage.
    Type: Grant
    Filed: March 26, 1996
    Date of Patent: January 20, 1998
    Assignee: Unitrode Corporation
    Inventors: Philip R. Cooke, John R. Wiggenhorn
  • Patent number: 5528444
    Abstract: A shorted diode protection system for a traction vehicle propulsion system including a synchronous generator having armature and field windings and a bridge rectifier circuit coupling the generator armature windings to a traction motor employs a normally non-conducting solid-state controllable electric valve in parallel with the generator field windings. When a rectifier diode of the bridge rectifier circuit fails short, an a-c current is reflected into the generator field winding circuit. Upon detection of this reflected current, the valve is switched into a conducting state, thereby limiting the voltage on the generator field windings.
    Type: Grant
    Filed: September 23, 1994
    Date of Patent: June 18, 1996
    Assignee: General Electric Company
    Inventors: Philip R. Cooke, Joseph A. Laukaitis
  • Patent number: 5528445
    Abstract: A fault current protection system for a traction vehicle propulsion system including a synchronous generator having armature and field windings and power conditioning circuitry connecting the generator armature windings to a traction motor employs a normally charged capacitor which, in response to a fault signal resulting from excess current in the generator armature windings, is electrically switched into parallel with the excitation current source connected to the generator field windings so as to discharge through the generator field windings and commutate the excitation current source.
    Type: Grant
    Filed: September 23, 1994
    Date of Patent: June 18, 1996
    Assignee: General Electric Company
    Inventors: Philip R. Cooke, Joseph A. Laukaitis
  • Patent number: 5483436
    Abstract: A power supply for a gate drive voltage supply system for a power inverter is coupled to receive a variable DC voltage and operable to produce a regulated DC output voltage to each of a plurality of distributed electronic switching devices. The system includes a plurality of linear voltage regulators with each respective one of the regulators having a power input terminal coupled to a common DC link. Each of the regulators is separately connected to a ground reference at a ground reference power terminal of a corresponding one of the switching devices so as to eliminate ground loops and voltage drops over a common ground bus.
    Type: Grant
    Filed: August 30, 1993
    Date of Patent: January 9, 1996
    Assignee: General Electric Company
    Inventors: Herbert J. Brown, Philip R. Cooke, Donald D. Bock
  • Patent number: 5229700
    Abstract: A method and system for calibration of a primary signal processing path without interruption of signal processing utilizes a calibration signal processing path which is periodically used to process a signal concurrently with processing in the primary path. Any difference is compensated by gain adjustment in the primary path. In one form, a plurality of primary paths are sequentially compared with a calibrated path. The calibrated path is periodically checked using a precision reference and any error is corrected before comparison of the primary paths.
    Type: Grant
    Filed: April 24, 1992
    Date of Patent: July 20, 1993
    Assignee: General Electric Company
    Inventors: Thomas D. Stitt, Philip R. Cooke, Ajith K. Kumar