Patents by Inventor David Murfett

David Murfett 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: 8891267
    Abstract: A circuit arrangement with standby mode minimizing power and/or current consumption having a mains AC power supply terminals and an active circuit capable of converting said mains AC power to lower voltage DC levels for operating in an active mode or in a standby mode as required by an appliance such that the selection of the current sensing resistor value for said current sensing resistor limits the maximum peak current through the FET so that the current sensing resistor arrangement is capable of providing significant increases in a steeper rise time of the current at around mains AC power supply zero crossing, so that current is pulled high while the mains AC power supply voltage is low.
    Type: Grant
    Filed: August 31, 2011
    Date of Patent: November 18, 2014
    Assignee: Hendon Semiconductors Pty. Ltd.
    Inventors: Paul Bourne, Philip Tracy, David Murfett
  • Publication number: 20130286528
    Abstract: An electrical relay contact arrangement for switching an electrical relay ‘on’ or ‘off’ at zero crossings of an AC mains supply, wherein the arrangement rather than immediately sending a control signal from a microprocessor to the input of the electrical relay to close or open the mechanical electrode contacts when switching is required, relies upon a time interval made up two delays, firstly when the microprocessor first recognizes switching is required there is a waiting period until the next zero crossing, and then a further delay which is the time difference between the lag times of the mechanical contact electrodes physically opening or closing and that of the next zero crossing.
    Type: Application
    Filed: April 19, 2013
    Publication date: October 31, 2013
    Inventors: David Murfett, Stephen Francis
  • Publication number: 20130201735
    Abstract: A circuit arrangement with standby mode minimising power and/or current consumption having a mains AC power supply terminals and an active circuit capable of converting said mains AC power to lower voltage DC levels for operating in an active mode or in a standby mode as required by an appliance such that the selection of the current sensing resistor value for said current sensing resistor limits the maximum peak current through the FET so that the current sensing resistor arrangement is capable of providing significant increases in a steeper rise time of the current at around mains AC power supply zero crossing, so that current is pulled high while the mains AC power supply voltage is low.
    Type: Application
    Filed: August 31, 2011
    Publication date: August 8, 2013
    Applicant: HENDON SEMICONDUCTORS PTY LTD
    Inventors: Paul Bourne, Philip Tracy, David Murfett
  • Patent number: 7840734
    Abstract: A bus buffer can include a data buffer and a clock signal buffer. The data buffer for can include two symmetrical buffer circuits with an output signal that can follow the input voltage to provide bi-directional buffer action for a data path of the bus buffer. The clock buffer can operate in a forward or reverse direction, where the signal direction for the clock signal path in the bus buffer can be controlled with a direction input. The bus buffer can also include an enable circuit for enabling the data path and the clock signal path.
    Type: Grant
    Filed: December 19, 2007
    Date of Patent: November 23, 2010
    Assignee: Hendon Semiconductors Pty Ltd.
    Inventors: David Murfett, Paul Bourne, Philip Tracy
  • Publication number: 20080183919
    Abstract: A bus buffer can include a data buffer and a clock signal buffer. The data buffer for can include two symmetrical buffer circuits with an output signal that can follow the input voltage to provide bi-directional buffer action for a data path of the bus buffer. The clock buffer can operate in a forward or reverse direction, where the signal direction for the clock signal path in the bus buffer can be controlled with a direction input. The bus buffer can also include an enable circuit for enabling the data path and the clock signal path.
    Type: Application
    Filed: December 19, 2007
    Publication date: July 31, 2008
    Applicant: Hendon Semiconductors Pty. Ltd.
    Inventors: Paul Bourne, David Murfett, Philip Tracy, Kay Malcolm, Potter Mark, Crawford John
  • Patent number: 7348803
    Abstract: A bi-directional bus buffer for applications using the I2C and SMBus, or other bus systems operating on similar principles, able to extend the bus load limit by buffering both the SCL and SDA (clock and data) lines, allowing capacitive loads of up to the limit of 400 pF on both sides of the buffer. With the use of an enable function, sections of the bus can be isolated, and then, thorough the use of a number of these buffers, different parts of the system are able to be isolated, and brought on-line successively or in a controlled manner, permitting a controlled start-up, and operation at maximum performance speeds while still having a diverse range of components, operating speeds and loads.
    Type: Grant
    Filed: June 23, 2006
    Date of Patent: March 25, 2008
    Assignee: Integrated Electronic Solutions Pty. Ltd.
    Inventors: Thi Bui, Malcolm Kay, David Murfett, Mark Potter, John Crawford
  • Publication number: 20060290381
    Abstract: A bi-directional bus buffer for applications using the I2C and SMBus, or other bus systems operating on similar principles, able to extend the bus load limit by buffering both the SCL and SDA (clock and data) lines, allowing capacitive loads of up to the limit of 400 pF on both sides of the buffer. With the use of an enable function, sections of the bus can be isolated, and then, thorough the use of a number of these buffers, different parts of the system are able to be isolated, and brought on-line successively or in a controlled manner, permitting a controlled start-up, and operation at maximum performance speeds while still having a diverse range of components, operating speeds and loads.
    Type: Application
    Filed: June 23, 2006
    Publication date: December 28, 2006
    Applicant: Integrated Electronic Solutions Pty Ltd.
    Inventors: Thi Bui, Malcolm Kay, David Murfett, Mark Potter, John Crawford