Patents by Inventor Tom Christiansen

Tom Christiansen 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: 8446193
    Abstract: A clock conditioning circuit including a phase detector circuit configured to provide an analog tuning signal indicative of a phase relationship between a reference clock to be conditioned and a generated clock. The controlled oscillator is configured to produce the generated clock, with the generated clock having an output frequency adjustable in response to an analog tuning signal applied to a control signal input of the controlled oscillator. Converter circuitry is provided to produce a digital representation of the analog tuning signal when the mode control circuitry is in a tracking mode. In the event the reference clock is lost, the mode control circuitry switches to a holdover mode so as to provide an analog holdover signal to the control signal input based upon the digital representations produced just prior to the loss of the reference clock.
    Type: Grant
    Filed: May 2, 2011
    Date of Patent: May 21, 2013
    Assignee: National Semiconductor Corporation
    Inventors: Ben-yong Zhang, Tom Christiansen, Christopher Andrew Schell
  • Publication number: 20120280735
    Abstract: A clock conditioning circuit including a phase detector circuit configured to provide an analog tuning signal indicative of a phase relationship between a reference clock to be conditioned and a generated clock. The controlled oscillator is configured to produce the generated clock, with the generated clock having an output frequency adjustable in response to an analog tuning signal applied to a control signal input of the controlled oscillator. Converter circuitry is provided to produce a digital representation of the analog tuning signal when the mode control circuitry is in a tracking mode. In the event the reference clock is lost, the mode control circuitry switches to a holdover mode so as to provide an analog holdover signal to the control signal input based upon the digital representations produced just prior to the loss of the reference clock.
    Type: Application
    Filed: May 2, 2011
    Publication date: November 8, 2012
    Applicant: National Semiconductor Corporation
    Inventors: Ben-yong Zhang, Tom Christiansen, Christopher Andrew Schell
  • Publication number: 20060206239
    Abstract: A two-wire controlling and monitoring system for irrigation of localized areas of soil includes a water pipeline, a plurality of controllable irrigation valves, a plurality of field sensors measuring specific irrigation parameters, and a plurality of localized irrigation control units. Each irrigation control unit has a sensor decoder connected to a specific field sensor and/or a line decoder connected to a specific controllable irrigation valve. The system further includes a controller and power supply unit that applies a first alternating DC voltage signal to a two-wire cable interconnecting the controller and power supply unit and the irrigation control units. The two-wire cable provides power from the controller and power supply unit to each of the irrigation control units, it transmits schedules of instructions to the irrigation control units through the two-wire cable, and it receives the irrigation parameters from the irrigation control units through the two-wire cable.
    Type: Application
    Filed: February 13, 2006
    Publication date: September 14, 2006
    Applicant: S-Rain Control A/S
    Inventor: Tom Christiansen
  • Publication number: 20060116793
    Abstract: A controlling and monitoring system for irrigation of localized areas of soil includes a water pipeline, a plurality of controllable irrigation valves, a plurality of field sensors measuring specific irrigation parameters, and a plurality of localized irrigation control units. Each of the control units has a sensor decoder connected to a specific one of the field sensors and a line decoder connected to a specific one of the irrigation valves. The system further includes a controller and power supply unit that applies a first alternating DC voltage signal to a two-wire cable interconnecting the controller and power supply unit and the control units. The cable provides power from the controller and power supply unit to each of the control units. The controller and power supply unit transmits schedules of instructions to the control units, and receives the irrigation parameters from the control units, through the cable.
    Type: Application
    Filed: November 18, 2005
    Publication date: June 1, 2006
    Applicant: S-Rain Control A/S
    Inventor: Tom Christiansen
  • Publication number: 20060080003
    Abstract: A two-wire controlling and monitoring system for irrigation of localized areas of soil includes a water pipeline, a plurality of controllable irrigation valves, a plurality of field sensors measuring specific irrigation parameters, and a plurality of localized irrigation control units. Each irrigation control unit has a sensor decoder connected to a specific field sensor and/or a line decoder connected to a specific controllable irrigation valve. The system further includes a controller and power supply unit that applies a first alternating DC voltage signal to a two-wire cable interconnecting the controller and power supply unit and the irrigation control units. The two-wire cable provides power from the controller and power supply unit to each of the irrigation control units, it transmits schedules of instructions to the irrigation control units through the two-wire cable, and it receives the irrigation parameters from the irrigation control units through the two-wire cable.
    Type: Application
    Filed: November 18, 2005
    Publication date: April 13, 2006
    Applicant: S-Rain Control A/S
    Inventor: Tom Christiansen
  • Publication number: 20050004715
    Abstract: A two-wire controlling and monitoring system for irrigation of localized areas of soil includes a water pipeline, a plurality of controllable irrigation valves, a plurality of field sensors measuring specific irrigation parameters, and a plurality of localized irrigation control units. Each of the irrigation control units has a sensor decoder connected to a specific field sensor of the plurality of field sensors and/or a line decoder connected to a specific controllable irrigation valve of the plurality of irrigation valves. The system further includes a controller and power supply unit that applies a first alternating DC voltage signal to a two-wire cable interconnecting the controller and power supply unit and the irrigation control units. The two-wire cable provides power from the controller and power supply unit to each of the irrigation control units.
    Type: Application
    Filed: July 7, 2004
    Publication date: January 6, 2005
    Applicant: S-Rain Control A/S
    Inventor: Tom Christiansen
  • Patent number: D518178
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: March 28, 2006
    Inventor: Tom Christiansen
  • Patent number: D457083
    Type: Grant
    Filed: March 31, 2001
    Date of Patent: May 14, 2002
    Inventor: Tom Christiansen
  • Patent number: D457452
    Type: Grant
    Filed: March 31, 2001
    Date of Patent: May 21, 2002
    Inventor: Tom Christiansen
  • Patent number: D457825
    Type: Grant
    Filed: March 31, 2001
    Date of Patent: May 28, 2002
    Inventor: Tom Christiansen
  • Patent number: D462026
    Type: Grant
    Filed: March 31, 2001
    Date of Patent: August 27, 2002
    Inventor: Tom Christiansen
  • Patent number: D470065
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: February 11, 2003
    Inventor: Tom Christiansen
  • Patent number: D470066
    Type: Grant
    Filed: April 12, 2002
    Date of Patent: February 11, 2003
    Inventor: Tom Christiansen
  • Patent number: D470067
    Type: Grant
    Filed: April 12, 2002
    Date of Patent: February 11, 2003
    Inventor: Tom Christiansen
  • Patent number: D471475
    Type: Grant
    Filed: April 12, 2002
    Date of Patent: March 11, 2003
    Inventor: Tom Christiansen