Patents by Inventor John Andrew Johnston

John Andrew Johnston 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).

  • Gas discriminating semiconductor sensors
    Patent number: 9618491
    Abstract: Sensing particular gases in a mixture uses precise modulated heating. Sensor relative responses are compared at different temperatures and compared with known relative responses to identify gases and concentrations. Heater current sensors provide feedback control and microprocessor inputs. A processor controls complex impedances and varied frequencies in the sensors. Sensor responses at varied complex impedances and at varied frequencies are compared with known responses at those impedances and frequencies to determine existence and concentration of particular gases. Heater and sensor buses are separate or combined.
    Type: Grant
    Filed: February 27, 2015
    Date of Patent: April 11, 2017
    Assignee: Atmospheric Sensors Ltd.
    Inventors: Mike Kellaway, John Andrew Johnston
  • Gas discriminating semiconductor sensors
    Patent number: 8972204
    Abstract: Sensing particular gases in a mixture uses precise modulated heating. Sensor relative responses are compared at different temperatures and compared with known relative responses to identify gases and concentrations. Heater current sensors provide feedback control and microprocessor inputs. A processor controls complex impedances and varied frequencies in the sensors. Sensor responses at varied complex impedances and at varied frequencies are compared with known responses at those impedances and frequencies to determine existence and concentration of particular gases. Heater and sensor buses are separate or combined.
    Type: Grant
    Filed: November 1, 2011
    Date of Patent: March 3, 2015
    Assignee: Atmospheric Sensors Ltd.
    Inventors: Mike Kellaway, John Andrew Johnston
  • Gas Discriminating Semiconductor Sensors
    Publication number: 20140336952
    Abstract: Sensing particular gases in a mixture uses precise modulated heating. Sensor relative responses are compared at different temperatures and compared with known relative responses to identify gases and concentrations. Heater current sensors provide feedback control and microprocessor inputs. A processor controls complex impedances and varied frequencies in the sensors. Sensor responses at varied complex impedances and at varied frequencies are compared with known responses at those impedances and frequencies to determine existence and concentration of particular gases. Heater and sensor buses are separate or combined.
    Type: Application
    Filed: November 1, 2011
    Publication date: November 13, 2014
    Inventors: Mike Kellaway, John Andrew Johnston