Patents by Inventor Fredrick W. Caspari

Fredrick W. Caspari 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).

  • Sensor temperature control in a thermal anemometer
    Patent number: 6905242
    Abstract: A thermal anemometer that separates sensor heating from sensor temperature measurement through a switched sampling technique. This approach demonstrates several advantages over the more typical circuitry employing a bridge, which simultaneously heats the sensor and senses the ambient and velocity sensor temperature. In a thermal anemometer in accordance with the present invention, sensor temperature is determined by sampled measurement of its resistance. Sensor temperature is controlled by varying the voltage applied to the sensor with an error value determined by the difference between actual sensor resistance and the desired resistance.
    Type: Grant
    Filed: January 12, 2004
    Date of Patent: June 14, 2005
    Assignee: Dwyer Instruments, Inc.
    Inventors: Daniel A. Heuer, Fredrick W. Caspari
  • Sensor temperature control in a thermal anemometer
    Publication number: 20040199354
    Abstract: A thermal anemometer that separates sensor heating from sensor temperature measurement through a switched sampling technique. This approach demonstrates several advantages over the more typical circuitry employing a bridge, which simultaneously heats the sensor and senses the ambient and velocity sensor temperature. In a thermal anemometer in accordance with the present invention, sensor temperature is determined by sampled measurement of its resistance. Sensor temperature is controlled by varying the voltage applied to the sensor with an error value determined by the difference between actual sensor resistance and the desired resistance.
    Type: Application
    Filed: January 12, 2004
    Publication date: October 7, 2004
    Inventors: Daniel A. Heuer, Fredrick W. Caspari