Patents by Inventor Jonathan L. Kramer

Jonathan L. Kramer 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).

  • Continuous condition sensing system
    Patent number: 4950998
    Abstract: A probe developing an admittance with a material whose condition is to be continuously measured is capacitively coupled with a variable frequency oscillator, preferably one having a digital output stage, for generating a variable frequency signal having a period varying with the admittance developed at the probe. Both the oscillator input and output are capacitively coupled to the probe. In a preferred embodiment, a set point circuit including a plurality of resistors coupled in parallel with the oscillator output and a plurality of switches coupled in parallel with the probe conductor and each with a different one of the resistor, provides easy circuit adjustment for use of the system with a variety of materials. A preferred digital circuit employing a pair of flip flops, fixed timer and one shot generate a fixed period variable duration duty cycle digital voltage level signal for transmission, if desired, or for conversion into a variable current signal.
    Type: Grant
    Filed: July 21, 1988
    Date of Patent: August 21, 1990
    Assignee: Drexelbrook Controls, Inc.
    Inventors: Jonathan L. Kramer, Steven R. Petersen, Herbert A. Shauger, Jr.
  • Remotely calibratable instrument system
    Patent number: 4849754
    Abstract: A two-wire, admittance-responsive instrument system in which a transmitter, receiver and calibrator are connected by a two-wire transmission line is disclosed. The calibrator repetitively transmits a calibration enabling signal causing the transmitter to increment a reference admittance for comparison to a sensed admittance corresponding to a known physical condition. The calibrator monitors the bistable output signals transmitted by the transmitter in the calibration mode, which changes state when the incremented reference admittance bears a predetermined relationship to the sensed admittance. The calibrator may then transmit additional calibration enabling signals causing preload to be established for transmitter operation.
    Type: Grant
    Filed: February 2, 1988
    Date of Patent: July 18, 1989
    Assignee: Drexelbrook Controls
    Inventors: Frederick L. Maltby, Richard G. Hall, Jonathan L. Kramer, Howard S. Hoopes, Steven R. Petersen
  • Remotely calibratable instrument system
    Patent number: 4723122
    Abstract: A two-wire, admittance-responsive instrument system in which a transmitter, receiver and calibrator are connected by a two-wire transmission line is disclosed. The calibrator repetitively transmits a calibration enabling signal causing the transmitter to increment a reference admittance for comparison to a sensed admittance corresponding to a known physical condition. The calibrator monitors the bistable output signals transmitted by the transmitter in the calibration mode, which changes state when the incremented reference admittance bears a predetermined relationship to the sensed admittance. The calibrator may then transmit additional calibration enabling signals causing preload to be established for transmitter operation.
    Type: Grant
    Filed: October 25, 1985
    Date of Patent: February 2, 1988
    Assignee: Drexelbrook Controls, Inc.
    Inventors: Frederick Maltby, Richard G. Hall, Jonathan L. Kramer, Howard S. Hoopes, Steven R. Petersen