Patents by Inventor Nile M. Oldham

Nile M. Oldham 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).

  • Digitally synthesized audio frequency voltage source
    Patent number: 5039872
    Abstract: A method and apparatus for accurately generating a digitally synthesized sinusoidal voltage is started by storing digital values for sine waveforms in a read only memory. A first and second digital to analog converters are connected to the read only memory through latches. The outputs of the first and second digital to analog converters are alternatively switched between the inverting input and the non-inverting input of an operational amplifier such that one of the first and second digital to analog converter is connected to the inverting input while the other is connected to the non-inverting input. The output of the operational amplifier is connected to the inverting input through a variable capacitance, the feedback being determined by the one of the first and second digital to analog converter connected to the inverting input. A clock is used to control the connection of the first and second digital to analog converter to the inverting input and to control the determination of the feedback.
    Type: Grant
    Filed: September 28, 1989
    Date of Patent: August 13, 1991
    Assignee: The United States of America as represented by the Secretary of Commerce
    Inventor: Nile M. Oldham