Patents by Inventor Montague C. Borland

Montague C. Borland 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).

  • Balanced input phonograph preamplifier circuit
    Patent number: 4293823
    Abstract: A balanced input phonograph preamplifier circuit according to the present invention incorporates a matched differential pair of transistors having a gain control system therefor and having a load matched to standard phonograph cartridge output characteristics by means of a 47,000 ohm resistor and a capacitor that is designed for the particular cartridge involved. A differential voltage amplifier is defined by the matched differential pair of transistors functioning in conjunction with a differential amplifier which is in the form of an operational amplifier functioning in the differential mode. The output signal of the differential voltage amplifier system is processed by a deemphasis network incorporating a voltage amplifier and a current amplifier that are bridged by a feedback loop that is designed specific to the equalization curve of the Record Industry Association of America.
    Type: Grant
    Filed: August 28, 1979
    Date of Patent: October 6, 1981
    Assignee: Logitek Electronic Systems, Inc.
    Inventors: Lindsey S. Hochberg, Montague C. Borland