Patents Assigned to National Electronic Devices Ltd.
  • Publication number: 20060148474
    Abstract: An RF choke for minimizing hum modulation in a coaxial cable system that carries broadband signals along with high amperage 60 Hz AC power signals. The choke contains two conductors wound about a rod core. The first conductor includes two groups of clockwise windings each containing three turns. The second conductor wound counterclockwise also contains two groups of winding one of which contains four turns and the other of which contains three turns. The two connectors are separated by a space of about 0.20? and a 750 ohm resistor is placed in parallel over the second group of winding in the first conductor and a second 510 ohm resistor is placed in parallel over the first group of windings in the second conductor.
    Type: Application
    Filed: December 30, 2004
    Publication date: July 6, 2006
    Applicant: National Electronic Devices, Ltd.
    Inventor: Prabhakara Reddy
  • Patent number: 6339364
    Abstract: A radio frequency (RF) choke having improved insertion loss and reduced modulation hum. The choke includes a core having first and second end portions which have similar magnetization and saturation characteristics, and which may be of equal or unequal diameters. A plurality of turns of a first conductor encircle the first end portion of the core in a first direction to define a first winding. Pluralities of turns of a second conductor encircle the second end portion of the core in the opposite direction to define second and third windings. The numbers and spacings of the turns of the first winding are so related to the numbers and spacings of the turns of the second and third windings that relatively low frequency currents flowing through said windings generate substantially canceling fluxes in the first and second end portions of the core, while relatively high frequency currents flowing through said windings do not generate substantially canceling fluxes in the first and second end portions of the core.
    Type: Grant
    Filed: June 15, 1999
    Date of Patent: January 15, 2002
    Assignee: National Electronic Devices Ltd.
    Inventors: Prabhakara Reddy, George W. DuBois