Patents Assigned to Siltronics, Ltd.
  • Patent number: 4712112
    Abstract: The invention is a miniature antenna useful for portable radios, pocket pager receivers, etc. A plurality of sequentially wound windings is located on a ferrite core, each winding being connected in series with a capacitor. The resulting series circuits are connected in parallel with each other. Preferably the resonant frequency of each series circuit is approximately 80% to 90% of a receive frequency. An external tuning capacitance resonates with the net inductance of the antenna at the receive frequency. The antenna exhibits low hand effect while maintaining output EMF.
    Type: Grant
    Filed: August 7, 1985
    Date of Patent: December 8, 1987
    Assignee: Siltronics Ltd.
    Inventor: Francis Carr
  • Patent number: 4647866
    Abstract: Apparatus and method for driving a non-centertapped load such as a loudspeaker from a low voltage supply such as a single dry cell, with increased efficiency. A push-pull signal having similar polarity voltage excursions is applied to opposite terminals of the load. Alternate individual terminals of the load which are opposite to the terminals to which the non-idle phases of the push-pull signal are alternately applied are connected to a common terminal via a pair of transistors. The pair of transistors are driven by an amplified representation of the push-pull input signal. Since pulse signals are not used to drive the pair of transistors, capacitors need not be used to eliminate switching transients which would otherwise appear, and increased efficiency results.
    Type: Grant
    Filed: January 17, 1985
    Date of Patent: March 3, 1987
    Assignee: Siltronics, Ltd.
    Inventor: Russell W. Brown