Patents Assigned to E M X International Limited
  • Inductive loop detector
    Patent number: 4639689
    Abstract: An inductive loop has its frequency of oscillation controlled by means of a counter, a reference frequency source, a comparator, and an attenuator. The frequency of the loop is compared by the comparator to the frequency of the reference source to produce an error signal which controls the attenuator. The amplitude of the output signal of the attenuator is used to adjust the loop frequency to a desired value.
    Type: Grant
    Filed: August 27, 1985
    Date of Patent: January 27, 1987
    Assignee: E M X International Limited
    Inventor: David W. Bartlett