×

Electrical power line and substation monitoring apparatus and systems

  • US 4,777,381 A
  • Filed: 05/11/1987
  • Issued: 10/11/1988
  • Est. Priority Date: 04/13/1983
  • Status: Expired due to Term
First Claim
Patent Images

1. A device for monitoring at least one parameter of a power transmission line, including means for sensing values of said parameter, means for processing said values, means for periodically transmitting said values, means for deriving energy from said transmission line for powering said processing means and transmitting means, energy storage means for powering said processing means and transmitting means, means for sensing voltage on said transmission line with no current in said transmission lie and for providing a signal indicating the no current condition, and means responsive to said indicating signal being present for a predetermined time period for reducing the frequency of periodic transmissions.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×