×

Broadcast system for distribution automation and remote metering

  • US 4,322,842 A
  • Filed: 10/23/1979
  • Issued: 03/30/1982
  • Est. Priority Date: 10/23/1979
  • Status: Expired due to Term
First Claim
Patent Images

1. A radio communication system for selectively addressing and controlling a plurality of remotely located apparatus comprising in combination:

  • (A) central controller means adapted to generate digital address &

    control signals for transmission to a local AM radio broadcast station, said signals being synchronized to special sync signals broadcasted by said AM radio station,(B) a local AM radio broadcast station adapted to generate and broadcast special sync signals derived from its master oscillator and adapted to receive and broadcast digital signals received from said controller by modulating the phase of its normally broadcasted radio frequency carrier at small angle subaudible rates that do not suppress and spread its normally unused residual carrier power by more than a predetermined amount nor interfere with normal transmissions of said radio station that are simultaneously broadcasted,(c) a plurality of remotely located addressable digital radio receivers controlling a plurality of external apparatus and tuned to detect and phase-lock to residual carrier frequency of said broadcast station to synchronously demodulate and decode said special sync signals and said address &

    control signals and selectively respond to control said apparatus.

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