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Telemetry alarm system

  • US 3,944,996 A
  • Filed: 08/05/1974
  • Issued: 03/16/1976
  • Est. Priority Date: 08/05/1974
  • Status: Expired due to Term
First Claim
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1. A telemetry alarm system adapted to monitor earth slope stability and to provide an alarm upon the occurrence of earth slope instability, comprising earth slope stability sensing means;

  • means for transmitting electrical signals;

    timing means connected to said sensing means and said transmitting means and adapted to cause the transmitting means to transmit a signal of predetermined time duration and predetermined carrier and tone frequencies upon the sensing of an unstable condition;

    receiver means adapted to receive signals transmitted by the transmitting means;

    decoding means into which received signals are passed to produce corresponding pulses of durations of respective predetermined tone frequency signals received;

    time gate means into which said pulses are passed for determining if the respective pulses are within preset maximum and minimum duration limits and for providing an output when a pulse is within said limits;

    alarm means;

    alarm activating means responsive to output from said time gate means; and

    means for providing power to the system.

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