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Automatic transfer control device and frequency monitor

  • US 4,231,029 A
  • Filed: 02/28/1978
  • Issued: 10/28/1980
  • Est. Priority Date: 02/28/1978
  • Status: Expired due to Term
First Claim
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1. Apparatus for monitoring the frequency of an alternating current power source, comprising:

  • means for measuring the frequency of said source during each cycle;

    means having an address input and a data output for storing a plurality of limit values;

    means connected to said measuring means and said storage means for comparing measured and stored values;

    means connected to said comparing means for generating an alarm signal when a measured value falls outside a limit value;

    and means connected to said storage means for selecting alternate limit values to present to said comparing means on alternate cycles, whereby alternate testing functions are performed on alternate cycles.

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