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Failure alarm device for an appliance

  • US 4,843,378 A
  • Filed: 09/22/1987
  • Issued: 06/27/1989
  • Est. Priority Date: 09/22/1986
  • Status: Expired due to Term
First Claim
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1. An alarm system for indicating fault conditions of an appliance comprising:

  • first alarm means for generating a first alarm signal in response to a first control signal indicative of fault conditions of an appliance, and generating an alarm failure signal when said first alarm means cannot generate said first alarm signal;

    Means for generating a second alarm signal in response to both the fault conditions in said appliance and said alarm failure signal;

    control means within said appliance for generating and applying said first control signal to said first alarm means and for generating a second control signal independently from said first control signal in response to the occurrence of fault conditions in said appliance, said first control signal and second control signal being generated synchronously at separate times and in opposite logic states with respect to each other;

    ON/OFF circuit means for generating an ON signal when the appliance is energized with electrical power; and

    AND gate means having first input coupled to said first alarms means for receiving said alarm failure signal, a second input for receiving said second control signal and a third input for receiving said ON signal, said AND gate means generating an output signal to cause said second alarm means to generate said second alarm signal only when said alarm failure signal, second control signal and ON signal are of the same logic state and are simultaneously applied to the first, second and third inputs thereof.

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