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Electrically-operated backup alarm

  • US 4,603,317 A
  • Filed: 11/08/1982
  • Issued: 07/29/1986
  • Est. Priority Date: 11/08/1982
  • Status: Expired due to Term
First Claim
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1. An electrically-operated alarm device comprising:

  • oscillator means for producing electromagnetic signals;

    signal conditioning means coupled to the oscillator for processing signals received therefrom;

    power amplifier means coupled to the signal conditioning means for amplifying signals received therefrom; and

    audio transducer means coupled to the amplifier means for emitting sound at preselected loudness levels in response to signals produced by the signal conditioning means, for sensing ambient noise, and for producing signals in response to sensed ambient noise in the environment in which the alarm device is operating;

    said signal conditioning means also producing control signals for automatically limiting the lower and higher loudness levels of the emitted sound at preselectable levels, and for producing loudness control signals to automatically adjust the loudness level of sound emitted by the audio transducer means to a substantially constant preselectable level above a preselectable range of sensed ambient noise in response to signals representing sensed ambient noise received from the audio transducer means.

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