Electrically-operated backup alarm
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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Abstract
An improved electrically-operated backup alarm for use on mobile construction and industrial machinery, including selectable lower and higher loudness levels, automatically adjustable loudness level with respect to varying ambient noise level in which the alarm is operating, high and low frequency compensation to substantially eliminate high and low frequency signal components of the sensed ambient noise, and compensation for responding to transient signal components of the sensed ambient noise.
43 Citations
15 Claims
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1. An electrically-operated alarm device comprising:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 12, 13, 14, 15)
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8. An alarm device for operation in an environment having ambient noise, said device comprising:
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sound-emitting means for emitting sound at a preselectable loudness level during a first preselected time period; signal conditioning means for producing loudness control signals; timing and control means coupled to the sound-emitting and signal conditioning means for controlling the sound-emitting means during a second preselected time period sequentially following said first preselected time period; said signal conditioning means adjusting the loudness level of sound to be emitted from the sound-emitting means during the next succeeding first preselected time period in response to said loudness control signals representing sensed ambient noise during a third preselected time period sequentially following the second preselected time period; said timing and control means causing the first preselected time period to successively and sequentially follow the third preselected time period. - View Dependent Claims (9, 10, 11)
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Specification