Dangerous condition warning device incorporating a time-limited hush mode of operation to defeat an audible low battery warning signal

A dangerous condition warning device adapted to issue an alarm when a sensed dangerous condition exceeds a predetermined status, which dangerous condition monitoring device is operable from a battery, said dangerous condition monitoring device comprising a dangerous condition monitoring device circuit including:

• A) a processor;
• B) an audio annunciator;
• C) at least one visual indicator;
• D) battery condition monitoring means cooperating with said processor to periodically check the output voltage of the battery under load, said battery condition monitoring means including means:
• 1) for detecting a first low battery condition in which battery failure can be expected after a relatively long period and for issuing a first battery problem indication in response thereto;
• and
• 2) a second low battery condition in which battery failure is imminent and replacement should be undertaken and for issuing a second battery problem indication in response thereto;
• E) audio low battery warning means adapted to drive said audio annunciator to issue an audio warning of about 10 milliseconds duration every minute in response to the issuance of each of said first and second battery problem indications;
• F) visual low battery indicator means adapted to drive said visual indicator to issue a series of five flashes of about 10 milliseconds spaced about 500 milliseconds apart, the first flash of the series of five flashes issued in coordination with the issuance of each brief audio warning;
• G) a manually-actuable switch coupled to said processor;
• H) means responsive to actuation of said manually-actuable switch for inhibiting drive to said audio annunciator because of the issuance of said first battery problem indication for a predetermined period if the first low battery condition is detected;
• and
• I) means responsive to actuation of said manually-actuable switch after said second battery problem indication has issued for preventing inhibiting the drive to said audio annunciator if the second low battery condition is detected.