Maintenance warning inhibitor based on time of day

摘要

In an apparatus that issues maintenance warnings, such as the low-battery audio warnings issued by smoke and carbon monoxide detectors, a system for insuring that warnings are issued only at times of day when it is likely that residents will be awake, so as not to interrupt sleep. In the simplest embodiments, the system may comprise an oscillator, a 24-hour timer, and control logic, most of which may be contained in a microcontroller. One embodiment allows manual selection of the time of day of inhibiting warnings by pressing a pushbutton once. In other embodiments the starting time for the issuing a warning is close to the time of day at which the battery was installed, or the time of day that the detector was last tested. The latter embodiments are automatic, and require no user configuration.

主权项

1. An electronic mechanism for use within a device powered by a battery and that provides a warning upon a predetermined condition, comprising:
a. a timer that provides time of day, b. a condition sensor that detects said predetermined condition, c. setting means for receiving a range of time, d. comparison and inhibiting means for comparing said time of day provided by said timer and said range of time for inhibiting said warning when said time of day is within said range of time, and e. a power-on-reset circuit resetting said timer when said battery is installed thereby establishing a reference time, and wherein said range of time setting is predetermined in such a way that the issuance interval of said warning is approximately centered about said reference time, whereby said mechanism issues said warning at a time of day proximate to that time of day when said battery was installed and is automatic and requires no user programming, whereby the issuance of said warning will be inhibited by said comparison means during said range of time, and said issuance of said warning will occur only outside said range of time.