Abstract: A smoke detector monitors one or more internal conditions, such as battery output voltage in detectors that include batteries. Both audible and visible indicators are energized to indicate the presence of the monitored condition or conditions. A switch or a wireless sensor on the detector can be actuated to temporarily suppress the audible indicator provided the battery exhibits an output voltage in a predetermined range, less than that of normal operation.

Abstract: A smoke detector monitors one or more internal conditions, such as battery output voltage in detectors that include batteries. Both audible and visible indicators are energized to indicate the presence of the monitored condition or conditions. A switch or a wireless sensor on the detector can be actuated to temporarily suppress the audible indicator provided the battery exhibits an output voltage in a predetermined range, less than that of normal operation.

Abstract: A low power local alarm indicating system for interconnectable detectors enables a viewer to, after the fact, determine which detector or detectors had previously gone into a local alarm. An alarm latch, such as a bistable multi-vibrator circuit, is set each time the respective detector goes into a local alarm. Subsequently, if the detector's test switch is activated, a local alarm visual indicator is provided. In a disclosed embodiment, the indication is provided by blinking a light emitting diode on the detector, for a predetermined interval. Where multiple detectors are interconnected, each detector that goes into alarm not only sets its local alarm latch and emits a local alarm, it also generates an interconnect alarm signal to the remaining interconnected detectors. The interconnected detectors go into alarm at least for as long as the interconnect signal is present.