MICROPROCESSOR-BASED COMBINATION SMOKE AND CARBON MONOXIDE DETECTOR HAVING INTELLIGENT HUSH FEATURE

摘要

The microcontroller (12) of detector (10) controls the operation mode of the detector by monitoring a switch (18), the inputs from a smoke chamber (14) and a carbon monoxide detector circuit (16), and the current operating mode of the detector (1). In a normal or no-alarm mode, actuation of the switch (18) will cause microcontroller (12) to place the detector (10) in the test mode. If the detector (10) is in a carbon monoxide alarm mode, actuation of the switch (18) will act to reset the accumulator function of the microprocessor (12) for the carbon monoxide alarm sensing. If the detector (10) is in a smoke alarm mode, actuation of the switch (18) may place the detector (10) in a hush mode if the level of smoke is sufficiently low, or will have no effect if the level of the smoke is too high. Once in the hush mode, actuation of the switch will place the detector into the smoke alarm mode. The microcontroller (12) will also place the detector in the smoke alarm mode if the level of smoke increases beyond a certain limit and after the expiration of a hush mode time limit.