Responder arranged to detect and respond to a smoke alarm by producing a secondary alarm signal

摘要

The invention provides a responder designed to detect and respond to an alarm signal consisting of burst of energy. The responder comprises a processor (9,fig.2), connected to receive signals derived from a microphone (6,fig.2) and programmed to detect 20 a degree of consistency in one or more characteristics of bursts of sound from a smoke alarm (SD,fig.1) before responding. This is preferably done using means 18 for examining measured periods and/or on/off ratios of the sound bursts. The responder is particularly suited for eliminating problems associated with high false alarm rates, high processor power requirements, and the dependency on knowledge of the characteristics of each smoke alarm.