Detecting the audible alarm of residual smoke detectors and its applications

A novel digital signal detection technology has been implemented in low-power, low-cost large-scale CMOS integrated circuit technology. Standby power for this spatial dual-diversity two channel receiver is less than 10 microamperes at three volts, permitting the receiver to be battery-powered for over one year by a set of standard alkaline flashlight batteries. This signal processing technology is downward compatible with most of the tens of millions of smoke detectors already installed and operational in residences worldwide, and upward compatible with battery powered smoke detectors now being marketed and sold throughout the US and the world