Walter Kidde Portable Equipment, Inc.

Michael W Apperson

John J Andres

Joseph G DeLuca

Larry R Ratzlaff

Chris R Gilbert

Stephen M Ernst

Craig Kleinberg

John Wurtenberger

Presented is a communications protocol for use by interconnected hazardous condition detectors, such as smoke and carbon monoxide detectors for use in dwellings and other structures. This communications protocol provides conventional signaling to indicate the presence of a smoke condition necessitating the generation of a smoke temporal pattern by all interconnected detectors. The protocol further defines a signaling method by which conventional smoke detectors that are incapable of providing temporal patterns other than that required for a smoke alarm condition will not be sent into an alarm mode of operation upon receipt of a signal other than the conventional smoke alarm signal. This communications protocol defines a pulsed signal to indicate a non-smoke alarm condition that is of a duration that will not trigger the conventional smoke alarms. To allow for the transmission of multiple hazardous conditions alarm notifications, as well as the transmission of additional hazardous condition detector control signals, the communications protocol utilizes a multi-bit signal transmitted via the conventional single signal I/O wire of currently existing interconnect wiring. Through the use of an 8 bit alarm signal, multiple hazardous conditions may be signaled as well as operating modes such as test, hush, reset, low battery, etc. Also presented are smoke, carbon monoxide, and combination hazardous condition detectors that utilize the communications protocol presented herein.

Communication protocol for interconnected hazardous condition detectors, and system employing same

A microcontroller-based hazardous condition detector having an intelligent hush feature is presented. The microcontroller controls the operational mode of the detector by monitoring a single user-actuated switch, the inputs from a smoke chamber and a carbon monoxide detector circuit, and the current operating mode of the detector. When in a normal or no-alarm mode, actuation of the switch will cause the microcontroller to place the detector in a test mode of operation. If the detector is in a carbon monoxide alarm mode, actuation of the switch will act to reset the accumulator function of the microprocessor for the carbon monoxide alarm sensing. If the detector is in a smoke alarm mode, actuation of the switch may place the detector in a hush mode if the level of smoke is sufficiently low, or will have no effect if the level of smoke is too high. Once in the hush mode, actuation of the switch will place the detector into the smoke alarm mode. The microcontroller 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. To coordinate this operation, the sensitivity of the detector is not changed in any mode of operation, and the microcontroller monitors both an alarm and a hush threshold.

Microprocessor-based combination smoke and carbon monoxide detector having intelligent hush feature

Growing community of inventors

Chapel Hill, NC, United States of America

Michael W Apperson