Microchip Technology Inc.

Wheelock, Inc.

Erik Johnson

John M Yerger

Joseph Kosich

Luy B Nguyen

Shawn Patrick Keeney

William King

Jonathan Corbett

Supervision and testing of a carbon monoxide (CO) alarm using an application specific integrated circuit (ASIC) and microcontroller. Wherein an electrochemical CO sensor is isolated from its detection circuit and a voltage charge is changed thereon then the CO sensor is reconnected to the detection circuit, wherein the voltage charge on the CO sensor returns to an equilibrium state over time. From the voltage versus time results a determination is made as to whether the CO sensor and CO detection circuit are functioning properly. All test and control circuits may be provided by the ASIC.

Carbon monoxide alarm supervision

A plurality of hazard alarm devices are in spatially diverse locations and coupled together with an input-output bus. An interconnect protocol enables non-originating alarm devices to synchronize their audible alert tone pulses with audible alert tone pulses from an originating alarm device in a local hazard alarm condition. Hence, all audible alert tone pulses start sounding substantially together with allowances for signal contention and arbitration between the spatially diverse alarm devices.

Temporal horn pattern synchronization

A plurality of hazard alarm devices are in spatially diverse locations and coupled together with an input-output bus. An interconnect protocol enables non-originating alarm devices to synchronize their audible alert tone pulses with audible alert tone pulses from an originating alarm device in a local hazard alarm condition. Hence, all audible alert tone pulses start sounding substantially together with allowances for signal contention and arbitration between the spatially diverse alarm devices. The originating alarm device continuously sounds its pattern of audible alert tone pulse groups without interruption, while the non-originating alarm devices periodically pause sounding a group of their audible alert tone pulses. The originating alarm device may be found by listening for the alarm device that is continuously sounding audible alert tone pulse groups without pause.

Automatic audible alarm origination locate

The present invention is an ASIC-controlled alarm unit. The ASIC circuit performs all the necessary control functions to provide audible and visual signaling when used with external horn and strobe circuits.

Growing community of inventors

Philadelphia, PA, United States of America

Erik Johnson