Inventors:
Thomas A. Johnson - Ann Arbor MI
Donald R. Demorest - Fenton MI
Michael J. Thielemans - Novi MI
International Classification:
G08B 2100
G08B 2900
Abstract:
The unburned particulate accumulation within the exhaust for a combustion system, such as the liner of a flue for a stove, is monitored by a circuit which receives a temperature indicating signal from a thermo couple mounted within the flue. The circuit includes comparators which process the temperature signal to determine whether the temperature is within in any of three ranges. When the temperature is within a normal burning range, the elapsed time that the temperature remains within such range is stored as a first count whose magnitude is proportional to the accumulation of particulates. When the first count exceeds a prescribed level, a warning device is activated. When the temperature reaches a higher cleaning range that is sufficient to burn the accumulated particulates, the elapsed time that the temperature remains within such range is stored in a second counter. The first counter is reset when the value of the second counter reaches a prescribed value.
