Carbon monoxide detecting system for internal combustion engine-based machines

A portable generator comprising:

• an internal combustion engine that generates mechanical power;
• a chassis assembly supporting the internal combustion engine and having a handle for transporting the portable generator;
• an alternator that receives the mechanical power from the internal combustion engine and transforms at least a majority of the mechanical power into electrical energy;
• an output interface that provides the electrical energy to an external device for powering the external device;
• an engine interrupt connected to the internal combustion engine, wherein the engine interrupt is configured to selectively stop the operation of the internal combustion engine;
• a controller in communication with the internal combustion engine and the engine interrupt;
• and
• a carbon monoxide detector in communication with the controller, wherein the carbon monoxide detector provides the controller with signals that are representative of a carbon monoxide level proximate the internal combustion engine;
• wherein the controller uses the engine interrupt to stop the operation of the engine under one of at least two shut down conditions, both of which are evaluated by the controller, including:
• a first shutdown condition in which the controller identifies a magnitude value of the signals over a set time interval, and in which the magnitude value exceeds a predetermined shutoff threshold value;
• and
• a second shutdown condition in which the controller calculates, for signal values exceeding a minimum noise threshold, a trend line having a rate of change value over a set time interval, and in which the rate of change value is one or both of a positive value or a value that exceeds a predetermined rate of change threshold value.