Air Purifier Motor Speed Measurement for Filter Change Timing

The patent replaces the simple time-counting mechanism with a motor speed measurement system. By measuring the motor's rotational speed and calculating average speed over operational periods, the system accurately reflects actual filter contamination levels rather than merely tracking elapsed time. This substitution of mechanical time-tracking with physical performance measurement resolves the contradiction between operational simplicity and measurement accuracy.

The system implements feedback by continuously measuring motor speed and comparing it against reference values to determine when filter replacement is actually needed. The control unit receives speed measurements, calculates average speeds over defined periods, and provides feedback signals indicating whether the filter should be replaced. This feedback mechanism ensures filter changes are based on actual performance degradation rather than arbitrary time schedules, resolving the contradiction between procedural simplicity and performance reliability.

The system utilizes the motor's own operational characteristics (its natural speed variations under different loads) to self-diagnose filter contamination levels. Rather than adding separate sensing equipment to measure contamination directly, the system has the motor effectively measure its own performance through speed variations. This self-service approach achieves accurate contamination assessment while minimizing additional device complexity, as the measurement leverages existing motor behavior rather than requiring entirely new measurement infrastructure.