Suction motor control for vacuum cleaner - has dust detector in suction opening giving electrical signals corresp. to amt. of sucked dust

摘要

A wave-form distortion correction unit (20) converts the output signals from the dust detection unit (10) into wave-form distortion-corrected pulse signals related to the amount of dust. A speed control unit (30) computes a speed control value in relation to the actual amount of dust according to a working cycle of the pulses given by the correction unit (20) over a predetermined time. The correction unit has a differentiator (21) for receiving the output signals from the dust detection unit and a comparator (22) comparing the output signals from the differentiator with a previously established reference value to derive the wave-form distortion corrected pulse signal. ADVANTAGE - Size and amount of dust is established more accurately than in control systems of conventional vacuum cleaners and speed of suction motor corresponds to size and amount of sucked-in dust.