Abstract: In an apparatus for regulating the power consumption of a vacuum cleaner, it is proposed to detect the pulsating alternating current present at the driving electric motor and delivered by a phase-angle circuit by means of a parallel voltage sensor, rectify it, smooth it, digitize it, and, on the basis of data stored in tabular form from a memory arranged in a microprocessor, convert it into a true effective value of the motor voltage; and subsequently to compare it with various associated respective manually defined power data and to activate the phase-angle circuit so that irrespective of fluctuations or different power system alternating voltages or frequencies, motor output is regulated to constant values corresponding to the manual setting.

Abstract: In connection with an automatic control device for the cleaning power of a vacuum cleaner, comprising a blower, a blower drive motor and an associated control circuit for the latter, it is proposed to provide two vacuum switches adjusted to different vacuum threshold value or one vacuum double switch presetting the two vacuum threshold values, and to drive a storage (counter, capacitor), whose output configurations determine the manner in which a phase control circuit, which is connected in series with the blower drive motor, is driven, by a corresponding configuration of the switching conditions of the said switches. It is possible in this manner, with only two existing vacuum switches, to operate the blower drive motor at a predetermined power plateau, without any switching actions, so long as the vacuum generated remains within a predetermined window.

Abstract: A device for controlling the operation of a vacuum cleaner and for signalling the dust bag fill level, the existence a clogged pipe or of secondary air openings, or the like has an air turbine arranged in the exhaust air flow generated by the blower of a vacuum cleaner, downstream of the dust bag, whose rotary speed or the air turbine is detected in a non-contact manner, converted into an electric indication signal and supplied to a control circuit which controls the blower motor. Based upon the rotary speed so detected, it is then possible to determine the momentary operating conditions of the vacuum cleaner and/or the dust bag fill level, to emit signals warning the operator that the dust bag has to be changed, and also to display finely graded percentage statements or applicable text messages for the user. By combining this information with pressure values picked up by diaphragm-type switches, it is possible to accurately determine the operating conditions to be indicated.