Apparatus and method for controlling speed of suction motor in vacuum cleaner

A method of controlling speed of a suction motor in a vacuum cleaner, comprising:

• a dust detecting step of detecting an amount of dust being sucked and outputting pulses corresponding to the detected amount of the dust being sucked;
• a sampling time counting step of counting a predetermined period of time;
• a duty cycle calculating step of calculating a duty cycle of the output pulses during the sampling time;
• and
• a suction motor speed controlling step of controlling the rotation speed of the suction motor as a function of only one variable, said variable being the duty cycle calculated at said duty cycle calculating step.

A method of controlling speed of a suction motor in a vacuum cleaner, comprising the steps of:

• (a) detecting an amount of dust being sucked and outputting pulse signals corresponding to the detected amount of the sucked dust;
• (b) calculating a duty cycle of the output pulses at said dust detecting step for a predetermined period of time corresponding to the amount of dust sucked during said predetermined period of time and calculating a desired speed of the suction motor as a function of only one variable, said variable being the duty cycle;
• (c) controlling the rotation speed of the suction motor to equal the calculated desired speed;
• and
• (d) performing steps (a), (b), and (c) repeatedly in the operation of the vacuum cleaner.

A method of controlling speed of a suction motor in a vacuum cleaner, comprising the steps of:

• (a) detecting an amount of sucked dust and outputting pulse signals corresponding to the detected amount of the sucked dust;
• (b) counting a predetermined period of time;
• (c) accumulating high level holding intervals of the interval pulses at said dust detecting step for the predetermined period of time which is counted at said predetermined time counting step;
• (d) controlling the rotation speed of the suction motor to equal the product of the accumulated high level holding intervals multiplied by a constant;
• and
• (e) a step of performing steps (a), (b), (c), and (d) repeatedly in operation of the vacuum cleaner.

A method for controlling the speed of a motor in a vacuum comprising the steps of:

• (a) detecting objects to be vacuumed;
• (b) creating electrical pulses having two states based upon the detected objects;
• (c) calculating a value representing a first length of time the electrical pulses have been in one of said two states during a second continuous length of time;
• and
• (d) controlling the speed of said motor as a function of only one variable, said variable being said calculated value.

An apparatus for controlling the speed of a motor in a vacuum comprising:

• sensors for sensing objects to be vacuumed;
• electrical pulse generating means for generating electrical pulses responsive to said sensors, said electrical pulses having two states;
• value calculating means for calculating a value representing a first length of time the electrical pulses have been in one of said two stats during a second continuous length of time;
• a controller for controlling the speed of said motor as a function of only one variable, said variable being said calculated value.

An apparatus for controlling rotation speed of a suction motor in a vacuum cleaner, comprising:

• means for detecting dust being sucked through a suction port and generating an electrical signal corresponding to size and an amount of said dust;
• waveform shaping means for changing said electrical signal into a pulse signal in a rectangular waveform;
• a sampling time controller for controlling a predetermined sampling time;
• a duty cycle calculator for calculating a duty cycle for said sampling time by counting a time when said electrical signal is at high level during a predetermined sampling time and dividing a sum of said time by said sampling time;
• means for obtaining a desired rotation speed value for said suction motor in response to said duty cycle calculator;
• and
• means for controlling said rotation speed of said suction motor in accordance with said desired rotation speed value.

A method of controlling a rotation speed of a suction motor in a vacuum cleaner, comprising the steps of:

• a) detecting dust being sucked through a suction port and generating an electrical signal corresponding to a size and an amount of said dust;
• b) changing said electrical signal into a rectangular waveform pulse signal;
• c) counting a predetermined sampling time;
• d) counting a time when said pulse signal is at high level during said sampling time;
• e) calculating a duty cycle for said sampling time when said sampling time has lapsed, by dividing a sum of said time by said sampling time;
• (f) obtaining a desired rotation speed value for said suction motor based on said duty cycle calculated;
• and
• g) controlling said rotation speed of said suction motor in accordance with said desired rotation speed value.