Motor control for a vacuum cleaner
A vacuum cleaner includes a nozzle, an air-filtering dirt receptacle, and a motor. A fan of the vacuum cleaner is configured to be driven by the motor to drive a flow of air that carries dirt from a surface through the nozzle and into the receptacle to clean the surface. A controller of the vacuum cleaner provides a notification to a user of the vacuum cleaner indicative of an excessive amount of dirt in the receptacle when current drawn by the motor drops below a threshold value.
1. A vacuum cleaner comprising:
a nozzle;
an air-filtering dirt receptacle;
a motor;
a fan configured to be driven by the motor to drive a flow of air that carries dirt from a surface through the nozzle and into the receptacle to clean the surface; and
a controller that provides a notification to a user of the vacuum cleaner indicative of an excessive amount of dirt in the receptacle when current drawn by the motor drops below a threshold value;
wherein the flow of air carries the dirt from the surface, through the nozzle and then through the fan and into the receptacle to clean the surface, such that the nozzle is upstream from an inlet of the fan and the receptacle is downstream from an outlet of the fan.
2. The cleaner of claim 1 wherein the notification directs the user to empty the receptacle.
3. The cleaner of claim 1 wherein the notification directs the user to replace the receptacle.
4. A vacuum cleaner comprising:
a nozzle;
an air-filtering dirt receptacle;
a motor;
a fan configured to be driven by the motor to drive a flow of air that carries dirt from a surface through the nozzle and into the receptacle to clean the surface; and
a controller that provides a notification to a user of the vacuum cleaner indicative of an excessive amount of dirt in the receptacle when current drawn by the motor drops below a threshold value;
wherein the controller powers the motor with constant voltage.
5. A vacuum cleaner comprising:
a nozzle;
an air-filtering dirt receptacle;
a motor;
a fan configured to be driven by the motor to drive a flow of air that carries dirt from a surface through the nozzle and into the receptacle to clean the surface; and
a controller that provides a notification to a user of the vacuum cleaner indicative of an excessive amount of dirt in the receptacle when current drawn by the motor drops below a threshold value;
wherein the controller is configured to control the motor to maintain a constant motor temperature.
6. A vacuum cleaner comprising:
a nozzle;
an air-filtering dirt receptacle;
a motor;
a fan configured to be driven by the motor to drive a flow of air that carries dirt from a surface through the nozzle and into the receptacle to clean the surface; and
a controller that provides a notification to a user of the vacuum cleaner indicative of an excessive amount of dirt in the receptacle when current drawn by the motor drops below a threshold value;
wherein the receptacle includes a disposable filter bag, whereby said notification indicates the disposable filter bag should be replaced.
7. A vacuum cleaner comprising:
a nozzle;
an air-filtering dirt receptacle;
a motor;
a fan configured to be driven by the motor to drive a flow of air that carries dirt from a surface through the nozzle and into the receptacle to clean the surface; and
a controller that provides a notification to a user of the vacuum cleaner indicative of an excessive amount of dirt in the receptacle when current drawn by the motor drops below a threshold value;
wherein the controller powers the motor to rotate at different user selectable speed settings, and the threshold value is different for each speed setting.
8. A vacuum cleaner comprising:
a nozzle;
an air-filtering dirt receptacle;
a motor;
a fan configured to be driven by the motor to drive a flow of air that carries dirt from a surface through the nozzle and into the receptacle to clean the surface; and
a controller that provides a notification to a user of the vacuum cleaner indicative of an excessive amount of dirt in the receptacle when current drawn by the motor drops below a threshold value;
wherein the controller is configured to vary a ratio of on-time to total-time of pulse width modulated (PWM) voltage applied to the motor to maintain a parameter of motor operation at a constant value, and the motor current dropping below the threshold is indicated by the value of the PWM ratio.
9. The cleaner of claim 8 wherein the parameter is motor speed, and the controller provides the notification when the ratio drops below a predetermined value.