Patent ID: 7210194

Claim:
An airflow sensor system adapted for monitoring air inlet airflow and air outlet airflow of a vacuum cleaner, comprising: a vacuum cleaner air duct including an air inlet and an air outlet, wherein the air duct conducts a vacuum airflow generated by the vacuum cleaner; a bypass tube including a first end connected to the air duct between the air inlet and the air outlet and with the bypass tube including a second end communicating with an external air, wherein the bypass tube conducts a bypass tube airflow; and an airflow sensor positioned at least partially in the bypass tube, wherein the airflow sensor is configured to generate a normal voltage differential range when the bypass tube airflow is within a predetermined normal airflow range, configured to generate an input blockage voltage differential range when the bypass tube airflow is greater than the predetermined normal airflow range, and further configured to generate an output blockage voltage differential range when the bypass tube airflow is less than the predetermined normal airflow range.