Patent Document ID: 4860231
Application ID: 07144682
Patent Flag: 1

Claim One:
1. A technique for calibrating and controlling a variable speed motor operated in response to a microprocessor to regulate the rotation of an air moving device driven by the motor comprising the steps of: choosing a reference torque; at the reference torque determining a reference CFM and RPM; determining the moment of inertia for the air moving device; selecting an arbitrary motor speed input; energizing and operating the motor at the selected arbitrary speed input for a sufficient time to allow the RPM of the motor to stabilize; de-energizing the motor for a short predetermined time period to cause the motor and air moving device to slow down and making two measurements of the angular velocity of the air moving device over the predetermined time period; determining the actual load torque acting on the air moving device over the average actual RPM during the predetermined time period; determining the desired RPM as a function of the actual load torque; and adjusting the motor to the desired RPM to thereby achieve the desired CFM output of the air moving device.