Patent ID: 6940241
Filing Date: 2005-09-06
Classification: G05B,H02P

Abstract:
1. A method for controlling a drive motor that is coupled to a damper that has a closed position and an open position, wherein the damper is biased toward the closed position with one or more springs that produce a relatively linearly increasing bias force as the damper moves toward the open position, the drive motor driving the damper toward the open position against the bias force, the method comprising: providing drive power to the drive motor to move the damper toward the open position against the relatively linearly increasing bias force, the drive power increasing relatively linearly with a slope as the damper is moved toward the open position to overcome the relatively linearly increasing bias force of the one or more springs; determining when the drive motor stalls at a stalled position by detecting an increase in drive power that is not consistent with the slope of the drive, power; and when the determining step determines that the drive motor has stalled, reducing the power provided to the drive motor.