Patent ID: 6977478
Filing Date: 2005-12-20
Classification: H02P

Abstract:
1. A method for controlling a single phase motor comprising: (i) driving a single phase motor using a motor drive signal in a first mode, the first mode comprising one of a square wave mode and a pulse width modulation mode; (ii) transitioning the motor drive signal from the first mode to a second mode, wherein the second mode comprises the other of the square wave mode and the pulse width modulation mode, and wherein the transitioning commences after motor speed reaches a first centrifugal switch limit for the motor, the first centrifugal switch limit comprising a lower centrifugal switch limit when the first mode comprises the square wave mode, and an upper centrifugal switch limit when the first mode comprises the pulse width modulation mode, wherein the transitioning includes employing a real time motor model to effectuate transition of the motor drive signal from the first mode to the second mode, and a sampling rate for sampling the real time motor model; (iii) modifying the sampling rate for the real time motor model during the transitioning; and (iv) driving the single phase motor using the motor drive signal in the second mode after motor speed has reached a second centrifugal switch limit, the second centrifugal switch limit comprising the other of the lower centrifugal switch limit and the upper centrifugal switch limit.