Patent ID: 8836257

Claim:
A method of providing sensorless control of a fan motor of a household appliance, the method comprising: cutting a voltage to the fan motor of the household appliance; measuring an electromotive force (EMF) of the fan motor at a predetermined time after the cutting of the voltage to the fan motor; and comparing the measured electromotive force (EMF) to a table, and based on the comparison to the table, determining one of: whether the fan motor was running at a time of the cutting of the voltage to the fan motor based on the comparison of the measured electromotive force (EMF) to the table; a speed of the fan motor at a time of the cutting of the voltage to the fan motor based on the comparison of the measured electromotive force (EMF) to the table; and whether the fan motor is operating below a predetermined or threshold value at a time of the cutting of the voltage to the fan motor based on the comparison of the measured electromotive force (EMF) to the table; and based on the determining, generating, by a microcontroller of the household appliance, a mimicking signal that mimics a Hall effect square wave signal and outputting, by the microcontroller, the mimicking signal that mimics the Hall effect square wave signal.