Abstract text

An electronic system for controlling a fan motor includes a microcontroller and a drive circuit. The microcontroller draws power from a first voltage source and generates control signals for sending drive current to stator coils of a fan motor via the drive circuit. The electronic system further includes a second voltage source to provide the microcontroller with an amount of energy sufficient to operate for a short period of time when the voltage of the first voltage source drops below a predetermined level. The microcontroller is configured to detect when the voltage level of the first voltage source drops below a given level and generates control signals for the drive circuit to discharge energy in the stator coils of the fan motor to quickly stop operation of the fan motor within a short period of time.