Patent ID: 7282888

Claim:
A driving circuit of an AC fan motor, comprising: an AC to DC converter having a rectifier having an AC power input and a DC power output and converting the AC power to DC power; and a filter connected to the DC power output to output high voltage DC power; a current wave detecting unit connected to the filter; a step-down divider connected to the filter through the current wave detecting unit to obtain low voltage DC power and having a series of multiple resistors connected to high voltage DC power and the filter; a node connected to the series of multiple resistors; and a capacitor connected between the node and ground; a motor driving unit connected to the step-down divider through the current wave detecting unit to obtain the low voltage DC power, and having: two transistors, each transistor having a collector terminal, an emitter terminal and base terminal; a driving IC having a low voltage DC input connected to the node in the step-down divider; two Hall signal inputs; and two controlling outputs connected respectively to the base terminals of the transistors to alternately turn the transistors on and off; and a Hall sensor connected to the Hall signal inputs of the driving IC and having a low voltage DC input connected to the node in the step-down divider; windings having a first winding and a second winding connected to the high voltage DC power and the filter through the current wave detecting unit, and respectively to the collector terminals of the transistors, and each winding having multiple coils; and a harmonic wave elimination unit connected to the high voltage DC power in parallel with the windings.