"Cooling Fan Manufacturer" need rectangular wave current, the current rating of the inverter means when the continuous operation is the peak value of the rectangular wave. Induction motor requires sine wave current, the current rating of the inverter continuous operation generally refers to the effective value of the sine wave. In order to maintain control of the inverter on the motor current, the DC voltage between the inverter and the motor should have sufficient induced electromotive force difference. So "Cooling Fan Manufacturer" trapezoidal wave sine wave induced electromotive force induced electromotive force and the induction motor can reach peak are restricted inverter DC voltage. In this case, if we assume that the brushless peak "Cooling Fan Manufacturer" and the induction motor current is equal to the power output of the former is 33% higher than the latter, that is to say, the same rectifier / inverter can drive ratios induction motor output 33% higher than the brushless DC motor.