A method of power factor correction is disclosed. The method uses the slope of the voltage waveform to determine the phase angle of the voltage. Based on the phase angle, a current waveform is generated that is in phase with the voltage. The slope of the voltage signal is calculated as the derivative of voltage with respect to time. The resultant current signal is in ratio with the voltage signal. Additionally, the current signal has zero or near zero phase displacement with respect to the voltage signal. Repeatedly performing the steps of the method allows a continuous current signal to be provided. As load characteristics change, the method quickly adapts the power to compensate. As a result, reliable and effective power factor correction is achieved.