Patent ID: 6597589
Filing Date: 2003-07-22
Classification: H02M,Y02B

Abstract:
A power converter for converting an alternating-current power into a directâ€”current power for user by a load, comprising:a rectifier having an input terminal for receiving said alternatingâ€”current power; a singleâ€”stage single-switch input current shaping circuit coupled between an output terminal of said rectifier and said load, which outputs a directâ€”current voltage signal in response to the magnitude of said load; a feedback circuit coupled to an output terminal of said single-stage single-switch input current shaping circuit for converting said direct-current voltage signal into a feedback signal for output, wherein said feedback circuit further comprises a frequency-sampling circuit and a frequency-generating circuit; a pulse width modulation control circuit coupled with said single-stage single-switch input current shaping circuit and said feedback circuit, which outputs a pulse width modulation signal to said single-stage singleâ€”switch input current shaping circuit in response to a signaling level of said feedback signal; and a frequency modulation circuit coupled between said pulse width modulation control circuit and said feedback circuit, which performs a frequency modulation process to said pulse width modulation signal according to said feedback signal to abate an energy concentration effect of the electromagnetic harmonics of said power converter.