Patent ID: 7280374

Claim:
A single-stage power factor correction circuit, comprising: a first rectifier, with an end coupled to a line input terminal; a second rectifier, with an end coupled to a neutral input terminal; a full bridge rectifier, having a third rectifier, a fourth rectifier, a fifth rectifier and a sixth rectifier, having a positive electrode coupled to said line input terminal, and a negative electrode coupled to said neutral input terminal; a capacitor, with an end coupled to a negative electrode of said fifth rectifier and another end coupled to a positive electrode of said sixth rectifier; a seventh rectifier, having a positive electrode coupled to an end of said capacitor; a transformer, having a first primary coil, a second primary coil and a first secondary coil, and an end of said first primary coil being coupled to a negative electrode of said seventh rectifier and another end connected with said second primary coil in series; and a switch, being a three-terminal component and having a first terminal coupled another end of said second primary coil, a second terminal coupled to a control signal, and a third terminal coupled to another end of said capacitor, for receiving said control signal to turn on or off a circuit.