Patent ID: 7894215

Claim:
An AC/DC conversion device, comprising: a power factor correction circuit receiving a first voltage, comprising: a switch; and a power control chip for receiving a spread spectrum synchronization signal, wherein the power control chip controls the switch by a control signal according to a variable frequency of the spread spectrum synchronization signal to output a second voltage; and a flyback converter for receiving the second voltage and accordingly generatinag output voltage and outputting the spread spectrum synchronization signal, the flyback converter comprising: a power module chip; and a transformer, comprising a first primary coil, having one end for receiving the second voltage and having the other end for receiving a second control signal of the power module chip, a secondary coil for generating a third voltage according to the second voltage, a second primary coil, having one end coupled to a low voltage, for generating a fourth voltage according to the second voltage, and an auxiliary coil, having one end coupled to the one end of the second primary coil which is coupled to the low voltage, for generating the spread spectrum synchronization signal according to the second voltage.