Patent ID: 8305784

Claim:
A universal input switching power supply comprising: a signal detecting unit coupled to an external AC power source to detect a high or low line voltage of the AC power source and outputting a detecting signal corresponding to the high or low line voltage of the AC power source; two DC converting units respectively coupled to the AC power source to convert the AC power source to two first DC power sources, wherein a voltage of each of the first power sources is changed according to the detecting signal, wherein each of the two DC converting units has: a full bridge rectifier coulped to the AC power source; and a PFC circuit connected to the full bridge rectifiers, outputting the first DC power source; and a physical wiring and controlling unit connected to the two PFC circuits of the two DC converting units and the signal detecting unit, automatically changing wiring of outputs of the two PFC circuits of the two DC converting units according to the detecting signal from the signal detecting unit, wherein the outputs of the two PFC circuits of the two DC converting units are connected in parallel to outputs a second DC power source, if the detecting signal is corresponding to the high line voltage range, wherein the second DC power source is equal to each of the two first DC power sources; and the outputs of the two PFC circuits of the two DC converting units are connected in series to outputs a third DC power source, if the detecting signal is corresponding to the low line voltage range, wherein the third DC power source is equal to a sum of the two first DC power sources.