High- and low -voltage input balancing power factor correction circuit

[0012] This embodiment is a preferred implementation mode of the present invention, and other principles and basic structures that are the same or similar to this embodiment are within the protection scope of the present invention.

[0013] Please see attached figure 1 , the switching power supply circuit used in the present invention has the same structure as the switching power supply circuit in the prior art. It is all input AC mains power through an AC input module, and then after the rectification and filtering of the EMI filter module and the pre-stage rectification filter module, it becomes into direct current, and then divided into two paths, one of which is the power branch, and the other is the control branch. The power supply branch is input to the transformer after passing through the PFC step-up circuit module and the LLC circuit module. After the output of the transformer is rectified and filtered by the post-stage rectification and filter circuit module, it outputs