Switched-mode power supplies

Switched-mode power supplies can also be substantially smaller and lighter than a linear supply because the transformer can be much smaller. This is because it operates at a high switching frequency which ranges from several hundred kHz to several MHz in contrast to the 50 or 60 Hz mains frequency used by the transformer in a linear power supply. Despite the reduced transformer size, the power supply topology and electromagnetic compatibility requirements in commercial designs result in a usually much greater component count and corresponding circuit complexity.