"220V Cooling Fan" distributed power supply system is no longer a uniform supply of DC power to the system, but a system of different devices, different circuit boards, and even for the same circuit board different circuits with different power supplies. System, low frequency circuits and high-frequency circuits, small and large load current load power lines completely separated. Especially at low voltage and high current loads, "220V Cooling Fan" a higher voltage and then transferred to the nearby load buck DC-DC conversion module supplied to the load. Power to each circuit of the system is relatively independent, reducing high current transmission line, "220V Cooling Fan" the overall efficiency of the system some improvement, and the reliability and the electromagnetic compatibility problems are relatively easy to solve.