High voltage series switching power supply circuit

 Regarding the high-voltage series switching power supply, a reader called and said that he hopes to provide a series switching power supply with input AC220V and output DC200V0.2A.

After designing the experiment, the author came up with the circuit shown in the attached figure. Its output voltage is quite stable and the efficiency is over 85%. The working principle of this circuit is the same as above, so it will not be described again here. Component selection: VTl uses IRF740 (400V 10A), VT2 uses C2299 (400V0.5A) or MPSA42 (300V 0.5A), VT3 uses P2298T (400V 0.5A) or MPSA94 (300V0.5A). The inductance of the inductor L can be between 100 and 200 μH. If you want to make your own, you can use Φ0.31mm wire to wind 30 turns on the EI28 ferrite core. There should be a gap in the core. In the picture, the power without R is 1/4W, and VT1 needs to add a heat sink. When the output voltage is 200V, replace it with a fixed resistor based on the actual data adjusted by RP. When the output voltage of this circuit is adjusted to 150V, the load current can reach 1A, and the output voltage is quite stable. If it is used in other necessary situations, the wire diameter of the inductor L should be thickened, and the rest does not need to be changed.