SWITCHING POWER SUPPLY

PROBLEM TO BE SOLVED: To provide a switching power supply capable of achieving a common component and reducing variations in leakage inductance.SOLUTION: A switching power supply 100 includes an inverter circuit 10 for generating an AC voltage from a DC voltage and first and second transformers for inputting the AC voltage generated in the inverter circuit 10 to primary windings 11a and 11b and outputting a different AC voltage from secondary windings 12a and 12b. The primary winding 11a of the first transformer and the primary winding 11b of the second transformer are connected in series and each comprised of a printed board wiring and foil-like conductors 31a and 31b. The foil-like conductor 31a constituting the primary winding 11a of the first transformer and the foil-like conductor 31b constituting the primary winding 11b of the second transformer are formed of members having the same shape and connected via the printed board wiring.