Insulated power supply apparatus

An insulated power supply apparatus, which is applied to at least one power converter circuit including at least one series connection of an upper arm switching element and a lower arm switching element, comprising:

• at least one upper arm transformers which has a primary side coil connectable to a DC power supply and a secondary side coil which supplies drive voltage to the upper arm switching element, and which is provided on a substrate;
• a lower arm transformer which has a primary side coil connectable to the DC power supply and a secondary side coil which supplies drive voltage to the lower arm switching element, and which is provided on the substrate;
• and
• at least one power supply control section which has at least one voltage control switching element which is turned on or off to apply voltage of the DC power supply to the primary side coils of the upper arm transformer and the lower arm transformer, and an integrated circuit which turns on or off the voltage control switching element, and which is provided on the substrate, wherein
• at least one of the upper arm transformer and the lower arm transformer is provided so as to be adjacent to the power supply control section when viewing a surface of the substrate from a front thereof,
• the apparatus further comprises an electric path which transfers output voltage of the secondary side coil of the transformer provided so as to be adjacent to the power supply control section, to the integrated circuit, and
• the integrated circuit turns on or off the voltage control switching element to perform feedback control so that the output voltage detected via the electric path reaches a target voltage.