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, wherein

• the power converter circuit includes a parallel connection of the series connection,
• the apparatus comprises:
• 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;
• 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;
• a wiring pattern which is mounted on the substrate and connects the primary side coil configuring the lower arm transformer and the DC power supply;
• a plurality of upper arm connection sections which connect the upper arm switching elements to the substrate and which are provided on the substrate so as to be arranged in line, when viewing a surface of the substrate from a front thereof;
• and
• a plurality of lower arm connection sections which connect the lower arm switching elements to the substrate and which are provided on the substrate so as to be arranged in line and in a direction in which the upper arm connection sections are arranged, when viewing the surface of the substrate from the front thereof,
• the voltage control switching element is provided so as to form a closed circuit including the DC power supply, the primary side coils configuring the upper arm transformer and the lower arm transformer, the wiring pattern, and the voltage control switching element when being turned on,
• the upper arm connection sections arranged in line and the lower arm connection sections arranged in line are provided in parallel, when viewing the surface of the substrate from the front thereof,
• the upper arm transformer and the DC power supply are provided in an area opposed to the lower arm connection sections with respect to the upper arm connection sections, when viewing the surface of the substrate from the front thereof,
• when viewing the surface of the substrate from the front thereof, the power supply control section is provided in at least one of an area opposed to the upper arm connection sections with respect to the upper arm transformer and, an area which is sandwiched between at least one of the upper and lower connection sections closest to one side of the substrate positioned in a direction in which the upper arm connection sections are arranged, and the one side,
• the lower arm transformer is provided in an area opposed to the upper arm connection sections with respect to the lower arm connection sections, when viewing the surface of the substrate from the front thereof, and
• the lower arm transformer is common to at least two of the lower arm switching elements.