Universal USB Power Supply Kit: 10 Steps (with Pictures) Design Considerations. Many wall warts do not output a commonly used voltage rating used by Parts List. Note: A full parts list is attached to this page. Listing the part, manufacture, part number, Board Layout. The most challenging part of all this wasn't creating the schematic and deciding what Tools Needed. Before we start piecing this together lets gather the tools we'll need for this. Tools: See all full list on instructables Power Supply For USB Devices Circuit Diagram Power Supply For USB Devices More and more equipment is sold that runs off internal rechargeable batteries. Although a matching charger is usually supplied in the package, there are also devices that can only be charged via a USB port.