I am working on a scale model and I want to hook up some LEDs to it. I want to hook up about a total of 10-13 blue LEDs. I want to connect them by an adapter to the wall socket but I am confused by something. If a blue LED runs at about 3v each, I would need about 30v or more. When an adapter says it is a 12v adapter, does that mean that it only gives out 12v? is that 12v the maximum or the minimum that the adapter can give out? Would I need a higher voltage adapter if I want to hook up 10+ LEDs?