Decided for now it's best to use a 5v ac adapter. I'm not sure what the leds are rated for, and I'm a little worried about blowing them. They're generic buttons you get from Amazon, probably made in China, along with the knockoff Sanwa joys. At any rate, I have plugs that will give me 850mA, 550mA, and 1A. I'll be lighting 6 buttons. Is there a better way to figure out what I'll need besides starting at the lowest current and moving up from there if it's too dim? I'm at a loss not knowing what they can handle.