I own the patent on a counterfeit detector we may sell to a large chain of retail stores. Normally the counterfeit detector is powered by a wall adapter but the chain wants to power the detector from a computer cash register using a USB 2.0 port. The USB ports operate at 5VDC with a maximum of 500mA. My device will use all of that and maybe a little more amps. Perhaps as much as 550mA. We have tested it and it works fine. I’m worried however that we may fry the cash register motherboard. It’s been my experience in the past that if a device requires too much current on a USB 2.0 port it just won’t work. Is that the case or can we fry the cash register motherboard?