The Ford Barn - View Single Post - USB 5v power from Model A 6v geni/battery

marc hildebrant · 06-19-2011, 07:56 PM

Per the USB 2.0 spec, the max current available is 500 mA per device. However, many devices like disc drives, draw more than 500 mA. These devices count on the fact that for say 4 USB outlets, the total from the computer is 2.0 A, and they assume that they can take the total allowed themselves.

The spec. only allows, though, 500 mA.

For the USB 3.0 spec., I lobbyed for more current and got the max to 800 mA per device.

Marc

06-19-2011, 07:56 PM	#18
marc hildebrant Senior Member Join Date: May 2010 Location: Cape Cod Posts: 1,128	Re: USB 5v power from Model A 6v geni/battery Per the USB 2.0 spec, the max current available is 500 mA per device. However, many devices like disc drives, draw more than 500 mA. These devices count on the fact that for say 4 USB outlets, the total from the computer is 2.0 A, and they assume that they can take the total allowed themselves. The spec. only allows, though, 500 mA. For the USB 3.0 spec., I lobbyed for more current and got the max to 800 mA per device. Marc