Anyone know the technical differences between Apple's Charging Spec and "Dumb USB"'s?

[JM Popaleetus]

Looking at this: http://www.amazon.com/dp/B00GC4AJOU/

Does anyone know the actual pin/technical difference for why Apple devices need a different adapter to pull over 1A?

(Tried Googling, either nobody else has asked or I'm choosing the wrong keywords.)

 

[DeviousTrap]

How's this? http://blog.curioussystem.com/2010/08/the-dirty-truth-about-usb-device-charging/

 

[JM Popaleetus]

How's this? http://blog.curioussystem.com/2010/08/the-dirty-truth-about-usb-device-charging/

Perfect! Thanks!

Looks like "Universal" adapter just combines the EU and Low-Power Apple charging circuits, while the "Apple" adapter is strictly Apple's High/Low charging circuit.

Nevertheless, I decided to buy both adapters and a USB power meter to actually test the different power draws. Will report back.