Editing 1-Wire (section)

=== Power supplies ===
Apple [[MagSafe]]- and MagSafe-2-connector–equipped power supplies, displays, and Mac laptops use the 1-Wire protocol to send and receive data to and from the connected Mac laptop, via the middle pin of the connector. Data include power supply model, wattage, and serial number; and laptop commands to send full power, and illuminate the red or green [[light-emitting diode]]s in the connector.<ref>{{Cite web | url=http://www.righto.com/2013/06/teardown-and-exploration-of-magsafe.html | title="Teardown and exploration of Apple's Magsafe connector" | publisher=rightTo.com | access-date=2017-07-18}}</ref>

Genuine [[Dell]] laptop power supplies use the 1-Wire protocol to send data via the third wire to the [[laptop|laptop computer]] about power, current and voltage ratings. The laptop will then refuse charging if the adapter does not meet requirements.<ref>{{Cite web | url=http://hackaday.com/2014/03/03/hacking-dell-laptop-charger-identification/ | title=Hacking Dell Laptop Charger Identification | publisher=hackaday.com | access-date=2015-11-30}}</ref>