Aside other nice things about the new Yoga 3 Pro laptop from Lenovo, I am quite fascinated about its charging port that combines both USB and charging port into one.
The power adapter that comes with the laptop has a special charging connector that has two extra pins on each side, matching two extra pins on the Yoga’s charging port. The extra pins make a connection when the charging cord is plugged into the laptop telling laptop that it’s time to feed you more juice. Because of that, you cannot use a regular USB cable to charge the laptop. When a regular USB cord is plugged in, the charging port on Yoga then acts like a regular USB 2.0 port.
And because it’s also colored as yellow, meaning that it’s an Always-On port that supplies power to the gadget even while in sleep mode or off.
Yoga 3 requires 2A at 20V to power up. So if you need an additional power adapter for traveling, look at 40W Lenovo AC adapter in their accessories section. It’s so popular right now that the back order is on 6 weeks. In addition to 2A at 20V, the 40W power adapter also supplies 2A at 5.2V that is enough to charge a phone and tablet.
20V VCC and GND are wired to standard USB VCC and GND pins (pin 1 and 4). There is a third wire inside the cable, colored blue, that connects to both “extra” pins.
I tried to wire black and white connectors of the extra cable to an old Lenovo 20V charger, leaving blue wire unconnected. Yoga 3 Pro won’t charge that way.
If I plug the cut wire into original charger, both white and blue wires provide 5V. Sadly, there is no info on how to make this work (usually it takes a resistor of certain value).
Use 220 ohm resistor between ground and blue. It will eork