Incompetent employees. The employee of this SC seriously proved to me that the two wires of the MagSafe cable (+16 and -16 volts), the power supply from the MacBook transmits the certification data about the unit to the MacBook. At the same time, I couldn't even answer what kind of detail it does, having previously written: "There are enough chips in apple chargers to take care of this," and the plug, he calls the "plug." I would doubt his professional aptitude. The funny thing is that he claims that in general, this is done by the part responsible for power regulation, which is a microprocessor with 4 KB memory. A TRULY brilliant man