A few days ago, I bought a USB data cable used to connect this book (occasionally), mainly used to send text messages, really not used to the keypad of the phone. Every time I connect to the battery, everyone knows that the life of lithium current is determined by the number of charging, and more hate is that it is not charged. It is not used for a few days. How to remove charging without affecting data transmission? I have found a lot online, saying that there is only one kind, it is broken the USB power cord, I think it is unlikely, open the data line core - circuit board as shown in the figure:
The back surface of the circuit board has the most important data transmission conversion chip PL-2303, which requires a working voltage. So directly disconnect the USB 5V power supply that can not be found. I tried to break the output of the lifting port, you can find a phone, can also be thin in synchronous battery, but if you send text messages, you suddenly disconnect. Look at the description of the PL-203, it is found that 11 cavity is used to accept information transmitted, and the low level is effective. Only the 5V signal charged to the mobile phone is not only charging, but also the signal that receives the transmitted. So can't be disconnected, then do not supply power, can not be disconnected, the method only one is not 5V voltage when it is connected. Watching the board, knowing the 5V voltage from the USB power supply, after a regulator diode and then transporting to the mobile phone. In front of you, remove the secondary tube, so that the chip has both voltage and output will not be 5V. Take chrome iron, turn off a corner first, let the open circuit. As shown in the figure: Patch connection, OK, SMS is also open, and the phone is not charging. Cool! Note: My data line is used for T39, but other things are small, I mean that most of them are using the same chip, the maximum circuit board is slightly different, the principle Everyone understands, compare Easy.
Well, I wish you success!
