Working principle of data line: in RS232C, -5V to -15V represents 1, +5V to +15V represents 0; In the TTL circuit, larger than 3V represents 1, and less than 0.2V represents 0. The MAX232 integrated circuit realizes the conversion between RS232C and TTL circuit, in which the ⑧ pins receive the TXD (sending data) signals sent by the 3 pins of the serial port, and then output from the ⑨ pins to the 6-pin IO-RXD (receiving data) of the mobile phone. ⑩ Toes receive IO_TXD (data sending) signals from mobile phones. Output from the ⑦ pin to the serial port on the 2-pin RXD (receiving data) and 1-pin DCD (receiving line signal detection).
MAX232 working power supply is provided by a serial port from a serial port 4, 6, 7, 8 needles of the output of 12 v voltage after two 1 n14148 diode rectifier, after 78 l05 5 v voltage regulator tube voltage output to MAX232 has displayed the feet for integrated piece of work. The 5V power supply also sends to the 3 pins of the plug, which can charge the mobile phone. If you don't want to use the charging function, you can not solder the 3 pins or add a small switch in the front. The four capacitance parameters of MAX232 have an impact on the transmission speed of the data line, and the manufacturer's recommended value luF is used here (MAX232A and MAX3232 are 0. 1uF). T
he capacitors of 470uF and 47uF are the power supply filter capacitors. If you want the circuit to have data transmission indication function, you can add the indication circuit.
The above is the working principle of wushuang data cable. I hope that after reading this, you can have more understanding of wushuang data cable.
