Computer USB port to mobile phone interface conversion circuit

This circuit uses the USB port to provide the working voltage for MAX3232. The specific parameters of each component in the circuit are shown in the figure. LED1 and LED2 use ordinary green light-emitting diodes; J1~J3 should use better quality interfaces according to the actual space size, resistor R1 should use 1/16W, C1~C5 capacitors should use 10V withstand voltage electrolytic capacitors, voltage regulator diodes should be between 3 and 5V, and U1 should use MAX3232CPE package DIP16.

This is a converter that is suitable for most models of mobile phones (such as Motorola T191, Samsung SGH600, ErICsson 218, NEC 808, Siemens S25, etc.). The specific connection method at the mobile phone data port depends on the mobile phone. After the circuit connection is correct, the PC and the mobile phone can communicate through PC-tool or the mobile phone's downloaded software.