Provided is a regulator adapted to the various vehicle alternators of the present invention. The regulator particularly includes a coding circuit and a control circuit. The coding circuit is used to provide the different selectable codes. A laser trimming technology is introduced to form an open circuit over the coding circuit, in order to set a code. The control circuit is used to predetermine the various function selections in accordance with the various codes. The coding circuit includes an amplifier, a first input resistor, and a second resistor. The first input resistor is interconnected to a high-voltage end and an input end of the amplifier in series. The second input resistor is further interconnected to the input end and a low-voltage end in series. The open circuit is particularly formed on the first input resistor or the second input resistor for regulating the output voltage and setting a code.