以单片机为核心电路。让其在按键的作用下产生0到99的二进制数。用DAC0832作D/A转换器件。转换后的电压作为运放OP0的输入。经过运放扩展得到要求的电压。再经过具有很大电流输出能力的三端稳压lm317扩展电流。使电流也能达到要求的指标。同时单片机还起到驱动显示的功能。-core microprocessor circuit. Giving him the keys to the effects of 0-99 have a binary number. DAC0832 used for the D/A conversion device. After converting the voltage operational amplifier OP0 as input. After the expansion to be operational amplifier voltage requirements. After another great current output capacity of the three-Regulators lm317 current expansion. The electric current will also achieve the required targets. SCM also played while driving showed that the function.