说明：  DA 转换 产生三角波 正旋波 梯形波（dac0832)换电路接成同相电压输出形式，其输出电压Vout=IR(1+R2/R1)。
(DA conversion triangular wave generated spinning wave trapezoidal wave (dac0832) for access into the same circuit phase voltage-output type, the output voltage Vout = IR (1 R2/R1).)