图呢？没图如何分析？输出电压范围：Vz(R1+R2+R3)/R3≥Uo≥Vz(R1+R2+R3)/(R2+R3)代入数据：6x500/200≥Uo≥6x500/30015V≥Uo≥10VU1不得小于15+2=17Vu2=17/1.2=14.2V
