二极管现在多为硅二极管正向压降取0.7V。设电阻R1和R2,R1和二极管串联,并联施加电压为V。1、求R1、二极管支路电流I1 = (V - 0.7 )/ R12、求R2支路电流I2 = V / R23、求总电流I = I1 + I2 =(V -0.7)/R1 + V / R2 = (VR2 - 0.7R2 + VR1 ) / R1 R2总电阻 = V / I = R1 * R2 * V /(VR1+ VR2 -0.7R2)