为R1和R2选择合适的阻值，使得通过每一个二极体的电流都为20毫安培培。

Select resistance values for R1 and R2 such that 20 mA flows through each LED.

youdao

为R1和R2选择合适的阻值，使得通过每一个二极体的电流都为20毫安培培。

Select resistance values for R1 and R2 such that 20 mA flows through each LED.

youdao