1. The problem statement, all variables and given/known data I have a LED Given: u-i-characteristic curve -> thus the wavelengh It's Part of a curcuit. Also (After the LED) There is a resistance of R (known) An a capacitor, (known) 2. Relevant equations If i have a Voltage of U, how can i find the current Running through the LED and the voltage Inside? 3. The attempt at a solution I tried Kirchhoff law for meshes but it wont work... Anybody have another idea?