1. The problem statement, all variables and given/known data I'm decent with differential equations for RLC circuits, and I KNOW the stationary current will be zero, but I need help to work it out mathematically, because my maths gets me -2.4A (...) L: 0.05H C: 0.04F R: 3 Ω U (source) = 1 V I've got the transient solution: c1e-10t + C2e-50t Known: i(0+) = 0 (coil prevents instant change in current) i'(0+) = u/L = 20 Once the capacitor is charged up, it will block the current. In other words, the stationary current will be zero. 3. The attempt at a solution So I could simply declare that, on electrical reasoning, but I want to calculate it. The problem is, my calculation is wrong. Something is wrong. Been banging my head against this for a while, hope somebody can help me out! Differential equation: L*i'' + R*i' +1/c*i = u' i''=0, because i'=20 u'=0, because u=1 I call the stationary current A: L*0 + R*20 + 1/c A = 0 A=-20*R*C= -2.4 What have I done wrong? If I lack information, please let me know.