I have been trying to figure how a commuter diode effectively works in a circuit with a coil. I know that once the electric/magnetic field collapses in the coil after the current is cut to it that it induces a current in the opposite direction on the diode, which can only travel one way. But when trying to read up on an article with diagrams on this fairly simple circuit, I either got really confused or the people drew the diagram wrong. Check out this very small article to see what I am talking about: Inductor commutating circuits. Shouldn't the 4th diagram (the post-collapse diagram) have the current arrows going in the opposite direction and the polarity signs on the diode switched (thus staying the same in the 3rd diagram - because the diode cannot switch polarity)? Or am I just reading it wrong. The current in a diode travels in the direction where the arrow symbol points, right? Maybe one of you could help me out in trying to understand how that circuit works. It seems simple but I can't figure it out with that article.