> Yes, but that's only one property of inductance, and it only > works with "sudden stop", not "sudden start". It does: a mass of water will not suddenly start flowing. Inertia will take care of that. > or the reverse "kick" when current flow stops and the magnetic > field collapses. It does. The reverse kick is what makes the ram pump work. And it is what causes the water bang. Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: www.voti.nl/hvu -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist