>>> 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. For analogs: the water bang is a relais without bleeder diode, and a ram pump is a step-up (boost?) converter. 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