Jack Johnson is an electrohydraulic specialist, fluid power engineering consultant, and president of IDAS Engineering Inc., Milwaukee. Contact him at firstname.lastname@example.org, phone (414) 236-5350, or visit www.idaseng.com.
Lenz’s Law explains more than just the “speed voltage,” which also happens to be another moniker for that law. It says an induced voltage will occur anytime there’s relative motion between the conductor and the magnetic field.
An open electrical switch blocks current, whereas a closed switch conducts. A closed hydraulic valve blocks flow, but an open valve allows flow. These are clearly contradictory analogies that are often confounding to those who are seeking to cross-fertilize, so to speak, and learn the other language and concepts. There is a method to this madness, or at least an explanation, that belongs in the pantheon of “No wonder we don’t understand each other.”