Hi , maybe a pretty simple question and about things that we have long used and know well but is there a electric motor or generator that is truly DC? As much as I think there isn't because either to create , induce electricity in windings (generator) u got to have a changing magnetic field which in turn creates changing alternating current AC right? And in dc motors like the BLDC (brushless dc) again the moving of the magnetic rotor is made by changing the phase and PWM, sorry if I make some mistakes. The brushed dc motor operates from true DC I guess. Tell me how much am I right and is there something to add? P.S. Also doesn't in BLDC the rotor bearings experience very little friction as the rotor is held precisely in middle all the time when it operates by the magnetic field ?