Looking at an analytical schematic of a generic dc electric motor (Fig. 15, left), we see the battery power supply, stator field coil, an electrical resistance (RA), and the electrical circuit account for the electrical resistance in the armature circuit. A “dependent generator” in the electrical portion accounts for the back electromotive force, or emf (speed voltage), caused by the rotor coil(s) spinning within the electromagnetic soup into which it’s immersed. The spinning coils move in the magnetic field and generate a dependent voltage...
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