How does the alternator put a drag on the engine? Do the little brushes grab the armature more tightly? Does flow of electrons make the armature of the alternator harder to turn?

I mean, the alternator turns at the same rate, plled by the belt, whether the car needs current or not.

Where do the electrons come from, anyway? Why does it seem we don't run out of them?

I suppose I should have taken a course in electricity.

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Semibodacious Transmogrifications a Specialty

1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)

"Time flies like and arrow, yet fruit flies like a banana"
---Marx (Groucho)