automobile alternator?

[Willbe]

Isn't it when the output voltage is zero? (short circuited output)

Assuming (current)x(coil turns) is what provides magnetomotive force, an open field winding assures zero current. A shorted field winding = zero voltage = indeterminate current.

 

[Analog]

So if the input to the alternator is zero , where does this magic o/p current come from ?

my bad - I was hasty in the discussion, I should have said that the maximum output would come when the voltage regulator sees zero. The stator and rotor form a rotational transformer of sorts, so you indeed need current on the stator (field) to generate the maximum output.

 

[Ross Craney]

my bad - I was hasty in the discussion, I should have said that the maximum output would come when the voltage regulator sees zero. The stator and rotor form a rotational transformer of sorts, so you indeed need current on the stator (field) to generate the maximum output.

I think there is a lot of misunderstanding here about how an alternator works. The stator actually is where the generated voltage comes from. The rotor is excited by the voltage supplied by the regulator and creates the magnetic field that causes voltage to be generated in the stator. As the revs increase so the generated voltage increases , the regulator detects this and lowers the voltage to the exciter (rotor) accordingly thus maintaining a constant o/p voltage. On a 90A alternator you can saturate the exciter & actually do arc welding with the o/p

 

[johnsoperV5]

Would it be a solution to sort out hooking an appropriately sized 12 volt Sinewave inverter to the unaltered DC output of a 100 amp alternator?

 

[Ross Craney]

As previously stated the alternator o/p would be best described as full wave rectified AC. Usine an inverter is pretty standard practice but you would need to keep the battery in circuit to both smooth the alternator o/p and supply the exciter windings

 

[Ross Craney]

An alternator circuit if the attatchment works