What is the primary method for regulating the voltage output of an alternator?

The primary method for regulating the voltage output of an alternator is through the voltage output of the DC exciter. The DC exciter is responsible for supplying direct current to the rotor windings of the alternator. By controlling the amount of current supplied to the rotor, the strength of the magnetic field can be adjusted, which directly influences the voltage output of the alternator.

When the load on the electrical system increases, the voltage may drop; in response, the voltage regulator adjusts the exciter's output to increase the current feed to the rotor, thus strengthening the magnetic field and raising the alternator's voltage output. This feedback mechanism is crucial for maintaining a stable voltage level under varying load conditions, ensuring that the electrical systems of the aircraft operate effectively.

In contrast, while the speed of the alternator can affect the generated voltage, it is not a primary regulator method; rather, it is a secondary effect of the excitation process. The resistance in the rotor windings does play a role in the overall efficiency and performance of the alternator, but it does not serve as a means of voltage regulation. Lastly, while the type of battery connected can influence system performance, it does not directly regulate the alternator's output voltage.

Therefore, the