Which alternator component turns on the alternator when voltage drops below a preset level?

The voltage regulator is a critical component in an alternator system that ensures the voltage output remains within specified limits. When the voltage drops below a preset level, the voltage regulator activates or "turns on" the alternator to maintain the necessary electrical supply. It continuously monitors the voltage level in the electrical system and makes adjustments accordingly. If the voltage falls below the defined threshold, the regulator signals the alternator to begin producing electricity, allowing the system to function properly and avoid issues that could arise from insufficient voltage.

The other components play different roles within the electrical system. The stator is responsible for generating alternating current as the rotor spins. The crank relay acts as a switch that connects the battery to the electrical system, and the diode bridge converts the alternating current generated by the alternator into direct current. While each of these components is important for overall operation, the voltage regulator specifically manages the alternator's activation based on voltage levels.