Which device is commonly used to regulate the field current in an automotive alternator?

Which device is commonly used to regulate the field current in an automotive alternator?

• A. Diode trio
• B. Regulator
• C. Battery
• D. Stator

Answer: (C)

Regulating the generator’s output is achieved by controlling the current in the rotor’s field winding. That job is done by the regulator, which is usually built into the alternator in modern vehicles. The regulator watches the system voltage and tweaks the field current to keep the output around 13.8–14.4 volts. If the voltage starts to drop, the regulator increases field current to boost generation; if it climbs too high, it reduces field current to lower the output. The battery isn’t the device that regulates the field—it's the load and energy reservoir that the alternator charges. The diode trio and the stator are part of converting and delivering the generated power, not controlling the field current.

Regulating the generator’s output is achieved by controlling the current in the rotor’s field winding. That job is done by the regulator, which is usually built into the alternator in modern vehicles. The regulator watches the system voltage and tweaks the field current to keep the output around 13.8–14.4 volts. If the voltage starts to drop, the regulator increases field current to boost generation; if it climbs too high, it reduces field current to lower the output. The battery isn’t the device that regulates the field—it's the load and energy reservoir that the alternator charges. The diode trio and the stator are part of converting and delivering the generated power, not controlling the field current.