Which device generates the field control signal for charging rates in a vehicle electrical system?

Which device generates the field control signal for charging rates in a vehicle electrical system?

• A. Battery
• B. Alternator
• C. Inverter
• D. Starter

Answer: (B)

Charging rate in a vehicle’s electrical system is controlled by the alternator through excitation of its field winding. The regulator monitors the system voltage and adjusts the field current to the rotor, which changes the strength of the magnetic field and, in turn, the amount of electrical power the alternator produces. In modern cars, this regulator is usually built into or closely integrated with the alternator, so the alternator is the device that generates and modulates the field control signal to keep charging at the proper rate. The battery is the energy sink and storage, not the source of the field signal; the inverter and starter have different roles and do not regulate charging in the standard system.

Charging rate in a vehicle’s electrical system is controlled by the alternator through excitation of its field winding. The regulator monitors the system voltage and adjusts the field current to the rotor, which changes the strength of the magnetic field and, in turn, the amount of electrical power the alternator produces. In modern cars, this regulator is usually built into or closely integrated with the alternator, so the alternator is the device that generates and modulates the field control signal to keep charging at the proper rate. The battery is the energy sink and storage, not the source of the field signal; the inverter and starter have different roles and do not regulate charging in the standard system.