How much current flows through the alternator brushes?
a. All of the alternator output flows through the brushes
b. 25 to 35 A, depending on the vehicle
c. 10 to 15 A
d. 2 to 5 A
The Correct Answer and Explanation is :
The correct answer is d. 2 to 5 A.
Explanation:
The alternator in a vehicle is responsible for generating electrical power, which is used to charge the battery and power various electrical systems in the vehicle. It uses a rotating magnetic field to produce alternating current (AC), which is then converted to direct current (DC) by the rectifier.
The alternator consists of a rotor (the rotating part) and a stator (the stationary part). The rotor is equipped with brushes that make contact with a slip ring, which allows current to flow to the rotor windings. The current supplied to the rotor creates a magnetic field that induces an electric current in the stator coils.
The key point here is that the brushes provide current to the rotor windings to generate the magnetic field. The amount of current flowing through the brushes is relatively low compared to the alternator’s overall output. Typically, the current flowing through the brushes is in the range of 2 to 5 amperes. This current is used to energize the rotor windings to create the magnetic field necessary for the alternator to produce electricity.
The total output current of the alternator (often 50-100 A or more depending on the vehicle) is much higher, but this is generated at the stator and not directly through the brushes. Therefore, the amount of current flowing through the brushes is much lower and is generally within the range of 2 to 5 A.
While the alternator’s total output current depends on the vehicle and its electrical demand, the current flowing through the brushes remains relatively small because it only powers the rotor windings, not the vehicle’s electrical load.