How The Alternator Works ? Let's See Inside the Alternator

 Hi guys welcome back to my website. Today I will show you how the alternator work in our vehicle.

So how the alternator work ? check this out.



We know that fuel is the main material for the engine to run. But How about electricity? Is it possible if the engine hasn’t electricity ?

I dont think so.

Nowdays, electronic devices are closely related to engines. And this electronic device is very dependent on electric power.

Then who provides electricity for the vehicle? Is it the battery?

Battery is not a power supply for vehicles. The reason, the battery is use to store electricity. That means we need another device to produce electricity continuously.

It is the alternator job.

Then how can the alternator generate electricity?

The alternator makes use of the electromagnetic force. When a magnetic field rotates on the coil, the coil will generate electricity.

Don't ask why, because it has a long explanation. Maybe in the next post we will discuss it in specific.



In essence, imagine there is a static coil. In the middle of the coil there is a magnetic field. This magnetic field can be obtained from a permanent magnet or coil. Then, when the magnetic field rotates, the magnetic force will intersect. That activity, triggers the movement of electrons in the static coil or it can be said, the electricity is created.

The alternator illustration.



Generally, the alternator use 3 phase coil as a static coil. This coil is placed circularly on the alternator wall. While the magnetic field is obtained from the rotor coil.

That means, the alternator needs electricity as a trigger. This allows a magnetic field to form and the alternator to generate electricity.

But the electricity generated by the alternator is AC type. While the vehicle requires DC electricity.

This can be overcome by placing several diodes at the output of the alternator. The diodes are assembled like this, so that it not only changes the direction of the current, it also unifies the three static output coils into a line output.


This circuit called the diode bridge and it is mounted on the alternator.

Next, there is a voltage regulator.

This is a component to regulate the output voltage of the alternator. Why should be regulated? The alternator rotates because it is connected to the engine pulley. And we know that the engine pulley rotation is not constant.

When the engine is at high RPM, the alternator will rotate fast. So that the resulting voltage is also high. That is the reason why a voltage regulator must be provided.

The voltage regulator is located at the input of the rotor coil. This device will regulate the voltage that enters the rotor according to the engine RPM. In other words, the charging voltage regulation is done by adjusting the magnetic field strength in the rotor coil.

When the ignition is ON, the rotor coil gets full voltage. So that when the engine start, the alternator will generate electricity at full voltage.

But when the engine RPM increases, the voltage entering the rotor coil is limited. So that the alternator output voltage is not too high. The maximum alternator voltage is 14 Volts.

That’s the explanation about alternator on out vehicle.