How Your Heavy-Duty Alternator Works

Truck parked in parking lot at dusk - How Your Heavy-Duty Alternator Works

The operation of your business depends on your trucks, but in order to keep your business running smoothly, your fleet needs to be well-maintained. One of the parts that go out most frequently in trucks is the alternator. Here, we break down how a heavy-duty alternator works.

Why it’s Important

This small part has a big job: providing the entire vehicle with power and keeping the battery charged. While the alternator is running, the truck is actually running completely off of its generated power. Without the alternator, you would have to use the battery’s stockpile of power, and it wouldn’t hold enough juice next time you wanted to start the truck.

Because it plays such a critical role in the continued operation of your trucks, it’s important to understand what, exactly, an alternator does.

The Rotor and Stator

The rotor and stator is where all the action is happening inside an alternator. Both are wound with wire, and as the rotor spins, a magnetic field is generated and turned into electricity. You’ve probably heard people talk about the brushes inside the alternator; the brushes are what pick up the current so that it will accumulate in the wiring.

Of course, a heavy-duty alternator generates alternating current (AC), hence the name. The problem with this is that your car doesn’t run off of alternating current, which brings us to…

The Function of the Diodes

The diodes aren’t as often discussed as the windings and the brushes, but their job is critical, for, without them, your truck’s system would be completely incapable of using the power generated by these parts. Basically, the diodes force the current to go in only one direction, turning it into direct current (DC). Only then does the current generated inside the alternator become something that the vehicle can use.

What the Voltage Regulator Does

The voltage regulator is a part that frequently causes alternator failure, yet its function is a mystery to many people. But without the voltage regulator, your trucks would run down their batteries when idling, or overcharge them and shorten their lifespans during acceleration.

The voltage regulator operates like a dam on a reservoir, ensuring that just the right amount of juice gets through – keeping the battery fully charged at all times, but stopping short of overcharging it. Voltage regulators used to be mounted outside the alternator, but these days, this critical part is usually tucked away inside the alternator.

The Need for Cooling

Because of the moving parts and the power generated, overheating is a concern in alternators, especially those that have to meet high power demands or that are wedged into small spaces without much air circulation. Since these are both typically factors in modern fleet trucks, their alternators often have external and/or internal fans to help keep the temperature down. If a fan fails, an alternator can overheat rapidly, frying the internal workings and requiring the replacement of the entire part.

The dance that goes on inside of a heavy-duty alternator is a precise one, with all the parts contributing to produce just enough juice to keep each vehicle on the road. With so much riding on these small parts, you can see how important it is to have a heavy-duty alternator that works. Contact Elreg today to find out what alternators your fleet should have, or to request a quote.