How Do Alternators Work?

By Adam Archer

Before you head down to the parts store for a new alternator make sure you check a few connections on the battery terminals and learn how they work.

Have you ever wondered how the alternator in your car works. Your car has and electrical system that sends power the most important essentials, such as your headlights, interior lights dash lights and so on and other non-important things as the radio ( you may not agree there), air conditioning , and all of those other things that we couldn't imagine living without and really depend on. Have you ever thought about where that power comes from? Most people would think it comes from the battery, now that's partially true.

But that is just one of the sources, so if you think about it in all actuality the power comes from your gas tank. And the link from the gas tank to the battery is called an alternator. It starts with power from the crankshaft which turns the"fan" belt, or the serpentine belt and turns the alternator. So, the main function of the alternator is to convert power from the gasoline engine that drives you along the road, to electrical energy to keep the battery in tip-top condition.

Although Alternators vary by manufacturer, there are two elements common to all alternators; the stationary stator and the rotating rotor. The stator consists of three sets of individual windings wound around a laminated circular iron stator frame. Each individual winding is made up of seven coils, which in turn are made up of several individual loops all connected in series. Each coil and each loop are connected so as to increase the total voltage output. Each group of windings has only two leads, one for current to flow in, and the other for current to flow out.

Although it may vary by manufacturer, most leads are wired in a Y-configuration, in which the three sets of windings each occupy 1/3 of the stator. This means that each group of windings produces energy during 1/3 of each revolution. Since each revolution is divided into three steps, each step can be thought of as a phase, each phase occupying 120 degrees of the 360-degree circle. Due to the nature of three-phase alternating current, the type of energy produced by the interaction of the stator and the rotor is continuously variable with respect to time. The rotor is typically composed of a drum-shaped coil of wire, a pair of iron interweaving cups, a shaft, and two slip rings to connect the coil of wire to the car's battery. Since vehicles need to see DC, Diodes become extremely necessary.

Since AC is continuously alternating between positive and negative, diodes can be used so that only one positive and one negative is output. Basically, as the rotor poles turn within one of the stator coils, current flows first within one direction, and then in another. (During the first 180 degrees, of rotation, the current direction is positive, and during the second 180 degrees the current direction is negative). Using diodes to convert current from AC to DC is also known as rectification, and in most alternators, six diodes (two for each phase) are used.

Once you have the current converted over to DC, the last component required is a voltage regulator to determine how much energy is needed to be output from the diode bridge. (The diode bridge is the combination of all six rectification diodes, also referred to as a rectifier bridge). The sensor for the regulator is usually connected to the positive post of the battery and when it senses a low voltage condition, allows more energy to flow in the rotor coil, creating more energy in the stator coils. It does this through a series of points, raising the points off of the contacts to allow less current to flow, or dropping points onto the contacts to increase current flow.

How can you tell when your alternator is going bad? Most of the time the alternator dies slowly. Each of the three sections of the alternator generates its voltage out of phase with the other two sections. Each of the three phases has its own windings in the alternator and each of the windings has its own pair of diodes. Each of these windings and/or diodes can fail, one set at a time. If this happens the alternator can still charge the battery, but only with a limited current, approximately 2/3 of its original capacity if one system fails.

If two systems fail, then it puts out only 1/3 of its rated capacity. And all that means to you is that you can go a long time on a half alternator. Chances are if you don't need headlights or air conditioning or other high current accessories, you would never know that the alternator was dieing!

About The Author

Paul Archer is author and owner of Performance Means Everything and welcomes everyone to enjoy the site and watch it grow. If you would like to know more about Performance please visit the site.

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How To Know Your Car Alternator Is Bad

By Everdrives123

Your car alternator is a part of the vehicles charging system. If you turn the ignition and the battery fails to crank the engine, the problem may be with the battery itself. However, it is also possible that the alternator is no longer capable of holding a charge. When there's a problem with the alternator, the battery will be unable to send a current to the engine. In this article, I will explain an easy way to identify whether your car's alternator is going bad (i.e. not charging properly). I will also describe a few factors that can cause your alternator to become incapable of holding a charge.

Identifying The Problem

You can usually tell whether the charging problem is your battery or the alternator by watching your car's headlights. Here's how: start your car and turn your headlights on. With your car in "Park," gently put pressure on the gas pedal. If you don't see any change in your headlights' intensity, your charging system is working properly. However, if you notice that your headlights become dimmer when you press on the gas pedal, it means that they're being powered by the battery. Your alternator isn't producing a current.

On the other hand, if the headlights grow brighter, it means your alternator is producing a current, but not very much. In fact, it may not be generating enough to keep the battery properly charged when your car is idling.

This method is not infallible for identifying a bad alternator, but it works most of the time.

What Can Cause A Bad Alternator?

Even though alternators are generally sturdy, there are many reasons why they can stop charging properly. They're often susceptible to heat. If you've been driving long distances in extremely warm weather, they can lose their ability to produce a current. They can also be damaged from voltage irregularities. For example, if you jump start a car and cross the jumper cables, the current can overload the alternator.

Also, its ability to produce a full current can be affected if one of the diodes goes bad. The diodes are essential for converting the output from AC to DC. If one of them is damaged or burns out, the alternator's output can be diluted.

If your alternator becomes incapable of holding a charge or producing a viable current, take your car into a service center to have the unit tested. If there is a charging problem, you probably will not be able to have it repaired. Most technicians will consider doing so to be too much effort. In that case, plan to invest in a new or remanufactured unit.

About The Author

For all your Guaranteed used car parts and used transmissions needs the leader in parts is http://www.everdrive.com

Basics Of A Car Alternator

By Everdrives123

Decades ago, alternators were known as generators, but both do the same basic job: they power other components. If it goes bad, your car will continue to work, for awhile (I'll explain how below). But, it plays an important role in the operation of your vehicle and if it fails, you should still have a mechanic replace it. In this article, I'll describe what this component does, the things that can go wrong with it, and the steps you should take when it malfunctions.

What It Does

Think of all the parts in your vehicle that need power: the ignition coils, car stereo, A/C system, headlights, and more. Most drivers think that their car battery is what delivers power to all of these components. In truth, it does. But, there's actually a lot more going on than most people realize. Enter, your alternator.

When you start your car, the battery generates an electrical current that ultimately cranks the engine. But, while driving, the battery needs a continuous source of energy. That energy comes from the gas tank. Here's how it works: your engine requires gas to operate. So far, so good. The crankshaft produces power which turns the serpentine belt. The belt turns the alternator which converts power from the engine into an electrical current that keeps the battery powered. See how it all begins in your gas tank?

How It Fails

What happens when this component malfunctions? Well, nothing immediately. That's because your battery can actually maintain a small reserve of juice to keep everything running, including the engine. If the part fails, turning off non-essential components (for example, the A/C, stereo, etc.) will help the battery conserve energy, allowing your vehicle to run longer. Eventually, the battery will go dry and your engine will stop turning because there's no energy left to power it.

A number of factors can contribute to an alternator not working properly. For example, if the serpentine belt becomes broken or loose, it can reduce the part's electrical output to the battery or cut it off entirely. Also, keep in mind that this part of your car's charging system does have a limited lifespan. Automakers seem fond of saying it will last for the life of your vehicle, but plan on replacing it after approximately 70,000 miles.

What To Do When It Fails

Assuming that it's the alternator that is actually failing (as opposed to a broken or loose serpentine belt), it will need to be replaced. Few, if any, mechanics will try to repair one. When it's time to find a replacement, use one that is rebuilt. They work just as effectively as new units, will last as long, and cost at least 40% less. And thankfully, once it's replaced, it'll last for years.

About The Author

For all your used auto parts and used engines visit http://www.everdrive.com