All About Alternators

If you drive a car, truck, or SUV, you probably have an idea of what a starter or alternator is. And if you find your vehicle suddenly unable to start one day, the starter is often the culprit, or your battery has died. It could even be your alternator. An alternator is an electrical generator used in a car or truck that converts mechanical to electrical energy using alternating current, which is where the name comes from. Alternators generate the electricity that is channeled into the vehicle’s battery, where it is stored while provides voltage to run the various electrical systems such as the starter, the lights, the heater, and the radio, to name a few.

For the most part, alternators are relatively lightweight and are constructed using an aluminum outer casing. This is important since the aluminum, along with the vents, dissipates the large amount of heat generated by producing the electrical power.

How Alternators Work

Alternators have advanced significantly in the last 50 or 60 years. Originally alternators, which were called generators, were used to create a current that was controlled by an external regulator. The invention of the built-in regulator in the 90s used the warning light to start the alternator and begin the charging process.

Alternators are typical near the engine and are driven by the crankshaft which converts the pistons’ movement into circular movement. Most alternators are mounted using brackets that bolt to a specific point on the engine. One of the brackets is usually fixed into place while the other is adjustable to loosen or tighten the drive belt.

All cars, except for some electric and hybrid cars use an alternator. 

Alternator Components

  • Regulator - The voltage regulator controls the amount of power distributed from the alternator to the battery to control the charging process.
  • The Pulley - is connected to the rotor shaft and the drive belt system. Rotation created by the engine the drive belt system turns the pulley beginning the charging process.
  • Rectifier - is used to convert the alternating current (AC) to direct current (DC) during the charging process.
  • The Rotor - is the spinning, electromagnet component inside the alternator that rotates by the pulley and drive belt system.
  • Slip Rings - are used as a means of pushing the power to the rotor.
  • Drive End Bearing - The bearings support the rotation of the rotor shaft.

Fixing A Vehicle’s Alternator 

In most cars and trucks, an alternator can last for up to 10-15 years without any repairs. If an alternator fails, the vehicle might still run for a short time on battery power, but eventually the engine will stall as the battery charge is depleted. Replacing an alternator with a new part is expensive, but there are alternatives. 

At Brian Roberts Auto Electric Ltd. we repair and rebuild alternators based on the Original Equipment Manufacturer (OEM) specifications. Each rebuilt alternator is tested to ensure it meets our quality guidelines before it is ready for sale. With our rigorous standards, we give you peace of mind that your car or truck will run smoothly.