How Alternators Work

We find the alternator in the engine bay of a car and the shaft of an alternator is forced through a tape. Alternators produce AC (alternatinc current) and with AC, the current of electrons flow forwards and backwards constantly. You will find this in your home. Electrical components use DC or direct current, where the electrons flow in just one direction. The alternator converts the alternating current into a direct current through a recrtifier. The alternator uses the regulator. 

The engine combusts fuel. This is used to turn the crankshaft and propel the vehicle along. The engine only provides mechanical force, but doesn't produce electricity. Alternator also helps to power the vehicle. The Battery stores energy in a chemical manner, but it doesn't store electricity. When the car starts, battery provides the huge amount of current to starter motor, which turns the engine on. Once the engine is running, the alternator is used to recharge the battery to have enough stored energy to start the engine in the future. But if the battery is left to discharge, it won't be able to provide large current necessary to start the starter motor so then the car would have to be restarted. 

At the front of the alternator we have a pulley. This is a wheel with grooves cut into it to help grip the thing that provides a rotational force. The pulley wheel is attached to a shaft, and the internal components are help inside of the main housing that consists of the front and the rear bracket. The slots help air to pass through and remove the unwanted heat. 

There are many different design but there is a 3 wire design with an internal regulator and rectifier. The B terminal is the output of alternator which charges battery. The S terminal allows the regulator to sense the voltage. The F terminal provides the initial power to the electromagnet during the startup. Electricity flows through car frame to and from the battery negative terminal. We find the regulator and rectifier in the back of the unit. 

We find these components at the rear end of a unit. By removing the housing, we can see inside the unit. The first thing we see is the stator. There are laminated sheets and copper wire wound between slots. One end is wound between each other to form a neutral point. 

This is a star configuration. 

Each coil produces AC electricity, and the outer end attaches to the rectifier. The alternator produces AC but the battery need direct current, so the rectifier convert AC into DC electricity. 

The center of the alternator we find another wires wound around an iron core and connected to the shaft with slip rings. Then we find brushes inside which is pushed out with springs-loaded carbon blocks to form an electrical connection. The electricity is provided through the brushes. An electromagnetic fiend is created and 2 iron poles (north and south) are integrated with each other. 

When the engine turns the shaft, it rotates the electromagnet, which allows the stator coils to turn. The alternate produces 3 phase AC into DC. The faster the vehicle travels, the faster the crankshaft rotates, and so the faster the alternator also rotates. The diode trio converts the current from AC to DC. The current produced by the alternator will vary with the speed of the coil. 

The voltage and current produced by the alternator will vary with speed. Another componenet is used with speed called the regulator, varying the current of the electromagnet to control its strength. Magnetic field changes with a current and becomes stronger when the wire is wrapped into a coil.

Passing a magnet throguh a coil of wire can also generrate a current. Moving a magnet in and out repeatedly, the current will flow forwards and backwards, and this is how AC is generated. If we move the magnet faster, a stronger current is generated. If we use a stronger magnet, the current increases. Using a larger coil with  more turns will generate a larger turrent. With the electromagnet we can generate voltage and current to vary with the strength of the magnetic field.

With the magnet between and parallen the 2 coil nothing generates, but the coil willc cause more and more electrons to push forwards up until its maximum intensity in both directions. While plotting, we would get a sine wave with current flowing through positive and negative area. We can add coils to produce more phases and more power. Adding more coils would give more phases. The coil is at different angle and produces different intensities at different times. We can add coils for each of degrees to create a 3 phase where we will have phases flowing forward and backwards. 

The current can flow between coils as current of each changes direction. Now we are producing 3 phase electricity, but everything in a car uses DC. To convert from AC to DC, we will use a full bridge rectifier, 6 diodes in connected in parallel. 

Diodes allow current in one direction and they block the current in the other direction. 

For every turn of the magnet, current will only be available for about half of the turn, whereas the other half will be completely blocked. If we connect each of the 3 phases separately to a diode, then the current will be blocked at different times. Therefore, we can combine these phases into a block of diodes, and only certain phases will be allowed to pass through. To smooth ripple out, capacitor smooths and ejects electrons automatically to maintain a smoother output. 

If the car speeds up, then the magnet will spin faster. Using an electromagnet can increase and decrease strength/voltage by varying its voltage. The electromagnet is powered by a voltage regulator once the alternator is generating electricity. 

There is a transistor in the regulator, a type of electronic switch turned on and off thousands of times per second by a controller, controlling the amount of current flowing. We can control the transistor for a 50% duty cycle so that the current only flows around 50% of the time. So we can vary the open/close times of transistor switch to control current of electromagnet. 

Here's the final drawn diagram: