Title: Principle of a Generator/Alternator
Description: Depending upon the year of the street rod and the engine being used, either a generator or alternator is used in the charging system. A generator or alternator is used to produce electrical energy for charging the battery. The generator or alternator uses three things to change mechanical energy to electrical energy. These include a magnetic field, a conductor or wire, and movement between the two. The movement of the wire must cut or move perpendicular to the magnetic lines of force to produce electricity. This principle is called electromagnetic induction. Electromagnetic induction means changing mechanical energy to electrical energy using magnets produced from electricity.
The illustration above shows the principle of electromagnetic induction. To begin, there are two poles, a North Pole and a South pole. These poles are magnetically created when wire is wound around a metal core. As shown, there is a North Pole on the left, and a South Pole on the right. When the switch is closed, the electricity from the battery causes a magnetic field to be created in the metal core, which is called an electromagnet. The magnetic lines of force flow from the North Pole to the South Pole.
Between the poles there is a wire rotating 360 degrees. When the wire moves across the top of the magnetic field at position A, it is moving in the same direction as the magnetic lines of force, from left to right. It is not cutting any magnetic lines of force. So at this point there is no voltage being produced. However, when the copper wire continues its rotation and moves downward toward position B, more and more lines of force are being cut. As it cuts more and more magnetic lines force, more voltage is being produced. At position B, maximum voltage is being produced. As the wire continues to rotate downward to position C, less and less lines of force are being cut. So at position C there is no voltage being produced. When the copper wire rotates upward on the left side to position D, it is now cutting maximum lines of force again, producing maximum voltage.
The rotating parts are called the armature. The stationary parts are called the stator. A real generator has an armature that has many copper wires rotating within a stator that has two sets of North and South Poles. An alternator has the poles rotating (armature) and the copper wires stationary (stator). The alternator actually has seven sets of North and South Poles as the armature, and three groups of stationary wires as the stator.
Relationship to Street Rods: All street rods use some type of charging system to change mechanical energy of the engine to electrical energy. The electrical energy is used to operate the vehicle electrical systems during normal driving conditions. Also, the battery is being charged during this time. Each time electrical energy is removed from the battery, the battery must be recharged. If it is not, the battery will eventually become discharged to a point at which the electrical circuits would not operate. The voltage produced, and therefore, the available current, can be increased by increasing any one of the three components mentioned earlier. If the magnetic field is increased, the voltage will also increase. If the amount of wire is increased, the voltage will also increase. If the speed of movement, or the speed of cutting the lines of force, is increased, the voltage will also increase.
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Description: Depending upon the year of the street rod and the engine being used, either a generator or alternator is used in the charging system. A generator or alternator is used to produce electrical energy for charging the battery. The generator or alternator uses three things to change mechanical energy to electrical energy. These include a magnetic field, a conductor or wire, and movement between the two. The movement of the wire must cut or move perpendicular to the magnetic lines of force to produce electricity. This principle is called electromagnetic induction. Electromagnetic induction means changing mechanical energy to electrical energy using magnets produced from electricity.
The illustration above shows the principle of electromagnetic induction. To begin, there are two poles, a North Pole and a South pole. These poles are magnetically created when wire is wound around a metal core. As shown, there is a North Pole on the left, and a South Pole on the right. When the switch is closed, the electricity from the battery causes a magnetic field to be created in the metal core, which is called an electromagnet. The magnetic lines of force flow from the North Pole to the South Pole.
Between the poles there is a wire rotating 360 degrees. When the wire moves across the top of the magnetic field at position A, it is moving in the same direction as the magnetic lines of force, from left to right. It is not cutting any magnetic lines of force. So at this point there is no voltage being produced. However, when the copper wire continues its rotation and moves downward toward position B, more and more lines of force are being cut. As it cuts more and more magnetic lines force, more voltage is being produced. At position B, maximum voltage is being produced. As the wire continues to rotate downward to position C, less and less lines of force are being cut. So at position C there is no voltage being produced. When the copper wire rotates upward on the left side to position D, it is now cutting maximum lines of force again, producing maximum voltage.
The rotating parts are called the armature. The stationary parts are called the stator. A real generator has an armature that has many copper wires rotating within a stator that has two sets of North and South Poles. An alternator has the poles rotating (armature) and the copper wires stationary (stator). The alternator actually has seven sets of North and South Poles as the armature, and three groups of stationary wires as the stator.
Relationship to Street Rods: All street rods use some type of charging system to change mechanical energy of the engine to electrical energy. The electrical energy is used to operate the vehicle electrical systems during normal driving conditions. Also, the battery is being charged during this time. Each time electrical energy is removed from the battery, the battery must be recharged. If it is not, the battery will eventually become discharged to a point at which the electrical circuits would not operate. The voltage produced, and therefore, the available current, can be increased by increasing any one of the three components mentioned earlier. If the magnetic field is increased, the voltage will also increase. If the amount of wire is increased, the voltage will also increase. If the speed of movement, or the speed of cutting the lines of force, is increased, the voltage will also increase.
Back to Electrical Principles