The purpose of the dynamo in cars is to generate Direct Current (DC) with the help of a commutator. Car dynamo uses rotating coils and magnetic fields to convert mechanical rotation into electric energy. It was the first of its own kind and is used as a preamble in many electric conversion devices invented later. The later inventions gradually replaced dynamo and now it is rarely used in vehicles. In this guide, we have discussed car dynamo in detail.
Working Principle of Car Dynamo
The car dynamo works on the principle of electromagnetic induction. According to this principle; current can be generated by spinning a coil or wire inside a magnetic field or vice versa. The spinning creates potential difference in a coil and forces current to flow from it. A car battery dynamo also uses this simple principle for working.
Car dynamo parts include: horseshoe magnets, two poles, two half-split rings, commutator, conductor loop and brushes.
The loop first rotates parallel to the magnet to generate voltage. It changes its direction from parallel to horizontal with the help of a commutator. When the loop rotates to the quarter of the magnetic field in a horizontal position, the current is generated which flows in the loop. This loop is connected to the external circuit by circular (split) rings to circulate current. The brush is a piece of conducting material that connects a ring and meter. It is used to reflect the amount of current being supplied to the vehicle.
Types of Car Dynamo
The dynamo was introduced to replace messy liquid batteries. The early version of the dynamo uses a large permanent stationary magnet and moving coil to generate current. The later versions were modified to meet the demand of increasing current generation.
Third-Brush Dynamo
The third-brush dynamo was used in the early vehicles as an electric generator. It consists of three brushes connected to different parts of the vehicle. The first brush is earthed with the vehicle body, the second with the battery terminal and the third to the field winding (coil). A switch is connected to the other end of the winding to control the amount of current supplied. This type was gradually replaced by the two-brush type because of the lower voltage regulation.
Two-Brush Dynamo
The two-brush dynamo replaces the weaknesses of the third-brush dynamo. It consists of two brushes, one is earthed with the battery and the second is connected with field winding (coil). This dynamo was replaced by the alternator, as it produces more current and has a longer life span.
Is Dynamo and Alternator the Same Thing?
Alternator and dynamo are two different electronic devices that are often confused with each other. Both the devices work on similar principles, but functionality is slightly different. In an alternator, the magnetic field rotates while the conductor is stationary. Whereas, in dynamo, the conductor rotates and the magnetic field remains stationary. Moreover, an alternator is used to generate Alternating Current (AC) and dynamo generates DC.
Application of Dynamo in Modern Cars
The application of dynamo was reduced in petrol and diesel engine vehicles. The technology used in dynamo was old and can not meet the increased electricity demand of these vehicles. However, with the initiation of electric vehicles usage of the dynamo is revived.
Dynamo in Electric Vehicles
Dynamos are capable of converting mechanical energy into electric energy by using electromagnetic induction. Therefore, they are placed on the tyres of electric cars to produce energy. They are used to maintain the efficiency of a car when the accelerator is not pressed like driving down a slope, or before pushing brakes. Each dynamo is placed at top of the tyre connected with a smaller gear placed on the rod. On the other end of the rod, there is another smaller gear connected with larger gear that produces RPM (Rotations Per Minute). When the accelerator is pressed that larger gear will rotate and generate RPM. Whereas, when the accelerator is not pressed the dynamo will provide energy (24 v each) and smaller gear will generate RPM. Dynamos are not only efficient for electric engines, it is also economical than other components used in electric cars.
Common Cause of Dynamo Failure
Wear-out commutator and carbon brushes is the common car dynamo problem. Brushes get worn out and become smaller in size which weakens the connection between spring (which holds brushes) and commutator. The lack of connection causes a spark also known as ‘Arching’. The continuous arching can melt the field winding and even lead to complete malfunction. In this situation, the battery is drained completely, as it has to supply more electricity. Generally, ignition switch and battery warning lights on car dashboard are symptoms of malfunctioning dynamo.
In recent times, car dynamos are used in electric vehicles as additional support. They are used to maintain the efficiency of electric cars when the accelerator is not pressed. If you want to experience this efficiency, browse through these used electric vehicles.
- Used Tesla Model X for sale in the UAE
- Second-hand BMW i3 for sale in the UAE
- Used Hyundai Kona for sale in the UAE
Stay tuned to UAE’s top auto blog for more information on car parts and their working.
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