Difference Between Dynamo and Alternator (With Table)

Electricity forms the most indispensable part of our life today. It provides us with lighting, entertainment, and a lot of things. It is impossible to imagine life without electricity. Earlier humans used batteries for electricity. But it was slowly found that batteries were not cost-effective or reliable. 

Main Differences Between Dynamo and Alternator

  1. The basic difference between Dynamo and Alternator is that Dynamo produces direct current which flows in one direction whereas Alternator produces an alternating current which changes its direction constantly.
  2. The magnetic field of the Dynamic is stationary whereas the magnetic field of the Alternator is rotating.
  3. The input supply taken by the Dynamo is through the rotor whereas the Alternator takes its input supply through the stator.
  4. The Dynamo has less energy efficiency when compared to the Alternator which has very high energy efficiency.
  5. The range of Rotations per Minute(RPM) of a Dynamo is less approximately <2000RPM whereas the RPM of Alternator will range from 6000RPM to 12,000RPM
  6. Dynamos have high maintenance costs whereas Alternator requires very little maintenance.
  7. The brushes of the Dynamo do not last long as split rings are used and get worn off quickly whereas the brushes of the Alternator last long as solid rings are used and do not get worn off easily.
  8. A Dynamo can be used to charge a dead battery whereas an Alternator cannot be used to charge a dead battery.


Dynamos and Alternators have been the primary methods by which electric power has been produced. Earlier in cars Dynamos were used but in modern vehicles, Alternators have been replaced.

Similarly, in the commercial power generation industry, there always existed a technical battle between Dynamos and Alternators which finally Alternators won. Even though Alternators have emerged as big winners, Dynamos are still in use in certain specific applications.


  1. https://link.springer.com/content/pdf/10.1007/978-1-349-06180-8_6.pdf
  2. https://link.springer.com/chapter/10.1007/978-1-349-03176-4_5