(2) Mechanical energy into electrical energy Explanation: A dynamo is a device for converting mechanical energy into electrical energy, esp. one that produces direct current. A dynamo is an electrical generator that produces direct current with the use of a commutator. Dynamos were the first electrical generators capable of delivering power for industry, and the foundation upon which many other later electricpower conversion devices were based, including the electric motor, the alternating-current alternator, and the rotary converter.