Types of Direct-Current Machines

Author: E.E. Kimberly

Direct current is produced commercially by application of the principle pertaining to generation of electromotive force that was discovered by Faraday and is described on pages 3 and 4. A machine that is used for production of direct current is called a direct-current generator or dynamo.

Direct-current motors, which utilize direct current to drive other machines, operate on the principle laid down by Lenz in his law of force on a conductor carrying current in a magnetic field, as described in Chapter 11. The direct-current motor and the direct-current generator are alike in construction and differ only slightly in their design proportions. The use of the direct-current machine as a generator will first be discussed, and then its use as a motor will be considered.