4 DC Generators
Direct current (DC) generators are machines that convert mechanical energy to electrical energy. This conversion of energy is based on the principle of the production of dynamically induced electromotive force (emf). In a DC generator the field is on the stator, whereas the armature is on the rotor. The field coil is excited by a DC supply. The rotor is rotated with the help of a prime mover, thereby cutting the flux produced by the field coils. The armature cuts the rotor flux and an alternating emf is induced in it, which is converted into a unidirectional emf with the help of the commutator. The basics of DC machines have been introduced in Chapter 3. This chapter introduces other aspects of the DC generators.