Engine Parts

Automotive alternators
Alternators are used in modern internal combustion engine vehicles to charge the battery and power the electrical system while the engine is running. Until the 1960s, cars used DC generators with commutators. With the availability of affordable silicon diode rectifiers, alternators are used.

Marine alternators
Marine alternators used on yachts are properly adapted to the seawater environment. They are designed to be explosion proof (ignition protected), so brush sparks cannot ignite explosive gas mixtures in the engine room environment. Depending on the type of system installed, they may be 12 or 24 volts. Larger marine diesels may have two or more alternators to handle the high power demands of modern yachts.

Diesel-electric locomotive alternator
In later diesel-electric locomotives and diesel-electric multiple units, the prime mover turns an alternator that supplies power to the traction motors (AC or DC). Traction alternators typically use integrated silicon diode rectifiers to provide up to 1200 volts DC to the traction motor. The first diesel-electric locomotives, many of which are still in use, used DC generators, before silicon power electronics made it easier to control the speed of DC traction motors. Most of these have two generators, one of which generates the field current for the larger main generator.

Radio alternator
Variable reluctance type high frequency alternators are commercially used for radio transmission in low frequency radio bands. They were used to transmit Morse code and were used experimentally to transmit sound and music. In an Alexandria alternator, both the field and armature windings are stationary and current is generated in the armature due to the changing reluctance of the rotor (which has no windings or current carrying parts). Such machines were used to generate radio frequency electrical current, albeit inefficiently, for radio transmission.