In aviation electrical terminology, how does an alternator differ from a generator?

In aviation electrical terminology, how does an alternator differ from a generator?

• A. An alternator produces DC directly; a generator produces AC that is rectified to DC.
• B. An alternator produces AC only and a generator produces DC only.
• C. Both produce DC directly.
• D. An alternator produces AC that is rectified to DC; a generator produces DC directly.

Answer: (D)

Think of the difference in terms of what each device puts out and what happens to that output. An alternator makes alternating current. That AC is then converted to direct current by a rectifier so the aircraft’s 28V DC electrical system can use it. A generator, as used in aviation historically, provides direct current directly, without needing a rectifier downstream. So the best description is that the alternator produces AC that is rectified to DC, while the generator produces DC directly.

Think of the difference in terms of what each device puts out and what happens to that output. An alternator makes alternating current. That AC is then converted to direct current by a rectifier so the aircraft’s 28V DC electrical system can use it. A generator, as used in aviation historically, provides direct current directly, without needing a rectifier downstream. So the best description is that the alternator produces AC that is rectified to DC, while the generator produces DC directly.