The design of the generator voltage regulator

For approximately 30 years, the aircraft industry has been regulating the output of d-c generators by a carbonpile regulator which employs an electromechanical principle to adjust the field part on d-c generators. The advent of transistors and related solid-state devices, with their attendant high-current capabilities, has made possible the design of a solid-state device equivalent to the carbon pile regulator. This new device offers a number of distinct advantages: 1. Lighter weight. 2. Smaller power dissipation. 3. Greater ruggedness, i.e., capability to withstand environmental conditions such as shock and vibration. 4. Yields equal, or better, regulating characteristics.