FAA Powerplant Written Practice Test

Which components are included in a turbine engine exciter unit?

1. One storage capacitor and one transformer

2. Two transformers and two storage capacitors

3. Three transformers and one storage capacitor

4. Two storage capacitors and one generator

The correct answer is: Two transformers and two storage capacitors

The exciter unit in a turbine engine is responsible for providing the necessary electrical energy to the ignition system of the engine. The configuration of the exciter unit typically includes multiple components that work together efficiently to generate high-voltage pulses needed to ignite the fuel-air mixture in the combustion chamber. The correct configuration of an exciter unit includes two transformers and two storage capacitors. Transformers are essential in stepping up the voltage to the levels required for ignition, while storage capacitors are used to store this energy until it is needed for ignition. The two transformers facilitate redundancy and enhanced reliability in the ignition process, ensuring that if one transformer fails, the other can still provide the necessary voltage. The presence of two storage capacitors also means that there is additional capacity to store energy, which further supports reliable ignition under various operational conditions. This configuration ensures that the exciter unit can deliver sufficient voltage to generate a spark reliably, which is crucial for the successful operation of a turbine engine, especially during starting and low-speed operations. The combination of transformers and storage capacitors in this arrangement maximizes both the output and reliability of the ignition system in the harsh environment of an engine.