Which component is used to control the generator power in the T-6?

The generator control unit plays a crucial role in managing the electrical power produced by the generator in the T-6 aircraft. This component is responsible for regulating the generator's output by controlling the voltage and ensuring that it meets the demands of the aircraft's electrical system. It achieves this by monitoring system parameters and adjusting the generator's performance as needed to maintain stable and reliable power.

The generator control unit being the correct answer highlights its essential function in the overall electrical management of the aircraft, ensuring that components receive the appropriate power levels while safeguarding against potential overloads or faults in the system. Its ability to maintain proper voltage levels is vital during different flight operations and conditions, contributing directly to the safety and efficiency of the aircraft.

The other choices pertain to different functions within the aircraft's systems. For instance, the battery contactor is used to connect or disconnect the battery from the electrical system, while the auto-throttle system is designed to manage engine power settings automatically without being directly related to generator output. The voltage-regulating panel, although it is involved in managing electrical systems, does not directly control generator output in the way that the generator control unit does.