Auto-transformers provide power to which indicator?

Auto-transformers provide power to which indicator?

• A. the stabilator position indicator
• B. the cockpit lighting
• C. the navigation computer
• D. the engine fuel controller

Answer: (A)

Auto-transformers are used to power certain cockpit indicators with the appropriate, small amount of voltage from the main AC electrical system. They step the voltage down to what the indicator requires and provide a stable source for gauge operation without drawing heavy current. The stabilator position indicator is one of those indicators that relies on an auto-transformer to receive its power, so it can reliably show the stabilator angle. The other items—cockpit lighting, the navigation computer, and the engine fuel controller—are powered from different parts of the aircraft’s electrical system (lighting circuits, avionics power buses, and engine-control power), not from the auto-transformer feeding the stabilator indicator. That’s why the stabilator position indicator is the best fit for auto-transformer power.

Auto-transformers are used to power certain cockpit indicators with the appropriate, small amount of voltage from the main AC electrical system. They step the voltage down to what the indicator requires and provide a stable source for gauge operation without drawing heavy current. The stabilator position indicator is one of those indicators that relies on an auto-transformer to receive its power, so it can reliably show the stabilator angle.

The other items—cockpit lighting, the navigation computer, and the engine fuel controller—are powered from different parts of the aircraft’s electrical system (lighting circuits, avionics power buses, and engine-control power), not from the auto-transformer feeding the stabilator indicator. That’s why the stabilator position indicator is the best fit for auto-transformer power.