What is a Transformer-Rectifier Unit (TRU) used for?

What is a Transformer-Rectifier Unit (TRU) used for?

• A. Converts AC power into DC power
• B. Converts DC power into AC power
• C. Stores electrical energy
• D. Conditions hydraulic fluid

Answer: (A)

A Transformer-Rectifier Unit turns AC power into DC power to feed the aircraft’s DC electrical system. It combines a transformer, which uses the AC supply from generators or the APU to isolate and step down voltage, with a rectifier that converts the alternating current into direct current. The resulting DC power, usually around 28 V, drives the DC buses and charges batteries as needed. The other functions—DC-to-AC conversion, energy storage, or hydraulic fluid conditioning—are handled by different equipment, so the TRU’s role is specifically AC-to-DC conversion for the DC electrical system.

A Transformer-Rectifier Unit turns AC power into DC power to feed the aircraft’s DC electrical system. It combines a transformer, which uses the AC supply from generators or the APU to isolate and step down voltage, with a rectifier that converts the alternating current into direct current. The resulting DC power, usually around 28 V, drives the DC buses and charges batteries as needed. The other functions—DC-to-AC conversion, energy storage, or hydraulic fluid conditioning—are handled by different equipment, so the TRU’s role is specifically AC-to-DC conversion for the DC electrical system.