Which device provides the primary source of DC power in the DC electrical system?

Which device provides the primary source of DC power in the DC electrical system?

• A. AC Generators
• B. APU Generator
• C. Batteries
• D. DC Converters

Answer: (D)

The essence is that the DC electrical system is powered by converting available AC power into DC. AC generators on the engines (and the APU) provide the initial energy, but they’re not used directly by the DC buses. Those AC outputs feed the DC converters (rectifier/regulator units), which convert and regulate that power to the 28 VDC the DC buses and loads require. Batteries play a vital backup role, supplying DC only when AC sources aren’t available or during start, but they aren’t the normal, primary source. So the DC converters are the key link that provides steady, usable DC power to the system during normal operation.

The essence is that the DC electrical system is powered by converting available AC power into DC. AC generators on the engines (and the APU) provide the initial energy, but they’re not used directly by the DC buses. Those AC outputs feed the DC converters (rectifier/regulator units), which convert and regulate that power to the 28 VDC the DC buses and loads require. Batteries play a vital backup role, supplying DC only when AC sources aren’t available or during start, but they aren’t the normal, primary source. So the DC converters are the key link that provides steady, usable DC power to the system during normal operation.