ADF power sources include which of the following?

ADF power sources include which of the following?

• A. 26 VDC synchro voltage, 28 VDC, and 115 VAC
• B. 12 VDC only
• C. 24 VDC and 240 VAC
• D. 5 VDC and 12 VDC

Answer: (A)

The main idea is that an ADF is powered from three separate supplies: a 26 VDC synchro voltage, a 28 VDC main DC supply, and 115 VAC for the AC portion of the system. This combination lets the ADF operate from common aircraft electrical buses and provides the necessary redundancy. The other options don’t fit because they omit one or more of these rails or propose voltages not used together for the ADF, such as relying on a single source or using voltages like 12 VDC, 24 VDC with 240 VAC, or 5 VDC that aren’t part of the standard ADF power setup.

The main idea is that an ADF is powered from three separate supplies: a 26 VDC synchro voltage, a 28 VDC main DC supply, and 115 VAC for the AC portion of the system. This combination lets the ADF operate from common aircraft electrical buses and provides the necessary redundancy. The other options don’t fit because they omit one or more of these rails or propose voltages not used together for the ADF, such as relying on a single source or using voltages like 12 VDC, 24 VDC with 240 VAC, or 5 VDC that aren’t part of the standard ADF power setup.