B737 NG pressurisation mode controller

[Pin Head]

Is it AC or DC powered? The auto part is not battery backed up for sure.

[babisiliop]

In all modes uses DC

[IFixPlanes]

28V DC BUS 1 is the source for CPC 1
28V DC BUS 2 is the source for CPC 2
28V DC BAT BUS is the source for Control Panel and the OFV manual mode

[SkyWagon737]

System relies on DC power, auto controllers use DC power to move outflow valve, separate DC motor is provided MANUAL MODE.
And if you lose all AC power, and you can only use MANUAL MODE.