Plugging laptop into 747 airframe power
I'm not talking about those new seat-side 12-16 VDC adapters in business and first class. On the upper deck of a United trans-Pacific 747 flight, I observed a passenger plug a laptop computer AC adapter into an airframe socket near the floor next to the left-side exit door. (You have to lift up the cover to get to it.) I think the socket said 110 volts and 400 Hz. While these computer adapters can go from 100-240 volts, all the ones I have seen are rated for 50-60 Hz. Made me wonder because capacitive reactance goes down at higher frequencies, and inductive reactance goes up -- but, I don't know what all goes on in those adapters. Thought it might be a possible safety issue but the passenger and flight attendant did not seem too concerned.