Originally Posted by
Takiteasy
Am fairly sure I have seen the same by row 62 on 747s also with covers (or in that case a little flap) left open. I knew it was 110v so was tempted to recharge my devices but did not know about the 400Hz. What’s the rationale for that frequency do you know? Wouldn’t it be easier to use a frequency any appliance can be plugged on?
They use 400Hz as the transformers/motors needed to generate power at this frequency are smaller/lighter than those needed to generate electricity at 50Hz. Of course, smaller/lighter is better on planes!
For reference, the reason they don’t use 400Hz on the ground is because higher frequencies generate more losses when transmitted long distances via power lines; such losses are less relevant within the short confines of a plane fuselage!