Originally Posted by
Airbubba
Same here, both notebook computer and phone chargers work fine on 400 Hz.
Or, so I'm told...
I'm not rightly sure that's how it works with a modern switching power supply. You are saying that a 400 Hz input to a power supply that works on 50Hz somehow delivers more energy? Your slab argument may work for cold fusion or frogs and lily pads but I don't think it is applicable in this case.
And you claim that a little 100 watt computer brick can somehow overload a ground power CB on an airliner?
A 757 has a 90 KVA ground power connection, right?
The garden slab analogy is actually quite good, unfortuanatly it was used opposite of the actual situation:
The 400Hz corresponds to the supply frequency, not the rated input frequency of the device.
It nicely illustrates how a higher input (supply) frequency reduces the needed size of input filter capacitor.
Old (heavy) linear supplies that have a stepdown transformer at the input will probably work at 400Hz, but depending on the core material might run a bit warmer due to increased hysteresis losses.
What will most definitely not work on 400 Hz if designed for 50/60 is anything that uses the frequency to control something, one example is a synchronous motor. For those 50/60 will make a difference, in some cases does not matte much, fan speed, in others a lot; record player or electric clock.
Interesting question pon power factor correction in larger supplies, although almost all are active not just magnetic filters.