> The unit is powered by 26 volts, 400 Hz, a standard voltage for aviation.
Any idea as to the history as to why this is the case?
I assume higher voltage is useful for lower amps? But why 400 hz?
Seems odd to use such a high voltage if components such as this must have internal transformers?
For mains voltage we use 50-60 Hz because lower frequencies work better with very large AC generators in power plants and, and lower frequencies are more efficient to transmit long distances.
In aviation, that matters because weight matters.
The downside is iron losses become bigger (heat lost in transformers). In a plane that typically doesn't matter because you aren't worried about losing a couple of watts of electrical power.
In today's world, it is irrelevant because all voltage conversion is done solid state (which is easier from DC), and all motors (of new designs) are brushless and therefore prefer to run from DC.
https://en.wikipedia.org/wiki/CDC_6600?wprov=sfti1
CDC had a defense contract for early air data computers, used in the F-18. That business survives today as part of General Dynamics.