[Milsurplus] 400 cycle 3 phase and WW2

[Mike Hanz]

My Navy Airborne Electrical Maintenance Notes pub dated September 1945 
shows no polyphase generators or inverters in the Navy inventory as of 
that date.  I know that I have a couple of 3kVA 28vdc rotary inverters 
that are dated in the 1950s that are three phase, so the shift must have 
occurred after the end of 1945.  The 800-1 rotary inverter and NE-1 
through -5 series of engine driven alternators that are in the AEMN are 
all single phase output.  I don't have a similar list of the USAAF 
engine driven generators, but the mainstay of the countermeasures work 
was an MG-149 inverter that is single phase output.  Individual systems 
like the APQ-13 had their own rotary inverters that were rapidly 
increasing in size, but to my recollection they were all single phase 
until after the war as well.  It certainly makes sense to go to three 
phase as time went by and the aircraft loads increased at a rapid rate.

  - Mike

On 1/12/2011 1:46 PM, Ray Fantini wrote:
> Thought all the old WW2 stuff ran from 28 volts DC and the B-36 was the first aircraft to exclusively use 115 volt 400 cycles 3 phase AC distribution? Being that AC distribution reduced design weight by several thousand pounds on a large aircraft. Recall reading something along this line in "Magnesium Overcast" by Dennis Jenkins. Maybe there was some application of 400 cycle AC prior to the B-36 but don't know what it would be. Did the old GO and GP transmitter have engine driven generators or motor generators  to develop their voltages from the ships DC distribution?