To get that power, did they have to use a rotary convertor from 60Hz 3-phase to get 400Hz?
https://en.wikipedia.org/wiki/Rotary_converter =] -- Anders Nelson +1 (517) 775-6129 www.erogear.com On Thu, Jul 26, 2018 at 10:49 AM Paul Koning via cctalk < [email protected]> wrote: > > > > On Jul 26, 2018, at 9:55 AM, W2HX via cctalk <[email protected]> > wrote: > > > > That is not the whole story of 400Hz. The other part of that story is > that now, all of the downstream equipment that uses the 400 Hz can have > much simpler AC to DC power supplies in them. At 400 Hz it is much easier > to regulate and filter out ripple. So instead of every piece of equipment > each having lots of large capacitors, now they only need small capacitors. > Space is at a premium as well as weight on a plane. > > This even applies to some terrestrial equipment. CDC used 400 Hz 3-phase > power for the 6000 series mainframes. 3-phase power cuts the ripple by a > large fraction and raises the ripple frequency 3x; 400 Hz instead of 60 or > 50 raises the ripple frequency further by that ratio. So high power > supplies get much smaller, both in the transformers and in the filter > capacitors. > > The 400 Hz came from motor-generators. Those also clean up the power a > lot, because any spikes or brief dips are absorbed by the mechanical > intertia and don't appear on the output. > > paul > > >
