Best mailing list ever. Thanks for the detail! =] -- Anders Nelson
+1 (517) 775-6129 www.erogear.com On Thu, Jul 26, 2018 at 11:14 AM Chuck Guzis via cctalk < [email protected]> wrote: > On 07/26/2018 07:54 AM, Anders Nelson via cctalk wrote: > > 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 > > As Paul mentioned, less a "rotary converter" than a AC motor-AC > generator hookup. One advantage is that the rotational inertia in such > a setup does have the ability to smooth over small power disruptions. > > Such MG setups were very common in industry before modern > semiconductors. When I had a summer job showing movies at a drive-in > theater (a long time ago), the supply for the carbon-arc lamps was a > 40hp motor powered by 3-phase 60Hz, driving a DC generator. In WWII > radio equipment, MGs in a unitzed form called "dynamotors" were used to > supply the high-voltage anode voltage for the tubes. Electroplating > shops similarly used large DC generator setups to supply plating current. > > 3 phase full-wave rectified AC has approximately 87% DC content at 6x > the supply frequency. So for 400Hz, the ripple is only 13 percent at > 2400 Hz before filtering. > > --Chuck > >
