[time-nuts] The home time-lab

[jimlux]

On 7/25/16 6:55 AM, Bob Camp wrote:
> Hi
>
> If you go back far enough in time …. there is another alternative:
>
>        Big rectifier bank, turning AC into DC, often off of multiple phases or sources.
>
>        Big DC motor running into a fairly large flywheel.
>
>        AC generator (or in some cases DC generators) running off of the shaft
>
>        A tuning fork (yes state of the art timing) based control on the AC output frequency
>
>        A saturated reactor control loop on the generator side, same thing on the motor side.
>
> Wonderfull stuff. State of the art UPS for your shipboard computer in 1962. Ear muffs anyone?
>
> Bob

we had a system like this to turn 60 Hz into 50 Hz with a toothed belt 
drive between synchronous motor and synchronous generator.  It whined.. 
"Satan's Siren" is what we called it.

IBM mainframes used a similar scheme but I can't remember the details.