Dnia Wed, 13 Aug 2014 20:17:19 +0200, Piotr Wyderski napisał(a):
> Albo odpowiednio wolno. ;-) Wychodzi na to, że Jarek ma najwięcej racji,
> bardzo ciekawe zestawienie:
> https://en.wikipedia.org/wiki/Utility_frequency#Hist
ory
> Ale tego księżycowego 16,7Hz nie umiem przyjąć do wiadomości... ;-)

Poczatkowo chyba jak pisza - z powodu turbin wodnych.

Ale - z tego co czytam to pare kolei nadal uzywa ... a tu chyba jest
powod
https://en.wikipedia.org/wiki/15_kV_AC_railway_elect
rification

The 50 Hz (60 Hz in North America) AC grid was already established at
the beginning of the 20th century. Although series-wound motors can in
principle run on AC as well as DC (the reason they are also known as
universal motors) large series-wound traction motors had problems with
such high frequencies. High inductive reactance of the motor windings
caused commutator flashover problems and the non-laminated magnetic
pole-pieces originally designed for DC exhibited excessive eddy
current losses. Using a lower AC frequency alleviated both problems

J.