- The origins of 60-Hz as a power frequency (ieeexplore.ieee.org)
In 1891, Westinghouse engineers in Pittsburgh selected 60 Hz as their new power frequency. That same year, AEG engineers in Berlin selected 50 Hz as their new power frequency. Although much has happened since 1891, these two frequencies remain the principal power frequencies in use worldwide. Many people continue to be affected by the decisions on frequency standards made so very long ago. The author discusses the origins of 60 Hz as the power frequency now used in the USA. The author covers the work of Charles Scott, Benjamin Lamme and L.B. Stillwell of Westinghouse, the experimental period of 1821 to 1880, the light period from 1880 to 1890, the power and period of 1890 to 1925, and the period of systems interconnection from 1925 to 1990. Particular emphasis is given to the development of frequency for lighting systems and of frequency development in the USA, Europe and Japan.
- Broccoli (Wikipedia)
Broccoli (Brassica oleracea var. italica) is an edible green plant in the cabbage family (family Brassicaceae, genus Brassica) whose large flowering head, stalk and small associated leaves are eaten as a vegetable. Broccoli is classified in the Italica cultivar group of the species Brassica oleracea. Broccoli has large flower heads, usually dark green, arranged in a tree-like structure branching out from a thick stalk which is usually light green. The mass of flower heads is surrounded by leaves. Broccoli resembles cauliflower, which is a different but closely related cultivar group of the same Brassica species.
- Utility frequency (Wikipedia)
The utility frequency, (power) line frequency (American English) or mains frequency (British English) is the nominal frequency of the oscillations of alternating current (AC) in a wide area synchronous grid transmitted from a power station to the end-user. In large parts of the world this is 50 Hz, although in the Americas and parts of Asia it is typically 60 Hz. Current usage by country or region is given in the list of mains electricity by country.