A grid of two halves
Stories from Physics for 11-14 14-16
The eastern and western halves of the Japanese national grid run on different frequencies: 50 Hz and 60 Hz respectively. This difference arose as the first generators, functioning at 50 Hz, were imported to Japan from Germany and were installed in the east of the country. After the Second World War, 60 Hz generators were brought from the USA and installed in the western grid. Though it used to be the case that some electrical appliances could only be used on one grid, contemporary electronics are designed to work on both systems.