Ammeter to be measured with both polarities, common in scientific and industrial equipment. Zero-center ammeters are also commonly placed in series with a battery. In this application, the charging of the battery deflects the needle to one side of the scale (commonly, the right side) and the discharging of the battery deflects the needle to the other side. A special type of zero-center ammeter for testing high currents in cars and trucks has a pivoted bar magnet that moves the pointer, and a fixed bar magnet to keep the pointer centered with no current. The magnetic field around the wire carrying
Main Street Electrical Parade Street Electrical Parade was the Electrical Water Pageant, a show made up of fourteen 25-foot-tall (7.6 m) screens with electrical lights placed on them. Not long after the Electrical Water Pageant debuted, Card Walker commissioned the development of what became the Main Street Electrical Parade to provide Disneyland with a similar nighttime visual spectacle. The parade's design used nickel–cadmium batteries, which the Disney movie studio had recently started using, and Italian-made miniature bulbs that Disneyland staff had seen in light displays along Michigan Avenue in Chicago, Illinois. Disney arranged for the parade's original floats to be constructed by Silvestri, the