Ammeter in both vanes, the vanes repel each other and the moving vane deflects against the restoring force provided by fine helical springs. The deflection of a moving iron meter is proportional to the square of the current. Consequently, such meters would normally have a non linear scale, but the iron parts are usually modified in shape to make the scale fairly linear over most of its range. Moving iron instruments indicate the RMS value of any AC waveform applied. Moving iron ammeters are commonly used to measure current in industrial frequency AC circuits. In a hot-wire ammeter, a current passes
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