Manual flashing operation for traffic signals - uses normally closed switch connecting supply to lamp and normally open switch connecting bimetallic strip flasher in series with lamp

摘要

Traffic lights may be made to flash while an operating button is held down. Otherwise they give a steady light output. The signal lamps are supplied via a fuse, a lamp selector switch, and normally closed contacts giving direct connection of the supply to the lamp, or normally open contacts which feed the lamp through a bimetallic strip flasher unit. Both normally open and normally closed contacts are operated from a single pushbutton which is spring loaded to the steady illumination position. When the pushbutton is operated the flasher unit is connected in circuit, and is removed from circuit when the pushbutton is released. The flasher unit may alternatively supply the coil of a relay which switches the current to the lamp.