 Nonetheless, Quick-start ballasts are also used in domestic (residential) installations because of the desirable feature that a Quick-start ballast light turns on nearly immediately after power is applied (when a switch is turned on).Quick-start ballasts are used only on 240 V circuits and are designed for use with the older, less efficient T12 tubes.The semi-resonant start circuit was invented by Thorn Lighting for use with T12 fluorescent tubes.