Ballasts for electrical lighting fittings; electronic ballasts for operating discharge lamps; lighting ballasts; apparatus for controlling lighting; apparatus for lighting control; ballasts for electrical lighting fittings; computer controllers for operating lighting apparatus; computer controls for lighting apparatus; control consoles for lighting; dimming apparatus for electric lighting; electrical control units for lighting installations; electrical starting apparatus for discharge lighting; electrical starting devices for discharge lighting; electrical transformers for use with lighting; lighting ballasts; lighting control apparatus