GB718535A - Improvements in colour lighting control systems - Google Patents

Abstract

718,535. Lighting supply systems. WILLIAMS, R. G. March 12, 1952 [March 13, 1951], No. 6367/52. Class 38(4) In a colour lighting system in which a selected hue is obtained by combining light from a number of different electric lamps of different colours and by controlling the relative degrees of energization of the different lamps, the necessity for dimmers to control the relative energizations is avoided by utilizing the electrical resistance of one lamp, such as one of a colour not required in the production of the selected hue, to control the voltage applied to another lamp. In one arrangement, Fig. 3, permitting of the production of thirty-eight different hues from three different coloured light sources R, G, B and two white sources W, the sources are controlled by two-way micro-switches 30 . . . 37 whereby. any source may be isolated from the mains L, connected directly across the mains, or connected in series with another source (or two or more sources in parallel) across the mains. Further control is afforded by micro-switches 38, 39 which allow series or parallel connection of the two white sources. The several micro-switches may be operated by a corresponding number of cams having a common control shaft which provides for the complete cycle of hues in one revolution. A greater range of hues may be obtained if further switches are provided which allow one or both of the lamps of each source to be energized at full brilliance, or the two lamps to be energized in series with each other. The switches' may be accommodated in the standard of a table lamp, or a casing forming a support for a spotlight.