Colour wheel

12V 10 * see text N1...N4 = 1C2 = 4093 N5...N8 = 1C3 = 4030 N9...N 14 = 1C4 = 4050 N15...N20 = 105 = 4049 D1...D12 = LED* (b/ 14 14 16 R 7 4 CLK IC4 IC5 IC3 IC2 CS 100n 00 3 7.0 R1 C3 MON Coloured light effects enjoy a high popularity as ornaments, eye-charac- ters, etc., and the present circuit pro- ves how an apparently rotating colour effect may be obtained with a mere handful of commonly available components. The colour wheel is composed of twelve bicolour LEDs, arranged in a circular form. First, a set of four red LEDs lights, followed by a green set, and, finally, amber. The colours are arranged to move in a clockwise direction, and at a speed that gives viewers the illusion that the motion is smooth and continuous. The bicolour LEDs consist of anti- parallel connected green and red diodes in a single transparent case. When both light simultaneously, their composite colour, i.e. amber, is emitted. Which group of LEDs lights depends on the duty factor of the drive signal from...