A star for Christmas

by D Folger The time of the year has arrived again (doesn"t it come quicker and quicker?) when most of us are frantically racking our brains trying to decide on suitable presents. If you are in that position, this little Christmas Star may solve one of your problems. It is not a complicated circuit, as its appearance is obviously of far greater im- portance than its technical ingenuity. 60 9V IC1 N1 ... N6 = IC1 = 40106 It sometimes appears as if there are light- emitting diodes all around us, and certainly they have gradually replaced filament bulbs and neon lamps in all sorts of applications. Since these tiny components are now available in five different colours (red; amber; yellow; green; and blue), they are eminently suitable for use in ornamental lighting. When LEDs are arranged to light in flashe, rather than constantly, they can be made into very attractive, eye-catching ornaments. The circuit consists essentially of six relax- ation oscillators as shown in Fig. 1. Because...