drinks round indicator

drinks round indicator elektor december 1980 — 12-19 H.-J. Urban Figure 1 gives a general idea of what the rounds indicator looks like. Nine LEDs are evenly spaced around the can"s circumference, one for each drinker. The indicator operates rather like an electronic version of Russian roulette, except that instead of risking a bullet through your head you risk being carried home with an empty pocket, but full of beer. Once the start button has been de- pressed all the LEDs will light up faintly. When the pushbutton is re- leased, all but one will go out. The first victim will be indicated by the remain- ing LED shining brightly in the dimness of the bar. Which LED this is depends entirely on chance as a form of random generator has been incorporated. The circuit operates as follows. First the on/off switch, S2, must be closed. The oscillator constructed around gates N1 ... N3 will then generate a series of pulses which are fed to the clock input of the 4017 counter, IC2. When sw...