universal LED display

10-02 — elektor october 1981 universal LED display Although a description of the circuit was published last month, it requires minor modifications for the printed circuit board described in this article. A LED level display using the well known UAA 170 has far more appli- cations than the thermometer and baro- meter referred to in the previous article. In many instances, an indication of a level is preferable to an exact and precise reading. With a display of 16 LEDs, the circuit now provides an easily read indicator that will prove excellent for a great many purposes. The 3 ICs, the LEDs and a few other components are all mounted on a printed circuit board that measures just 37 x 82 mm, small enough to be used practically any- where. When a certain voltage is to be measured with a meter, one of two extreme cases can occur: 1. The voltage may be too high for the range of the meter. A voltage divider consisting of two resistors will remedy the situation. 2. The voltage is too low...