versatile counter circuit - upwards or downwards, for LED or LCD, for common-cathode or common-anode

versatile counter circuit elektor march 1985 Counter circuits have long been a tradition in Elektor. It started with one of the very first issues way back in 1975 and has continued ever since. In spite of this we still get regular requests for counters to do this and counters to do that. To satisfy all these, we have developed a counter circuit that can: â–  count upwards and downwards; â–  be used with a variety of displays: LED, LCD, FD, and others; â–  store the counter contents; â–  preset the counter position. versatile counter circuit upwards or downwards, for LED or LCD, for common- cathode or common-anode The circuit diagram in figure 1 shows nothing really surprising: decoder, IC1; counter, IC2; and seven-segment LD1. The surprises are contained within the ICs! IC2 is a synchronous BCD upwards and downwards counter whose content may be preset. The presetting function is asyn- chronous. BCD counter ICs generally contain four bistables and a number of gates with which the r...