Decimal Counter Plus Display with IC 4511 - IC 4029
If the display uses LEDs for the segments, resistors are required to limit the current through them to a safe level. If the display uses liquid crystal technology, these resistors are no longer necessary, since liquid crystal displays draw no current. However, if you build a project using a liquid crystal display, be sure to use a display driver that will deal with the special requirements of the liquid crystal display. The 4054, 4055, and 4056 are made for this purpose, while the 4511 is designed to drive LED displays. The newer 4543 is similar, and is designed for either LCD or LED displays. It can handle both common-cathode and common-anode LEDs. [....]
