Traffic Light Control Circuit (20 Output Sequencing Circuit)
This page features a circuit that has twenty open collector outputs that turn on one at a time in a continuous sequential manner. The circuit make use of the 74LSxx family of TTL integrated logic devices. The circuits are designed to drive light emitting diodes or low current, low voltage incandescent lights but can also drive other loads of up to 80 milliamps. As logic circuits go, the 20 Step circuit is fairly simple but due to the high speed nature of the TTL Logic devices used, care must be taken when wiring these circuits. Simply put; The neater the wiring the better. If you would like to make use of these circuits, please take the time to find and read at least the first 2 pages of the manufactures data sheets for the integrated circuits. Using Google, search for "74ls(part number)" in the first box and "PDF" in the second box on the advanced seach page. A printed circuit board is available for this circuit. 20 Output Sequencing Circuit The follo...