Electronic Tech

Some years ago a co-worker mentioned that his neighborhood was having an outdoor Christmas lighting contest. He was wondering about a “color organ” or something similar on his roof! What we came up with is a lighting control device using triacs with isolated inputs from a serial UART which was then fed from a computer's RS-232 serial port (remember those?!) I checked with my prototype supplier at the time to make the triac circuit boards. The design was not very complicated, consisting of square pads for the triac itself and smaller pads for a resistor and wiring connections. I asked for a bid for 8, 2 inch square, single -sided circuit boards with no connectors, holes, feed-thrus, plating, etc. His response was “Just exactly what do you want me to do to these boards?!” The UART portion was breadboarded (wire-wrap) and built inside a weatherproof box, with runners out to various locations on the roof. The software merely sent random patterns to the UART and displayed all kinds of run-ups, sliding dots, etc. on the strings of lights. Needless to say, he won, hands down, the neighborhood contest!

- Shared October 14, 2012