"There are many ways to automatically control these lights. The gadget I was using (until I completed this project, that is) was a simple mechanical timer. This product allows you to set separate turn-on and turn-off times and those repeat every day. The disadvantage of this product is that, as the seasons change, you need to constantly adjust the turn-on and turn-off times. As illustrated in Figure 1, the variation over the year (in sunset time in this example) is very significant even at my Northern California latitude, with almost three hours difference between the earlier and latest sunset times!" |