It’s tiny, and it can be a bit hard to find, but the photo cell sensor plays an important part in regulating the brightness of the LEDs in your boards.

The sensor reads the amount of brightness, and will automatically adjust the board’s LEDs to accommodate dusk, nightfall, or cloudy days. When the sensor detects bright sunlight, it brightens the LEDs to counteract the sun’s glare. In darkness, it dims the lamps so driving into the light won’t blind motorists.

If the board is parked onsite in bad weather, the sensor can get clogged with mud or dust (or in one case, spiderwebs). Simply remember to occasionally check the cells and clean them (a q-tip works best) if necessary.

— Contributed by SolarTech Support Specialist John Stout