The entrance is generally dark, and in geomantic omen, we all call people to have an ever-burning lamp in the entrance. This ever-burning lamp is not really on for 24 hours. As long as it's open at night, it's no problem.
You want to install the big dipper lamp, which is your own hobby. You can install it. But from an economic point of view, as long as you install an energy-saving lamp, you can achieve the desired effect of Feng Shui, and you don't have to use the Big Dipper lamp. Do it yourself