A lighting device (100), including a voltage source (110); a light engine (160) including one or more lighting elements (320) between a first power line and a second power line; a current detector (120) between the voltage source (110) and the light engine (160); a switch box (150) between the voltage source (110) and the light engine (160), connected to the electrical power, to ground, to the first power line, and to the second power line, and configured to switch the light engine (160) between a first configuration in which the first power line is connected to the electrical power and the second power line is connected to ground, and a second configuration in which the second power line is connected to the electrical power and the first power line is connected to ground; a lighting controller (130) configured to generate the switch control signal based on the detected current passing between the voltage source (110) and the light engine (160).