Indoor hydroponic digital grow light ballasts are a superior way of driving an HPS (High Pressure Sodium) or an MH (Metal Halide) HPS-Conversion Lamp than with a traditional magnetic ballast. They convert mains electricity into the correct voltage to Start (fire-up) and then drive HID (High Intensity Discharge) grow lamps. Make sure you always match the wattage of the ballast to the wattage of the lamp. Digital grow light ballasts are very efficient but they can still run warm, so make sure they are mounted on a hard flat surface (not carpet) and keep combustible materials away from them.
