LEDs are low-voltage light sources, requiring a constant DC voltage or current to operate optimally. Operating on a low-voltage DC power supply enables LEDs to be easily adapted to different power supplies, permits longer stand-by power, and increases safety. During operation, the light source must be protected from line-voltage fluctuations. Changes in voltage can produce a disproportional change in current, which in turn can cause light output to vary, as LED light output is proportional to current and is rated for a current range. If current exceeds recommendations, the LEDs can become brighter, but their light output can degrade at a faster rate due to higher temperatures within the device which leads to a shorter useful life. LEDs, therefore, require a device that can convert incoming AC power to the proper DC voltage, and regulate the current flowing through the LED during operation. The driver converts 120V (or other voltage) 60Hz AC power to low-voltage DC power required by the LEDs, and protects the LEDs from line-voltage fluctuations.