What Is An LED Driver?

Due to increasing energy regulations, most people are familiar by now with the long life spans and energy savings associated with LEDs, or light-emitting diodes. However, many are not aware that these
innovative light sources require special devices called LED drivers to operate. LED drivers (also known as LED power supplies) are similar to ballasts for fluorescent lamps or transformers for lowvoltage bulbs: they provide LEDs with the electricity they require to function and perform at their best.

LEDs require drivers for two purposes:
1. LEDs are designed to run on low voltage (12-24V), direct current electricity. However, most places supply higher voltage (120-230V), alternating current electricity. An LED driver rectifies higher voltage, alternating current to low voltage, direct current.
2. LED drivers also protect LEDs from voltage or current fluctuations. A change in voltage could cause a change in the current being supplied to the LEDs. LED light output is proportional to its
current supply, and LEDs are rated to operate within a certain current range (measured in amps). Therefore, too much or too little current can cause light output to vary or degrade faster due to higher temperatures within the LED. In summary, LED drivers invert higher voltage, alternating current to low voltage, direct current. They also keep the voltage and current flowing through an LED circuit at its rated level.

Internal vs. External LED Drivers
For the aforementioned reasons, every LED light source requires a driver. However, some LEDs, particularly those designed for household use, contain internal drivers rather than separate, external drivers. Household bulbs usually include an internal driver because it makes replacing old incandescent or CFL bulbs easier. These include LED bulbs with standard screw-in or plug-in bases or those that specify a line-input voltage (120 or  230 Volts) on their label. LEDs that typically require an external driver include cove lights, downlights, and tape lights, as well as certain fixtures, panels, and outdoor-rated lights. These bulbs are often used for commercial, outdoor, or roadway lighting purposes. They typically require a separate driver because it’s simpler and cheaper to replace the driver than the LEDs. Therefore, these LEDs will come equipped with a separate driver. Some times, manufacturer datasheets will specify whether or not an LED requires a separate driver, along with the type of driver it requires if necessary.