LEDs Require Drivers For Two Purposes

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 specialized 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 (120-277V), 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 convert 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.

Choosing an LED Driver

There are two main types of external LED drivers, constant-current and constant-voltage, as well as a third type of driver called an AC LED driver which will also be discussed. Each type of driver is designed to operate LEDs with a different set of electrical requirements. When replacing a driver, the old driver’s input/output requirements must be matched as closely as possible.