What is an LED Driver and How Does it Work?

LED technology has come a long way since one of the first light-emitting diodes was invented by Texas Instruments in 1961. Back then, Robert Biard and Gary Pittman’s infra-red (IR) model was “microscopic”, according to TCP, making this early LED impractical for everyday use. However, in spite of its size, the invention of the first infra-red LED was a breakthrough in electroluminescence because it demonstrated that diodes and semiconductor materials could be used to create energy-efficient lighting for commercial and residential use.

LEDs have many technical components that make them effective energy savers, but one of the most important pieces of an LED is the driver. For those unfamiliar with light-emitting diode technology, this component can often get overlooked when upgrading to an energy efficient lighting solution. Read on to find out how this small component can have a huge impact on large-scale lighting. 

What is an LED Driver?

An LED driver is an external device that drives an electrical current or voltage to a single lamp or an array of LEDs. All LEDs require the use of a driver to manage energy, and a key component to understanding LED drivers requires understanding the different driver types and how they regulate energy in LED lighting systems.

One iteration of the LED driver is called an internal driver. Internal drivers often appear in conventional LED lamps for residential use. Unlike external drivers used in commercial LED lighting systems, internal drivers are contained within the lamp and convert the power source from AC (alternating current) into DC (direct current), protecting LEDs from power surges. This also makes it possible to easily replace LED lamps when they reach the end of their lifecycle.

While internal drivers make it possible to easily swap out lamps in a residential fixture or the type of overhead LED fixture you might find in an office or retail space, separate or external drivers simplify the process for maintaining LEDs used for street lights, commercial exterior lighting, and large-scale facilities like warehouses when the energy output is much more substantial. External drivers are divided into two main types: constant-current drivers and constant-voltage drivers, and each type is designed to operate LEDs with a different set of electrical requirements.

Constant-Voltage LED Drivers

Constant-voltage drivers power LEDs that require a fixed output voltage with a maximum output current. In these LEDs, the current is already regulated, either by resistors or an internal constant-current driver, within the LED module. These LEDs require one stable voltage, usually 12V DC or 24V DC. 

Constant-Current LED Drivers

A constant-current driver is used to regulate the amount of current that is supplied to an LED or LED array to maximize LED lifespan. Constant-current drivers power LEDs that require a fixed output current and a range of output voltages. There will be only one output current specified, labeled in amps or milliamps, along with a range of voltages that will vary depending on the load (wattage) of the LED. 

How Does an LED Driver Work?

Understanding LED drivers and picking the most effective energy regulating system for a large-scale lighting solution boils down to understanding how drivers actually work. In the simplest terms, drivers perform a very similar function to ballasts in that they convert raw power into the form used by the respective lighting system. In fluorescent lamps for example, the ballast converts energy into an arc between the two electrodes, reducing voltage and creating a consistent stream of light.

Similarly, LED drivers work by providing LED lamps or diodes with the electricity they require to function and perform at their best. Unlike most lamps that operate on a higher voltage alternating current, LEDs run on low voltage direct current. Because of this, LEDs need drivers to convert that alternating current to direct current and to keep the voltage flowing through an LED circuit at the rated level that the LED requires.

Finding the Right LED Driver for the Job

How to use an LED driver is largely dependent on the circuit specs of the lighting system it is meant to light as well as the amount of energy it needs to produce. Higher drive currents will result in more light from the LED, and will also require more wattage to run the light. It is important to know your LED’s specs including the recommended drive currents and heat requirements so you don’t burn the LED out with too much current or excess heat. 

It’s also important to consider whether you want your LED lighting system to be dimmable; for example with parking garage lighting where the lights may be controlled by occupancy sensors.  In that case you would need to choose an LED driver with dimming capabilities.

It is also important to consider the maintenance aspect of an LED driver. When an LED that requires a separate driver stops working before the end of its rated lifetime, it can usually be saved if the driver is replaced. Replacing a driver can prevent unnecessary costs of replacing a full LED system, and is a relatively inexpensive way to maintain the life and optimal function of the LEDs for a longer time. 

Understanding LED drivers is complex but critical for making informed decisions about commercial lighting. To find out more about upgrading commercial space to LEDs or to further the conversation about lighting best practices, see our FAQs and then reach out to one of the knowledgeable lighting experts at Imperial Lighting today.