More than 200 years ago, Henry Joseph Round observed that carborundum (SiC) crystals emitted a visible yellowish light when a potential of 10V was applied. He also observed that different crystals would emit green, orange, or blue light. In a letter to the editor of The Electrical World’s February 9, 1907 edition, he requested that any other person investigating this phenomenon contact him. That was unlikely to happen because Round was the first person to document this “ curious phenomenon” as he called it. His discovery of electroluminescence paved the way for today’s LEDs.
However, the first LEDs had low luminous efficacies, and as such, they were only useful as control lamps. They also tended to flicker if not supplied with a constant energy source. The development of LED drivers to convert mains voltages to match the load requirements for luminaires, meant greater stability, which coupled with increased efficiency and durability, make today’s LEDs real contenders in any lighting application.
At GRE Alpha, we take great pride in developing and manufacturing the best quality LED drivers. LED driver selection can be confusing to even the most experienced lighting system designer. The steps below should help guide you in selecting the most appropriate LED driver for your application.
- Determine if your application needs a constant voltage or constant current driver. A CV driver supplies a fixed voltage and is suitable for lighting applications where the number of LED strings and current draw are unknown. In these applications, current control is accomplished by additional components at the LED itself. CC drivers supply a fixed current and are suitable for applications that require constant current directly connected to the LED. This type of driver operates within limited voltage ranges, and it is therefore essential to choose a driver with an appropriate voltage rating.
- Determine your application’s output current (mA) requirements. When using a CC LED driver, note the current requirements of your luminaires. The CC driver should reflect that value output. The data sheets for luminaires state the requirements, with the value given in amps (A) or milliamps (mA). Some variable and selectable output current drivers offer a working current range or stepped values. Your luminaires must conform to the chosen values. Lower currents can extend the lifespan of your luminaires.
- Determine your application’s voltage (V) output needs. CV drivers require the same output as the voltage requirements of the luminaires. For multiple luminaires, each LED voltage requirement is added together for a total value. For CC drivers, the output voltage must be greater than the requirements of the luminaires.
- Determine voltage drop. Voltage drop is the amount of voltage loss in a circuit as a result of impedance. Any component that carries current is subject to resistance or impedance to current flow. Because LEDs need very low voltages to function, any loss in voltage can alter the color or brightness of illumination and can also cause the LED to flicker.
- Determine your input voltage (12V or 24V).
- Determine your wire run length.
- Determine the material of wire (assume copper in most cases).
- Determine the proper wire gauge against resistance (AWG value).
Our voltage drop calculator can assist you in selecting the right product for your application.
- Determine the necessary ingress protection (IP) rating for your application. If you have an outdoor application, it is crucial to consider IP rating. If your driver is going to be in contact with water, you may decide on an IP65-rated driver. Devices with a rating of IP67 can withstand in even harsher Products with this rating are protected from dust and can withstand water submergence to 1m for up to 30 minutes. Your selection depends on your application’s environment.
- Determine your form factor requirement. Ultra-slim LED drivers can save space and thus money. LED drivers that conform to standardized form factors allow for independent interchangeability of different drivers and modules.
- Determine your application’s termination method. In other words, how will you connect the LED driver to the application? While some LED drivers have built-in wiring leads, others do not, which may require you to purchase wires separately.
- Determine if you need a dimmable or non-dimmable driver. Not every LED driver on the market today supports dimming. Moreover, even if they do, many don’t guarantee flicker-free dimming. GRE Alpha has CC and CV LED drivers for flicker-free dimming applications. GRE Alpha offers LED drivers and dimming modules that are compatible with TRIAC, DALI, DMX, and EnOcean protocols just to name a few.
GRE Alpha® Electronics, Ltd. specializes in the design and manufacture of solid-state lighting power supplies and lighting control accessories which are the lifeblood of indoor and outdoor LED lighting systems. Please visit our website www.GREAlpha.com to learn more about our great selection of drivers.
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