Understanding LEDs and How to Choose the Right One

 

What are LEDs?

LEDs, or Light Emitting Diodes (a diode is a device that only allows electricity to flow through it in one direction, which is why LEDs have a positive (+) side and a negative (-) side) are silicon wafers that emit photons (light) when an electrical current passes through it.

What is a Discrete LED?

Discrete LEDs provide only a light source and leave the details of configuration, mounting, polarity, and alignment to the end user.

What is a LED Light Module?

A LED light module is a single or multiple discrete LED(s) configured and mounted to a printed circuit board with polarity connections.  LEDdynamics designs and manufacturers LED light modules to help companies get access and easily use the latest LED technology.

What is a LED Light Engine?

A LED light engine is the same as a LED light module with the addition of LED driver electronics.  This allows the LED to connect directly to power.

How do LEDs compare to traditional lighting?

The most significant distinction between traditional lighting devices (an incandescent light bulb, fluorescent tube, neon fixture, etc.) and LEDs is that LEDs do not use heat or a gas to generate light. An LED is a ‘Solid State’ device that contains no fragile filament or glass tube, making it an extremely durable and reliable light source that can be used in ways never before possible.

Where are LEDs being used?

The most common uses of LEDs are in consumer electronics and other equipment as indicator lights (the green or red ‘power on’ lights on a VCR or computer monitor).

Only with the introduction of HB (High-Brightness) LEDs and HF (High-Flux) LEDs, have LEDs been considered a “useable light source” for flashlights, accent lighting, signage, general-illumination and other applications.

LEDs are used in applications where long life and reliability is required. Many have been illuminated for 25 years and continue to function. Because LED use much less current than other light sources and run on low voltage DC, they are naturally suited for many battery powered applications. In very cold temperatures, LEDs turn on instantly while some fluorescents would fail to light. LEDs also generate smaller amounts of heat than their incandescent (filament) counter parts.

How do I choose the right LED?

To choose the right LED for your product or application, you should have a general understanding and knowledge of the different types of LEDs, their typical applications, and their differences in electrical, physical, optical and thermal characteristics. There are many different types and brands of LEDs on the market today and finding the LED that best suits your particular project requirements is essential for achieving the maximum performance, longevity and overall success of your LED product or application.

The first consideration when choosing an LED is to determine if a particular wavelength or color is desired for the application. Determining a specific color range (wavelength) or temperature range (degrees kelvin) of light to be used will significantly narrow the range of available LEDs that are suitable, and that can be considered for the application.

Next, the type of available power and drivability of the LED needs to be determined. LEDs of different wavelength (color) and type have different power requirements, electrical characteristics and thermal management requirements. The type of available power is a major factor in determining the best LED or LED circuit configuration for the application. In higher voltage applications, it may be more suitable to use many smaller LEDs, in place of one or two larger LEDs, to reduce the amount of power and heat that needs to be regulated.

Refer to the LED manufacturers’ specification documentation for information on electrical, physical, optical and thermal characteristics in order to become familiar with the LEDs that are being considered for the application, or contact LEDdynamics support for more information on how to choose the right LED and driver for the job.