At OSRAM Opto Semiconductors, the name “Brilliant Mix” stands for a new, highly efficient concept for generating white light with a high color rendering index for general lighting applications with light-emitting diodes (LEDs).
This paper was prepared to provide a first look at the new concept and the way LED lighting works. In addition to comparing the standard white concepts, it includes two proposals for controlling Brilliant Mix applications.
In this presentation, OSRAM Opto Semiconductors’ High Color Rendering Index expert Marc Dyble examines:
• Light and Color: Understanding the Basics
• Color Rendering Index for White Light Sources
• Methods for Creating White Light with LEDs
• New Techniques for Achieving High CRI
The proper use of light is both a science and an art form, OSRAM Opto Semiconductors’ High Color Rendering Index expert Marc Dyble writes. Lighting can be mere illumination or can create an effect, but new LED technologies can help to make dull spaces come alive. Everyone’s color vision is different, therefore interpreting color can be very subjective, but specifications can provide a basis for objective comparison.
Defining LED Specifications
One major specification used in the lighting industry is the Color Rendering Index (CRI). “Color rendering” describes how an object appears to the human eye based upon an ideal or natural light source. An artist showing their paintings would most likely want their work lit so that rich, vibrant colors are noticed. A discussion using attributes of CRI can quickly get artist and gallery manager “on the same page” regarding lighting.
The turnkey reference design, based on high performance LEDs from Osram and highly integrated and advanced driver ICs from Marvell, drastically reduces the engineering complexity involved in designing and manufacturing premium performance, high- color rendering index (CRI) LED luminaries for professional and commercial lighting applications. This is expected to enable lighting original equipment manufacturers (OEMs) to easily develop and offer significantly higher quality LED products at more affordable prices to end users.
Warm white light with a high luminous efficacy (110 lm/W) and a color rendering index (CRI) of more than 90 are the result of the new “Brilliant-Mix” concept from OSRAM Opto Semiconductors. The intelligent color mix based on powerful OSLON SSL LEDs in EQ-White and Amber covers a broad white spectrum from 2700 to 4000 K. Depending on the required luminous flux, a different number of these LEDs can be combined to produce warm white feel-good light of high quality that will set new standards in general illumination applications.
‘Brilliant Mix’ refers to a light system containing a mix of high efficacious EQ white LEDs with amber red LEDs. ‘Brilliant Mix’ allows high efficacious white light sources with high CRI at low color temperatures. As red LED’s lumen output degrades faster with temperature than white LED’s, a Brilliant Mix system might require an active feed back system for color control. Such a system also provides brightness control. This application guide describes the design approach for a Brilliant Mix system including LED system parameters, heat sink, LED driver, light sensor and feed back loop to control the color temperature and brightness of the light source.
Multi color LED systems refer to light engines utilizing different color / white LEDs. As an example ‘Brilliant Mix’ contains a mix of high efficacious EQ white with amber red LEDs. It allows high efficacious white light sources with high CRI at small color temperatures. As red LEDs degrade faster with temperature than white LEDs, an active feedback system for color control might be required. The feedback system can also serve to stabilize the light engine’s brightness. This application guide describes the operation of light sensors including the achievable color control and the software routine to make the sensor work in conjunction with LED driver PWM control for EQW, amber and optional blue LEDs.
The Brilliant Mix LED color mixing concept from OSRAM Opto Semiconductors is now even easier to control thanks to the new Brilliant Mix Universal Controller from Elec-Con technology. The controller is available in a standard version – with or without a sensor – and in a customized version. It can be adapted to current building systems standards, such as DALI, KNX and EIB. The controller concept has been developed as part of the LED Light for you network.
The platform consists of a controller-board including the Brilliant-Mix-Firmware, a current-source with 4 driver-channels, a Light-Engine containing OSRAM Opto Semiconductors Brilliant-Mix-LED’s in four colors and can optionally be equipped with a True-Color-Sensor-Module. Using one controller, you can operate multiple current-sources, and with each current–source you can drive multiple Standard-Light-Engines or even a customized Light-engine made by Elec-Con especially for you. CCT and Dimming can be either adjusted by an On-Board-Trimmer, or by using dedicated universal analog or digital interfaces, which are implemented in the shape of an Extension-Port on the PCB of the controller.