News

Since the first LED was invented over half a century ago, the evolution of LED lighting technology and proliferation of cost-effective LEDs set a new standard in homes and businesses alike, proving to be versatile, long-lasting, and highly efficient. Though it took several decades for LEDs to gain traction, once they did, technological advancements started coming at a fast and furious pace. In the last few years, tunable white lighting has entered the mainstream of LED design promising to change the world in a significant way.

What is Tunable White?

Tunable white, or Kelvin changing LED lighting, is a system that enables the color correlated temperature of lighting (CCT) to be adjusted in both intensity and color appearance with the intention of aligning with circadian rhythms or activities that require more physiological or psychological engagement. LED lighting mixes red, green, and blue channels to deliver a range of colors across the color spectrum that can simulate natural light.

With conventional tunable white products, there are two controllable phosphor-coated LEDs; one warm-white color (usually around 2700K) and a second cool-white color (usually 5000K to 6500K). There are also newer products that use three or more LED primaries which gives them the capability to produce a wider range of colors than simply different CCTs of white. The right color temperature and illumination achieved through tunable white lighting can make a real difference in visual perception by bringing the dynamics of natural light indoors.

Ushering in an Unprecedented Level of Comfort and Control

An article published by GRE Alpha in 2018 talks about the health benefits of tunable white lighting. While the information remains completely valid, more advanced control systems and higher output options are coming to market all the time bringing things to life that were formerly inconceivable. Now, with as much as 90% of our time spent indoors, the push by the lighting design community to more effectively leverage the power of tunable white lighting will only continue to surge.

Recently, supported by a tunable white dimming module custom-designed by GRE Alpha to enable ON-BBL (blackbody locus), ZIGEN created the world's first ON-BBL 2-channel tunable white COB LED (the ZG7 series). This remarkable patented technology using 3 phosphor color ranges from 2000K (sunrise) to 5000k (sunset) which eliminates the unwanted pink found in conventional tunable white LEDs and expands the adjustable color range to align with human-centric lighting applications.

The kind of ingenuity and forward-thinking being exhibited by companies like GRE Alpha and ZIGEN are resulting in more sophisticated products that are improving the usability of indoor spaces and simulating the natural cycle of daylight that defines our 24-hour internal clock (circadian rhythm), enhancing pleasure, alertness, coordination, and mood. Whether in a commercial, residential, healthcare, or education environment, tunable white lighting can be adapted for virtually every occasion and activity...

• At home: The effect of tunable white LED bulbs can replicate a full morning sunrise for awakening and sunset to help with wind down for sleep by stimulating melatonin production. Cooler colored light can make occupants feel cooler on a hot summer day and vice versa.
  
  
• In the office: Midday, cool lighting (3500k) can optimize employee performance and keep them involved and engaged throughout the day while neutral white lighting (4200k) works for speaking or presenting to a group.
  
  
• In the classroom: With tunable white, the color and intensity of light can be modified to calm or invigorate students, focus their attention, support different levels of concentration for tasks varying in complexity, or even tell them when it's time to leave.
  
  
• In hospitals, nursing homes and assisted living facilities: Tunable white lighting systems can be used to replicate day and night for better sleep and alertness, improve patient rest and recovery, reduce agitation, and encourage healing from depression, seasonal affective disorders, and dementia.
  
  
• In museums and galleries: Tunable white fixtures can be adjusted to bring out the best light in works of art on display and provide maximum illumination without the damaging effects of UV rays. Some museums will use tunable white to replicate the time of day artists typically worked on the piece.
  
  
• In retail space: Varying light output and coloration provide flexibility to showcase changing merchandise at its visual best and create emotions associated with various brands. By creating a sense of comfort to the retail experience, longer stays are encouraged.
  
  
• In hospitality spaces: From the welcoming atmosphere of a hotel lobby to the glow of an intimate restaurant, tunable white colors can create attractive, comfortable, and functional environments that contribute to a feeling of hospitality and contentment.
  
  
• Correction of circadian misalignment: Varying light color and intensity may be used by medical professionals to treat jet lag, sleep disorders, and other conditions.
  
  

Clearly mood is a major player in tunable white, but aesthetic vision, usability and flexibility of spaces are huge as well. Versatile, long-lasting, and highly efficient, existing tunable white lighting can be modified in any space to adhere to the preferences of a new owner and give spaces the flexibility to change on a seasonable basis. More and more, when spaces are remodeled or rebranded, owners are opting to update lighting to tunable white.

Where GRE Alpha comes in

The key to achieving the perfect balance of color and intensity is the use of more sophisticated lighting control modules that allow for gradual tuning that has a smooth temperature gradient without color distortion. A perfect example of this is GRE Alpha's pioneering SLD DimTW2, a CV tunable white LED dimming module. This unique plug-and-play dimmer accepts 0-10V/1-10V control signal and enables smooth, dynamic color temperature shifts of 2000K to 8000K. It has opened ease of upgrade and options for color tuning applications that improve the dynamic of light.

With more new products and partnerships in development, at GRE Alpha you will always find solutions for a life well lit, with benefits far beyond illumination. For more information about GRE tunable white products, please visit the GRE contact page. You will find our team of experts ready and eager to provide the support you need.

ZIGEN Featured in LED Professional Review

It was not long ago that the ability to have control over the CCT (correlated color temperature) of your light source was inconceivable. Now, thanks to ZIGEN Lighting Solutions supported by GRE Alpha’s tunable white dimming module, the industry’s first tunable white COB LED product series has been introduced. Labeled ZG7, the On-BBL tunable white COB LED changes luminous colors following the blackbody locus (BBL) by just using a 2-channel input.

While conventional tunable white LED only starts from 2700K or above and can result in a pinkish color at mid-range, ZIGEN’s newly patented technology using 3 phospor color ranges from 2000K sunset color temperature to 5000K which eliminates the unwanted pink and expands the adjustable color range to human centric lighting applications. It is a major step forward in tunable white lighting that is being welcomed by architects, engineers and building managers alike.

Consider ZIGEN’s ZG7 tunable white series solutions to help maximize ambiance and well being for:

• Educational Spaces. Learning is enhanced when indoor lighting mimics the natural patterns of daylight and helps students to stay focused and alert.
• Healthcare Spaces. In healthcare, elderly care and assisted living facilities, tunable white lighting can be easily adjusted from cool to warm to optimize the healing environment.
• Office Spaces. The right light at the right time can optimize employee performance and keep them involved and engaged throughout the day.

Listed above is a mere sliver of the usage possibilities in ZIGEN’s new tunable white technology. According to ZIGEN management, they are planning to adopt this new technology to higher power COB and SMT solutions in the near future. GRE Alpha is proud to be an LED powering partner with ZIGEN and looking forward to supporting their progress in any way possible. About ZIGEN Lighting Solution Co., Ltd

ZIGEN Lighting Solution Co., Ltd. is an LED device company established in 2017. The company won the Hiroshima Venture award and makes innovative lighting LED devices continuously. Involved in the production and distribution of lighting LED devices with unique product design, their products have established reputation by quality and features not available from other LED suppliers.

About GRE Alpha

GRE Alpha® Electronics, Ltd. specializes in the design and manufacture of solid-state lighting power supplies and lighting control accessories, which are the lifeblood indoor and outdoor LED lighting systems. Our superior performance products are the power behind LED lighting systems. GRE’s unique modular approach provides ideal, easy to integrate powering solutions for new and existing installations.

GRE Alpha's SEL-20kA Surge Limiter Guards Against Transient Voltage Surges

Background

Your investment in lighting faces two types of very real electrical threats to the equipment itself and to the operator and the public safety.

• Lightning strikes in the vicinity, leading to galvanic or inductive coupling
• Lightning strikes on the LED streetlight or the power supply cable

(Source: LEDs Magazine)

The first threat is a momentary voltage or current spike that can damage or destroy your equipment. These can occur in both indoor and outdoor installations.

The second hazard, primarily if your lighting is outdoors, is the perpetual threat of lightning strikes. The long copper cables that carry power or data signals from LED power supplies or controllers can unintentionally mimic lightning rods, drawing in danger from the very sky itself.

Having appropriate protection in place to handle common power quality issues, such as over voltage's is important

GRE Alpha SEL-20kA Surge Energy Protector

The GRE Alpha SEL-20kA Surge Energy Protector is a surge limiter that provides maximum protection for your lighting investments. The UL Listed Class 2 device complies with UL1449, EN 60.364-5-534 and EN 62.305-1. The SEL-20kA provides effective surge protection against surge over voltages, providing effective coverage against both direct and indirect lightning strikes.

The GRE Alpha SEL-20kA Surge Energy Protector. Image source: GRE Alpha

This device is a UL Type 2 surge protection device (SPD), which means that it is designed to protect against 8/20 µs current waves. It provides protection against pulses of up to 20kA / 20kV and is designed to operate from AC line voltages ranging from 100 to 277, with a 320 VAC continuous maximum.

This surge protector protects against line to line and line to ground surges and includes a LED device status indicator.

The GRE Alpha SEL-20k Surge Energy Protector comes fully potted, which means that all unoccupied space with the device is filled with a solid or gelatinous compound. This makes it impossible for water to get in to cause short circuits or other damage. Additionally, during stormy weather, the air itself can be charged with electricity, and can cause electrical sparking. Potting fills all the empty space and eliminate either of these potentially disastrous outcomes.

GRE Alpha SEL-20kA Surge Energy Protector is designed to work the company's line LED Power Supplies. Image source: GRE Alpha

The unit enjoys an IP65 rating from the International Electrotechnical Commission (IEC). This means it is 100% protected against dust and is also protected against low pressure jets of water from all directions.

The GRE Alpha SEL-20kA Surge Energy Protector is a UL Listed Class 2 device that also complies with the UL 1449, CSA C22.2 NO. 269.4-14, CSA C22.2 NO. 269.5-15 and CE safety standards.

It operates over a temperature range of -40°C to +70°C, and over relative humidity of 5% to 95%. Unit size is 70mm (L) x 60mm (W) x 50mm (H). Read more

Specialty Solutions for Street Lighting

GRE Alpha provides a complete product line for LED street lighting. Products include LED power supplies as well as surge limiters, necessary components to protect against momentary pulses of high inrush current.

Application segments include:

• Street Lighting
• Pedestrian Lighting
• High Bay Lights
• Up/down Lights
• Flood Lights
• Wall Washers

GRE Alpha is a total solution for all LED lighting specialty solutions, these include:

• Architectural Signage and LED strips
• Horticultural Lighting, Grow Lighting
• Professional Lighting including Downlights and Track Lights
• Street Lighting and Bay Lightings
• Custom Solutions including Bespoke Design and Engineering
• Dim Control, Dimming Module Accessories

About GRE Alpha

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. Our superior performance products are the power behind LED lighting systems. GRE's unique modular approach provides ideal, easy to integrate powering solutions for new and existing installations.

DALI-2 is the updated and improved version of the DALI lighting protocol, which extends and enhances the strengths of DALI as a dedicated, standardized protocol for digital lighting control. In 2019 a number of updates were made to the DALI-2 standard that created some confusion. To understand the latest changes, it is necessary to be familiar with DALI basics.

DALI Simply Explained

First drafted in the late 1990s, DALI (Digital Addressable Lighting Interface) was the language developed to allow digital control, configuration, and querying of fluorescent ballasts, replacing the simple, one-way broadcast-like operation of 0/1-10V analog control.

DALI control signals are transmitted over two low-voltage wires that connect to each DALI ballast or relay, each of which has a unique address. Control commands are sent out over the wires to tell individual devices or groups of devices to turn on and off, dim up and down, etc. The devices even have the ability to report back to the controller indicating a lamp failure or how much power they are using.

DALI is an open protocol defined by the International standard IEC 62386 and IEC 60929. Using an open protocol means anyone can develop their own DALI devices, ballasts, relays, sensors, etc. While DALI’s impact has been far-reaching, as digital lighting evolved, the need for a DALI update became apparent.

Enter DALI-2 and the DiiA

In 2017, the original DALI standard was restructured and improved, upgrading it to version 2 of the DALI standard IEC6236. DALI-2 added new features including color control and introduced standardization of control devices including the addition of input devices such as light sensors, push button switches, and occupancy sensors, which are the “brains” of a DALI system. Backward compatibility has been maintained.

In response to industry requests for an independently verified DALI-2 certification program, came a new consortium (Digital Illumination Interface Alliance or DiiA), which is now the key organization for promoting DALI on a global basis. The more detailed and rigorous testing requirements enable DiiA member companies to certify that their products meet the requirements of the DALI-2 standard, including features that ensure interoperability.

DiiA organizes regular Plugfests, which are events to allow member companies to get interoperability of their products with those from other manufacturers. DALI-2 certification is granted only after DiiA verifies that testing is complete and successful. Certified products can be identified by the DALI-2 logo and are all listed in the Product Database on the DiiA website.

Here are the 2019 milestones from the DiiA DALI-2 timeline...

• Nov 2019: DiiA starts D4i certification of LED drivers
• Oct 2019: D4i specifications updated and new Part 351 published by DiiA
• July 2019: 500th certified DALI-2 device added to DiiA database
• June 2019: DALI-2 certification of sensors and input devices is now underway
• May 2019: First DALI-2 input device is certified by Zencontrol
• May 2019: Input devices added to DALI-2 certification program

GRE Alpha and DALI

GRE Alpha Electronics, Ltd., a driving force in the design and manufacture of LED power supplies and systems, has hit its own milestones with DALI. In November 2019, GRE became certified as one of the first and only DALI accredited test labs in ASIA offering full-service DALI-1 and DALI-2 testing. And, as part of their effort to deliver the benefits of DALI-certified dimming modules to lighting designers, GRE introduced two DALI-2 certified drivers which will be added to the DiiA database:

• SLD-DIM-DALI-B Intelligent DALI-2 Dimmer For Home Automation – With wide input voltage settings and compatibility with DALI enabled lighting control systems, provides flexibility and ease of use for home lighting automation projects
• GLD-DIM1-DALI Constant Current Output LED Dimming Module – Compact add-on for the GLV constant voltage type LED driver can be easily upgraded for constant current or constant voltage applications. Provides full range, flicker-free dimming.

With new test specifications in progress, you can expect to see many more certified DALI-2 products in 2020. Count on GRE Alpha to keep you posted on any further changes to the DALI-2 standard. For information about GRE’s DALI testing program or easy-to-install DALI compliant dimming modules, visit www.grealpha.com/contact.

Since dimming technologies made their debut in theaters at the end of the 19^th century, a lot has changed. Dimmable lighting is now widely available, and modern consumers demand lighting systems with a myriad of control possibilities, from complex color effects to timing to complete dimming capabilities.

LEDs are inherently dimmable which makes them ideal for applications where dimming is essential. Dimming results from controlling how much electrical power a light source gets. Seamless dimming is a vital capability in many applications as constant light flickering can lead to epileptic seizures, migraines, and visual impairment in some people.

LED dimming performance is dependent upon the driver capability and compatibility with the dimming equipment. A dimmable lighting system can mean significant energy savings without compromising the building occupants’ lighting experience. One way dimming can save energy is through gradual dimming as ambient daylight increases, also known as daylight harvesting. Lighting systems can also be programmed to dim specific zones as needed.

According to the U.S. Department of Energy, LED dimming technology saves energy, increases visual task performance, enhances ambiance, requires fewer light sources, enhances space flexibility, and offers improved component lifetime. The Department of Energy expects LED technology to become the preferred method of lighting in both residential and commercial applications by 2025.

There are four basic types of dimming technologies:

0-10V DC Dimming

DC dimming is a popular method for lighting applications that require quality dimming. While it does require rewiring in retrofit applications, it can deliver full dimming capabilities and is very efficient. As with other dimming technologies, getting to desired effect requires careful consideration of component compatibility. For example, a 1-10V controller is compatible with a 0-10V LED driver. On the other hand, a 0-10V controller is not compatible with a 1-10V LED driver. As a result of this confusion, 0-10V controllers and LED drivers are now standard.

Digital Dimming (DALI, DMX)

Digital dimming is common in theaters, auditoriums, and similar applications. It relies on a control system that organizes luminaires into zones. Customers can operate the system wirelessly via a smartphone, which makes the technology appealing to the masses. Originally used almost exclusively in theatrical applications, this type of tuning is now being used to create high quality effects in commercial and residential spaces. Manufacturers of products from residential lamps to commercial luminaires have now implemented full-color tuning. Many systems have adopted DALI or DMX control types.

DALI (Digital Addressable Lighting Interface)

DALI dimming is a type of digital control based on a de-centralized system. It is a nonproprietary standard and is known to be flexible in its deployment and use. Like the 0-10V dimming system it requires a control cable. However, with DALI, the control cable can be run between multiple fittings. Multiple control units are controlled individually or in broadcast mode (with up to 16 groups).

Digital Multiplexing (DMX)

Like DALI, the DMX standard allows for digital control of individual fixtures via a low voltage communication protocol but accepts larger range of digital addresses (512 unique addresses for DMX versus 64 for DALI). The DMX signal is generated by a lighting control system and requires dedicated cabling between the controller and driver. It offers fast centralized control.

More information is provided at :DMX Lighting Controllers: Continued Innovation in LED Lighting and DALI VS. DALI 2: Why You Must Know the Difference

Forward phase control (leading edge waveform, SCR, Triac)

In this dimming method, the diode is energized only during the last portion of each power line half-cycle. Dimming results by turning the light on and off at a rate of approximately 120 times per second, a rate that is imperceptible to the human eye. 

Forward phase control dimming is commonly used in retrofit projects because it is generally compatible with existing switches and drivers, and it doesn’t require the labor to install new wiring. While this method reduces control over dimming levels, it can achieve 80-85% driver power efficiency and hence significant savings in overall cost.

Reverse phase control (trailing edge waveform)

In the reverse phase control method, the diode energizes during the initial portion of each power line half-cycle. This is the preferred dimming method in electronic low voltage (ELV) systems. There is no special stabilizing circuitry needed, meaning that flickering, power surges and other problems are nonexistent as there is seamless communication with the driver.

LED Dimming Solutions

Use a dimmer designed, tested, and UL - listed for your specific lighting source. GRE Alpha^® Electronics offers a series of dimmable solutions for any application. The XLA series incorporates pioneering deep dimming technology that results in 0-100% flicker-free dimming. GRE’s online product matching portal makes it easy to source the right power solution for any application.   

The most vital thing to remember when procuring LED dimmable systems is that the all component technology must be compatible. This means the controls, driver, and bulbs must be designed to work together. Manufacturers often list specific recommendations for LED drivers and controls for luminaires, so it pays to do research.

As we continue to realize advancements and increasing affordability in dimming technologies, new generations of LED drivers are set to provide dimming as a standard feature.  Lower cost digital controllers and drivers will lead to more widespread LED use and greater energy savings.

About GRE Alpha

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. Unlike many in the LED industry, GRE Alpha focuses on a modular approach. GRE Alpha products can be used either in conjunction with existing systems or with new setups.

With more than two decades of power conversion expertise and a commitment to innovation, GRE Alpha engages with industry pioneers to deliver highly efficient, installation-ready and agency-approved LED power conversion products for a wide variety of industry applications.

www.grealpha.com

References
U.S. Department of Energy, LED Dimming: What you need to know.
Canadian Consulting Engineer, Dimming Protocols.