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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.

LED lighting is becoming the new design standard for its efficiency and longevity. But hand in hand with these more efficient lamps are lighting controls such as dimming. While dimming has been around for decades, it continues to grow in popularity. While it still provides ambience for a space, architects and building owners are now discovering the energy benefits of dimming. Finding a dimming driver that can smoothly transition between lighting levels is critical to achieve this. Silicon-controlled Rectifier dimming, or SCR, has been a popular method of dimming for decades due to its stability. Also known as an autotransformer dimmer, this device has been used with incandescent lights for years to provide consistent and inexpensive dimming solutions. Now that LED lights have gained popularity for their efficiency, drivers must adapt to provide the same level of reliability using new methods. Even with this challenge, there are great solutions. Lighting professional have found that using SCR dimmable LED power supplies to be one of the best and most efficient ways to provide consistent dimming.

What is SCR?

This common method of dimming uses a silicon device called a thyristor to turn the waveform on halfway through its cycle, which allows for power delivered to a lamp to be varied. This method was developed in the 1970s and has been the most commonly used dimming technology for decades. It accomplishes this by varying the point at which the waveform turns on which alters the amount of current or power that goes to the lamp. This is the simplest and cheapest method of dimming. One drawback of SCR dimming is the hum, or singing, sound it makes when the voltage drops. However, this is and has been eliminated with a choke fitted to the dimmer module. The choke can reduce the rate at which the current increases, thus eliminating the sound.

Why It’s More Efficient

Dimming has now become a method to reduce electricity because modern dimmer drivers such as those that use SCR can now cut the supply of current on and off at rapid speeds. This method interrupts the current during an alternating current (AC) half-cycle. This allows you to achieve the dimming effect of a design while maintaining an efficient lighting system. Using dimmers also prolongs the life of light bulbs. By reducing the amount of power to bulb, it experiences less stress and heat. LEDs benefit from this because the dimming range is broader. LEDs can turn down to less than one percent of full output compared to compact fluorescent lights that can only reach 10 to 30 percent. With an LED lighting system, you can achieve the desired aesthetic while also maintaining lower energy bills and a system with an extended lifespan.

Best Applications for SCR Drivers

While LED dimming may be advantageous, choosing the right power supply is the key factor in improved efficiency and overall operation of a lighting system. SCR has the advantage of being a well proven method of dimming for decades, but the technology requires some tweaking to adapt from the standard incandescent lamp technology to LED. For this reason, it’s important to consider the applications best suited for SCRs. Because of their singular forward-voltage only they are best suited for medium to high voltage applications such as lamp dimming, power regulators and motor control. However, some of the more sophisticated products on the market such as GRE’s UL/cUL Listed Class 2 Linear Lighting Pro Constant Voltage LED driver can compensate for the lower voltage ranges and forward phase types such as SCR.

SCR dimming drivers are a widely used, reliable, and inexpensive method of dimming technology. But to marry them seamlessly to new LED technology, it is necessary to consider the application. Choosing a driver module that can also overcome flickering or inconsistencies at low voltages should also be considered. A TRIAC dimmable LED driver delivers a wide and constant dimming range that is free of flicker with best-in-class dimming performance, and high efficiency.  Supporting products include the constant current  XLA with flying leads. The unit has wide dimmer compatibility and supports most phase type dimmers in the market, including leading edge and trailing edge, electronic low voltage (ELV), TRIAC, and SCR dimmers. When chosen carefully, though, SCR drivers can be paired successfully with LED lighting systems to provide not only superior, efficient lighting schemes, but also the most reliable, simple, and cost-effective solution. 

The state of California is well-known for its strict environmental regulations which stem from the 1970s record air pollution levels to the brown-outs of the early 2000s.  While often criticized for its rigid regulations, California has managed to improve air quality significantly since the 1980s and now aims to reduce the state’s energy consumption to avoid future energy crises. 

The state’s Title 24 is a set of regulations also known as the California Building Standards that specify how buildings are constructed in the state.  The California Energy Commission (CEC) is tasked with creating, revising, and amending the code.  The Joint Appendix 8 of Title 24 (JA8) took effect on January 1, 2017.

JA8 standards focus on several key areas to improve the energy efficiency of new homes, including requiring all newly-constructed single-family homes, townhomes and dwelling units of new multi-family buildings to use high efficacy lighting. 

To qualify as “high efficacy,” light sources must meet the requirements laid out in the updated code.  JA8 regulations focus on performance and lighting quality to increase consumer implementation of high efficacy lighting and to give consumers more choices in lighting solutions. 

Lighting products must apply for JA8 certification and compliance through CEC.  Products must meet specific efficacy, power factor, correlated color temperature, color rendering index, lifetime, dimming,  flicker requirements, and more.  A partial list of JA8 qualifications requirements is available here. 

Products that must meet JA8 requirements include:

• Ceiling recessed downlight luminaires
• Light sources in enclosed luminaires
• LED luminaires with integral sources
• Screw-based LED lamps
• Pin-based LED lamps
• GU-24 based LED light sources

Recessed downlight luminaires and enclosed luminaires must contain a JA8-complaint light source and meet the elevated temperature requirements.  Light sources which automatically qualify as high efficacy must still meet JA8 requirements if installed in a ceiling recessed downlight or enclosed luminaire. 

To obtain JA8 certification, manufacturers must test their products at an accredited test laboratory and submit the results to the CEC.  To produce compliant LED lighting products, manufacturers must also keep in mind the LED driver, which is an integral part of any lighting system. 

GRE Alpha offers a full lineup of products that are suitable for JA8-compliant lighting systems.  All GRE Alpha dimmable modules can provide dim-to-zero performance, whereas most of the market’s dimmable options can only dim to about 5%. 

High efficacy luminaires require high-efficiency components.  GRE Alpha XLD series LED drivers can achieve high efficiency up to 92% to power JA8-compliant luminaires.  Normally, efficacies over 90% are considered high in the market. 

As we become more conscious of the need for energy efficiency, more and more states will likely follow California’s lead and adopt energy efficiency building standards.  GRE Alpha strives to be a trailblazer in this challenge and designs products in anticipation of future energy needs.

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. Their 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

California Lighting Technology Center (CLTC), High Efficacy Lighting for Residential Applications.

California Energy Commission, 2016 Building Energy Efficiency Standards Fact Sheet

Smart LED Luminaires Enable IoT Integration

Compared to incandescent and fluorescent lighting, LEDs offer many advantages including long lifetime, higher energy efficiency, lower life cycle costs, and improved light quality. But LEDs are more than just replacements for traditional lighting solutions. They are also inherently electronic devices, and when controlled with smart dimming modules and power supplies used for smart home lighting and building lighting, LED luminaires can easily be integrated into the smart networks and digital control systems that are beginning to comprise the Internet of Things (IoT).

There’s been considerable activity in the lighting industry related to IoT, and the subject was a major topic of interest at the 2018 LIGHTFAIR® International Trade Show in Chicago. GRE Alpha displayed several products at the show including DALI dimmers that are key components in IoT-based LED lighting systems when integrated with power supplies used for smart lighting, sensors, and modules that enable WiFi dimming and control through smart networks.

IoT-based LED lighting has the potential to offer important features and capabilities such as:

• Ease of monitoring LED luminaire status and the life cycle of LED lighting elements
• Generation of analytics to improve lighting system performance
• Tracking of user behavior to help optimize the user experience in a home or building, or to attract attention to product displays in retail spaces
• Personalization of lighting experiences by connecting, for example, to a profile on a user’s smart device

Since lighting is everywhere in a home or building, and since LEDs are easily integrated into digital controllers, LED luminaires can potentially offer additional functionality such as air quality monitoring, room temperature monitoring, communication with other smart devices over WiFi or power lines, and even visual light communication (VLC) to other smart devices. With the potential to serve in so many roles, LED lighting systems can serve as key components of backbone of the Internet of Things in homes, commercial buildings, and industrial applications.

A New IoT Lighting Standard

To guide manufacturers in developing IoT-based LED lighting solutions, the IoT-Ready Alliance, which includes leading lighting, building management, and IoT companies, introduced the first IoT interface specification for enabling future-proof intelligent buildings. Their Interface Specification V1.0 defines a socket that allows any IoT sensor or control module to connect to a luminaire or other building system. The standard includes specifications for mechanical, electrical, and software, and it allows for parts to be retrofitted or replaced on site. It is independent of network protocol, which means that IoT-compliant products can connect via wireless or wired networks to integrate with LED lighting systems. Supported networks include Thread, BLE, ZigBee, Z-Wave, Wi-Fi and IP/Ethernet networks.

The IoT-Ready Alliance specification V1.0 is designed to enable rapid growth in the IoT lighting sector and to ensure smart buildings incorporate the full advantages of LED luminaires and power supplies used for smart lighting now and in the future.

GRE Alpha is working with industry leaders and standards organizations to create next-generation IoT-integrated LED dimming modules and drivers. A current path to IoT-ready lighting solutions includes LED power supplies coupled to dimmers that conform to the Digital Addressable Lighting Interface (DALI) protocol. DALI dimmers such as the GRE Alpha SLD-DIM DALI dimming module provide flexibility and ease of use for smart home lighting automation projects, while the GLD-DIM module, which has an available DALI version, is a compact dimming module that serves as an add-on for constant voltage LED drivers. Both modules are fully compatible with LED power supplies used for IoT lighting and can enable network and WiFi dimming when coupled with power supplies used for smart lighting.

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. Their 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

More and more architects and building managers are understanding the benefits of lighting to our health and well-being. Studies show that lighting in office buildings can have major impacts on employee engagement and performance. With workers clocking in more hours at the office than at home each week, considering the health implications in the work environment is necessary to keep workers not only productive but also healthy. While many strategies to improve air quality and general environmental health in the workplace have been implemented in modern buildings, lighting is one strategy that can have profound affects on not only physical but also mental health of employees. One of the major ways this can be used is with tunable white lighting.

Studies show that lighting in office buildings can have major impacts on employee engagement and performance.

What is tunable white?

Tunable white, or Kelvin changing, LED lighting allows for lighting colors to be adjusted to produce either warm or cool white light. LED lighting mixes red, green, and blue channels to deliver a range of colors across the color spectrum. Tunable whites work similarly by adjusting the color temperature of a white light's output. With tunable white, there are two controllable LEDs: one warm-white color and a second cool-white color. These can be utilized in a variety of ways from simplistic to sophisticated:

Two lines of LEDs — the most simplistic method of achieving temperature variance in white LEDs is cross dimming between a warm white LED and a cool white LED. When put side by side in an aluminum extrusion with an opal diffuser that does the color mixing, you have a very basic way to achieve tunable white lighting.

Multi chip — this type of temperature variance lighting utilizes tiny LED chips combined in one module. In this way, the color mixing occurs as the light leaves the module. The small size of this type of technology means that it can be used for several applications such as downlighting.

What's key to a good tunable white lighting system is color rendering. Deciphering how well colors look when warm and cool channels are mixed together is how to effectively discern the quality of your tunable lighting system.

Applications for tunable white

There are a numerous reasons why tunable white lighting might be preferred for an architectural space, but in the context of occupant well-being, there are several key reasons why to choose it. It can be discerned that artificial light that most resembles daylighting can be good for natural body systems and influence overall health. Some of the ways this can affect it are:

1. Provide Apparent Cooling or Warming: by adjusting the coolness or warmth of the white light, a space can appear to be cooler in hotter climates and warmer in colder climates.
   
   
2. Simulate Daylight: Studies have found that lighting has profound impacts on our health. That's why there has been such an emphasis on daylighting design in sustainable design where occupant health is considered an important element.
   
   
3. Behavior Control and Focus: More studies have found that color temperature can also have a profound affect on attention and focus. In classroom environments, it can be used to calm students say before they begin a test or invigorate them to pay attention during a lecture.
   
   
4. Support to Human Circadian System: One widely known fact about effect of lighting on occupant health is its role in circadian rhythms. Circadian rhythms are like an internal clock that tells our bodies when it is time to wake and when it is time to sleep. Buildings have historically had a negative affect on these natural biorhythms by providing few windows for natural daylight and harsh lighting that tricks the human body into thinking that it is day time.

Tunable white lighting is being used in everything from nursing homes to treat dementia to psychiatric hospitals to curb aggressive behaviors. This method of adjusting for warm white lighting to cool white lighting to mimic outside conditions can evoke calm to alert behaviors in individuals that are serving as more gradual and holistic methods for treating mental disorders.

Tunable White Lighting Control Modules Key for Smooth Temperature Changes

The key to having a tunable white lighting system are the lighting control modules. The driving principle behind lighting temperatures is seamless adjustability. This means using lighting control modules that allow for gradual tuning that has a smooth temperature gradient without color distortion. Using more sophisticated LED modules is key to consistent color but lighting drivers can provide consistent temperature changes without noticeable flickers or color inconsistencies. And high-quality dimming modules can make installation simple to integrate, which is crucial when you are dealing with numerous lighting systems in a building. This can make it easier to provide lighting temperatures for interior areas of a space that depend entirely on artificial lighting.

Lighting has always been a profound design element that also is crucial to functionality. Most of any enclosed space is useless unless it contains some type of lighting to illuminate it. But with most people spending upward of 80-90% of their time inside buildings, more attention is being paid to the role that lighting has in our overall health and well-being. It's known that light from the sun provides us with necessary vitamin D and regulates are circadian cycle. But now more studies are being conducted that indicate lighting has a noticeable affect on our mental health. Meaning providing the right type of lighting is essential to activate certain cognitive responses. Lighting temperature is one element that can effect these responses, and should be carefully considered in a design to trigger the right moods of occupants.