Since dimming technologies made their debut in theaters at the end of the 19th 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:
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 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 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).
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
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.
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.
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.
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.
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