Integrating Touch User Interfaces with LED Lighting

Touch based user interfaces controls have become common for controlling consumer electronic, commercial, and industrial systems. Most recently, the architectural marketplace has been quick to incorporate touch controls with LED technology.  At the May 2012 Lightfair convention in Las Vegas, dozens of touch based light control systems were showcased.  In fact, the Illumination Engineering Society (IES) has an excellent overview topology (publication TM-23-11) on the structure of an LED control system that could feature a touch based interface.

Reprinted with permission from Lighting Control Protocols (TM-23-11) by the Illuminating Engineering Society of North America.

For this discussion, we’ll focus on the “front-end” of the diagram. The most common way to detect a touch is by indirectly sensing the conductive mass of the human finger. Sometimes referred to as “capacitive” touch, this technology relies on detecting an electric field disruption of an approaching finger with a sensing electrode below a dielectric decorative substrate like glass or plastic.  Successful specification, design, and implementation of a touch-based user interface require a basic understanding of the active elements that comprise the system.

The dielectric decorative substrate is best described as the surface that a user touches when interacting with the interface. Typically constructed of glass or plastic, it serves as the primary aesthetic element in the product’s user interface design. In the case of touchscreens, the decorative substrate is usually planer and constructed of glass. In the case of discrete touch points, the geometry is almost unlimited with touch points integrated into many surfaces (commonly injection molded decorated plastic). The decorative substrate can also be backlit for aesthetic or functional purposes.

The electronic carrier is the element containing the sensing electrode structure and interconnects for the touch user interface. Discrete touch points (fixed touch points behind decorative icons) frequently use rigid FR4 printed circuit boards and touch screen use transparent conductive electrodes. Electronic carriers can be in the form of an external circuit or integrated with the LED driver. When designing touch solutions, thinner is better. A thinner decorative substrate and a thinner electronic carrier result in better signal to noise ratios resulting in a more robust touch solution.

LED drivers that are microprocessor based become excellent candidates for an integrated touch control, particularly if the driver circuit is co-located with the user interface. Since many microprocessors can be configured as touch controllers, cost is reduced with a simple solution. Several manufacturers offer low-power touch controllers that are suitable for battery operated “touch” remote controls which can connect to the LED driver using a wireless protocol such as ZigBee.

Norlux has extensive experience in the design of LED Drivers and has developed touch controls for the Architectural market. From simple on-off switching to full wireless intensity, color, and saturation control, Norlux is your one-stop partner for LED lighting and control solutions.

References
IES (Illumination Engineering Society) publication TM-23-11 (http://www.ies.org/PDF/Store/TM-23-11_FINAL.pdf)

LED Downlights – A Hot Trend in Architectural Lighting

With advancements in lighting technology, LED downlighting is an exciting option for architects and builders today. More people are becoming aware of the numerous benefits of choosing LED downlighting, and how it brings a modern dimension to home and office lighting. There is no doubt that a well-placed LED downlight can create a sophisticated, elegant and highly customized look in commercial or residential buildings. They excel at highlighting architectural features of interest, while drawing attention away from less exciting elements. LED downlights are widely used in bedrooms, sitting rooms, reception areas, display cases, cabinets, offices, art displays, bars, hotels and lobbies.

So why are LEDs becoming so popular in architectural lighting applications? With near perfect lighting effects, LED downlights depict an atmosphere of comfort and warmth. Add a dimmable function, and they not only adjust light output to fit any desired mood, but also conserve energy and lengthen the LED lifespan in the process. Beyond mere aesthetics, the inherent attributes of LEDs and their resultant benefits make them an ideal candidate for downlighting. 

• Lifespan: LED downlights are ultra-durable with a lifetime of over 35,000 hours (average), which is roughly equivalent to a lifespan of 20-25 years with normal usage.
  
• Temperature: LED downlights produce less heat than traditional lights, increasing safety by minimizing fire risk.
• Energy Efficiency: With high efficacy of LEDs and a long lifetime, LED downlights can save 70% on energy bills when replacing conventional recessed lights and incandescent lights.
• Maintenance: LEDs do not require much maintenance inherent with frequent lamp replacements. The low operating temperature of LEDs helps reduce air conditioning and maintenance costs as well, saving money long term.
• Color: LEDs for lighting applications have been designed to achieve a warm, white light that ranges > 90 on the color rendering index (CRI), and are described as “eye comfortable”. This light brings out the details of the decor, subtly improving aesthetics and mood.
• Safety and health: LEDs emit no ultraviolet rays or toxic substances (mercury). There are no environmental hazards to be concerned with when disposing LEDs either; heightening the overall “green” aspect of any space. Moreover, the lack of Infra-Red and Ultra-Violet rays emitted by LEDs means the light is healthier and less harsh, putting inhabitants at ease.

While some might balk at the slightly higher price of LED downlights, such amounts can be recovered relatively quickly since consumers are assured of significant energy saving over the lifespan of the product. LED users will enjoy excellent quality of light for their home or building, at a more affordable monthly power rate.

Increasingly, more professional manufacturers and suppliers of LED down lights have emerged. Now one can choose the right LED downlights with affordable prices and guaranteed quality for not only commercial applications but residential lighting as well. Contact Norlux today for a consultation on your LED lighting project.