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LED Technology in Tensor Desk Lamps; Plus the Incandescent to LED Bulb Chart.
Previously we sat down with Michael Islas, one of our top engineers here at Evolution Lighting. We asked Mr. Islas several questions and he shared LED insights that you should check out if you haven’t already. In the second part of our interview, we’ll dig deeper into the LED landscape.
Evolution: Speaking of the wavelength color, one of the innovative new additions we’re incorporating into our products is color temperature control. How is that technology tuned into LEDs?
Michael Islas: [For color temperature], you would start at the core technology of an LED. Most white light LEDs are from a blue diode. The way it becomes white is that they use layers of phosphor. The phosphor composition is what determines both the color, as in color temperature and its CRI (Color Rendering Index) capabilities. To have good color rendering and the color you want, you need a more complex phosphor system. In terms of how they do the tuning of it, in most systems what they do is they’ll have two banks of LEDs. You have one bank that is a low CCT (Correlated Color Temperature), and you have another bank that is a high CCT, and you’re able to access the full range in-between by dimming one bank and brightening the other, and vice versa. For example, if you had a 3000-6000 CCT control, that’s because you have a bank of 3000 and one of 6000, and you’re able to select ranges in-between by brightening the 6000 one and lowering the 3000, and then balancing them out as you go through the full range.
Evolution: So that happens at the construction level. Correct?
M.I.: Right, so in most of these task items [i.e. Tensor Desk Lamps] it would be done through the driver. The driver controls two strings of LEDs and as you’re digitally pushing buttons to select the color, which tells the driver to ‘put more current into this string, and reduce it in that string.’ So it balances it out.
Evolution: Let’s dig deeper into the technology. Energy efficiency is a buzz word that people like to hear in many products out there, and LED is no different. What makes LEDs energy efficient?
M.I.: It’s a completely different technology from incandescent. Like we said, incandescent, you’re heating up a wire until it starts glowing, but with LED, you’re using properties that already exist in semiconductors to create light. Using semiconductor technology to do things very efficiently and use the characteristics of the atomic level of electrons and photons to our advantage. We’re not using heat. Heat is considered one of the most inefficient forms of energy. Thanks to the way the technology works, every year, [engineers] are able to make more and more lumens per watt, more and more lumens per energy used.
[Lumens per Watt (lm/W) is the amount of electrical energy required for an output of light.]
Evolution: Moving on, another buzz word that continues to flow around the lighting industry and its products is ‘integrated’ lighting, or eliminating bulbs to have the LED diodes directly in the fixture. For our consumers, what would you say is the benefit of buying an integrated light fixture as opposed to the traditional bulb fixture?
M.I.: There are tradeoffs. If you’re going strictly for illumination, integrated is a pretty safe bet. Integrated eliminates a lot of inefficiencies of the bulb. The bulb is difficult because you’re fitting a lot of stuff into a very small space. That little lightbulb has to handle all of the heat being generated, it has to handle the size of the driver –which is a confined space for the driver– and it has its own lens. Another factor is that in bulbs, you typically have to create light in many directions. And to the credit of the incandescent, they illuminate in all directions. LEDs, traditionally, are a one direction light source. They generate light upward. If you want to use an LED to create a 360 degree light distribution, you’ve got to pull some optical tricks. Granted, that is an inefficiency, and you can lose light doing that. But with integrated, you eliminate the bulb housing confining the driver, and you eliminate that optics issue.
Please check back with us next week to catch the final part of our interview with Mr. Islas. Part 3 is coming soon, where we will talk more about the LED technology in our Tensor Desk Lamps.
To provide a clear buying guide for LED bulbs, we’ve created a handy table that details the traditional incandescent bulb wattage and its LED equivalent.