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Digital Ceiling and the Semiconductor Blues

- March 28, 2016 - 2 Comments

As part of the work we did for TechWiseTV 181: Shining a Light on the Digital Ceiling, I had a chance to meet and work with some really smart people from Cree. Cree pioneered much of what we are now seeing as commonplace when it comes to LED’s. They have also come in as a key partner in our Digital Ceiling. Cree was founded in 1987 and brought the first blue LED to market in 1989. LED’s are considered pretty darn flexible these days…its hard to imagine there is a color they can’t make.

In the full length show, I drew some connections between the invention of the first electric ‘network’ and how the common storyline was usually how (AC) ‘alternating current’ from Nikolas Tesla had beaten ‘DC,’ Thomas Edison’s ‘Direct Current’. Now for the sake of space, I largely skipped over the mass market adoption of fluorescent bulbs in my cherry picked historical account (nothing to do with how much money I have personally wasted on short lived CFL’s…). LED’s have turned out to be a much bigger deal now of course. But as new as they are…I never realized just how long they had been around and why their growth had been so limited until, relatively speaking, recently.

Much of it had to do with the color blue.

Light-Emitting Diodes (LED’s) create light by sending an electrical signal to a sandwich of semiconductor materials to create electromagnetic radiation that we see as light or ‘Electroluminescence’. It’s actually a specific wavelength of light depending on the chemical make-up of the materials used.

LEDs offer a higher level of efficiency than incandescent lights primarily because they convert electricity DIRECTLY into photons of light. Now this is not a ‘new’ discovery. It dates back to 1907. We have had LED’s in our life in the form of practical electronic components since 1962.

Visibile Light SpectrumEarly LEDs emitted a low-intensity infrared light that we cannot see with the naked eye…(in fact, they have done quite well with the ‘collection’ of remote controls I still have and some of which, I still use.

The first VISIBLE-light LEDs were also of low intensity, and limited to red and it took another 10 years to get green. Yellow came along as well and most of had them around us in the form of circuit board lights, digital watches and then, with this ideal color combination…traffic lights by the 1980’s.

So LED’s have been rocking it for years…as long as you only needed a few specific colors. Red and Green were good but …the holy grail was BLUE. BLUE would allow color mixing (think RGB), to create what the human eye would perceive as white. How does BLUE become WHITE?A color of light we use for just about everything. For years physicists thought bright blue was an impossibility. In fact, it was such a big deal, that the 3 physicists who figured it out, won the Nobel prize in 2014. It was Gallium nitride that became their key ingredient but growing big enough crystals was the stumbling block. Now it became possible to make white light…which is pretty much the light we need for everything except residential disc jockey gigs, (that is another story).

The next thing to work on was getting it bright enough and at a low enough cost to make it available to a broader market. This is where Cree comes in. Cree was founded in 1987 and brought the first blue LED to market in 1989. Cree was working with Silicone Carbide (SiC) as a platform material and they had quickly recognized that solving the brightness issue would be key to expanding the market.

Christopher Helman wrote a great article in Forbes back in 2013, ‘How Cree perfected the 20-year lightbulb.’

At first Cree just made the chips and sold them to the LED makers; early uses included backlit car dashboards and cellphones. The potential seemed so great that in 2004, analysts were calling Cree “the next Intel.” But white LED lights weren’t ready for the residential market. Early fixtures cost too much and suffered from another at-that-point-un-resolved problem: LEDs are a directional light source. Think of them as a weaker version of lasers, only able to cast light in one direction. That’s fine if you want to spotlight something but more of an issue if your “aim” is to replace the all-around glow of incandescents. LED makers started marketing what they called “down-lights.” I have had them in the last few houses I owned…but I called them ‘can lights,’ those embedded black holes in the ceiling.Can Light

Industrial customers were an easier target in the short run with LED’s replacing those sodium vapor streetlights, school gymnasiums (always sticks out to me) and large warehouse spaces.

Mass market adoption would require an incandescent bulb replacement and that form factor ’type A’ would take awhile. This ’Type A,’ scree in standard that I always bought in bulk from the hardware store…was really important of course. This ‘incandescent’ bulb that dates back to Edison…but more importantly, fits in so many places, the ‘luminaries’’, we all already have. Cree worked hard to figure this out and they worked in secret. They would even wait until nightfall to remove all the broken glass from the failed experiments so no one caught on. This was not easy to accomplish…there were different ways to potentially accomplish these design goals.

The key for getting this form factor lay in a structural redesign of the middle of the bulb, called the filament tower, where 10 or 20 LEDs of varying colors could be arranged. This allowed the individual light sources to overlap, creating an omnidirectional glow.

Between 2011 and 2012 alone, global sales of LED replacement bulbs increased by 22 percent, and the cost of a 60-watt equivalent bulb dropped by nearly 40 percent.

Cree worked closely with Home Depot in the beginning, and when those prices dropped, I even got in on it and replaced all of those temperamental CFL bulbs in my house. I have had them less than two years…but none have gone out yet…and the light is instantaneous. No warm up. I love that. I am now close to using nothing but LED.

So why is Cisco so excited?

An LED light source only requires four to five watts of energy to produce 450 lumens while an incandescent bulb requires 40 watts to produce the same amount of light. Now, its getting hard to even find these old school incandescents. This low power requirement puts LED lighting within the range of what our PoE switches can provide. In other words, your network switch, which already delivers data and electricity to office phones and wireless access points, can now be used to power the building lights. This is low voltage, (direct current), which is much easier to work with than the high voltage standards (requiring licensed electricians). LED’s allow us to provide the electricity from a data switch you may already have. This is the kind of innovation that pays for itself as well. Bypassing high voltage cabling and simplistic fluorescent lights that tend to get installed by default these days…can be offset completely by the combination of data cabling and LED fixtures that are now possible.

We can now run the lighting for an entire commercial building off of Cisco switches. This enables a significant reduction in complexity as it does away with high voltage wiring and provides a foundational flow of data that can be tapped into for things that have been impossibly or prohibitively difficult before.

And that is just to get started.

The big upside for a ‘Digital Ceiling’ is beyond the initial savings…the upside is in the platform for innovation now enabled.

Building control systems have been around for awhile. Various sensors that can be used to measure temperature, humidity or just about anything you can think of…have all been around. They have never really taken off in the market however…why is that? Because they are a pain the you-know-what. Everyone of these sensors has a slightly different take on the network protocols they use, where they get their power, etc. In a nutshell, each time you want to start working with something in this space, you have to accept that it will mean the creation of ‘another network’ which means another management point as well. It will be cool at first…but the unique nature of it, as compared to everything else you have to do…the charm wears off FAST. Don’t even think about trying to blend data from multiple sensors to get more unique measurement…you are on your own with either a custom job or a commitment to one small manufacturer you hope will be around for the long haul. As we have learned with so many other technologies coming and going…a foundation of Internet Protocol and twisted pair could make all that pain go away.

The use of building control systems and various types of sensors are nothing new these days. But they are a challenge to get real use out of because they require the addition of yet another network. A great many wireless technologies have been trying to solve much of this but they suffer from propagation issues in the construction, bandwidth constraints and power consumption challenges. All of this goes away when there is digital ceiling foundation.

NOW things can really get interesting.

Don’t miss our LIVE workshop on Wednesday, March 30 at 10 AM PST. This same link can be used for the replay if you don’t make it live.

It’s not often that we slow down and think about the light we depend on for everyday tasks. It was not that long ago when the economy was ruled by the rhythms of the available sunlight each day. So even if we do take the humble light bulb into consideration, it is still amazing how things are beginning to change. This excerpt from our full episode ‘Shining a Light on the Digital Ceiling’ highlights the role that Cree, Inc plays for the quality we expect from our LED lights and the importance of the color blue.

Watch the show or read the blog for more information.




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    When I first read about this, I told our facilities manager. His response was "well can your switches power 1 million watts?" I don't think he fully gets it. The LED uses so much less power, and we have only converted a small percentage over to LED.

      Peter, thanks for trying to share it with him. You hit on one of the challenges...there is a mind shift that has to take place no matter how much sense it makes. It reminds me of our pre-IP telephony days...that used to seem so strange. Thanks for reading and watching! Robb