Archive for the ‘General Commentary’ Category

My first LED fixture - 2004-2006

My first LED fixture – 2004-2006

This is my last bit of housecleaning from blogs being shut down, for the archives. KLW

This fixture is my very first LED light. It started life to be a halogen fixture in 2004, that sat on a workbench waiting completion. The first head got so hot from the 50W 12V light source, it was dangerous, so it sat as I decided what to do with it.

In 2005, as LEDs became viable for lighting, I pondered using them to replace the halogen source, but they delivered so little light, the end product was useless as a desk lamp, so it sat some more. One idea was to insert a Lamina BL3000 LED into the head, but the driver was huge, the light output too little, and the heat still an issue.

Then, in early 2006, while at Visa Lighting, Don Brandt (an engineer working with me at Visa, formerly from Emteq, now working at Cree I believe) were talking through ways of applying the latest mid-power LEDs using a simple PCB. We decided to give it a shot and built a board populated by a vendor with 8 Nichia LEDs. The inspiration struck to power these LEDs with two Xitanium drivers, which at the time were un-potted prototypes, so cutting them out of their housing to be installed in clear tubes to show their interiors off was easy enough. Two push-button switches activated the drivers for a high-low effect, and a heat sink was made up of a machined aluminum block installed in the head where the original halogen lamp and reflector once lived. More details and images of this can be found on the Lumenique archives for the Ratchet fixture.

The fixture itself is made of welded steel structure with a brass head and fiberglass tension springs. The head can be raised an lowered with a ratcheting action, staying level at any height. In the end, I left this fixture with the owner of the Oldenburg Group (owner of Visa Lighting) as a parting gift as I moved on to focus on Lumenique and SSL exclusively.

nikola_tesla[1]A bit of housecleaning from another blog site I am shutting down. Thought it worth keeping alive and the man in our thoughts, from 2008. KLW

If you are a fan and gear-head for volts and lighting, you have to be familiar with the guy that had a huge  influence on our modern environment. This is Nikola Tesla, an immigrant from Croatia that thought beyond direct current from batteries and heated filament electric lamps. He once worked for Edison, but found him dull and uninspired. The two inventors had dramatically different styles. Edison was the plodding experimenter, who made his discoveries through a physically iterative process in physical bench tests. Tesla was the ultimate theorist, with a capacity to thing through concepts fully, before placing pen to paper, or committing to experimentation. He constructed demonstration of light, electricity, and magnetics only after being sure in his own mind of the outcome.

Tesla brought the distribution of Alternating Current power to the world, and revolutionized industry and life as we know it today. He also brought advancement to lighting in the form of advancing fluorescent and metal gas discharge sources, at very near the same time that filament heating using direct current sources were being developed.

Unfortunately, while Tesla was a showman (he put on some amazing demos of light and electricity) he was not the publicity hound or marketer that other inventors of the era were. This set him up to be exploited by the likes of George Westinghouse, who essentially pushed Tesla aside to commercialize the AC inventions, without paying Tesla what was owed – which would have made Tesla the richest man in the world. Like the common crediting of the electric lamp to Edison,  Marconi is widely claimed to be the inventor of the radio and radio transmission. In fact, Tesla’s patent for radio transmission, awarded in 1897, predates Marconi’s improvement patents of 1903. However, using family connections and a flair for commercialization, Marconi prevailed in recognition, while Tesla remained in the background.

For anyone who interested in the fascinating period from 1800 to 1908, where the modern world was birthed on the inventors who turned us away from fire light and animal exploitation to the electric and machine age of industrialization, Nikola Tesla is someone worth investigating in detail. You will be surprised and amazed by his work, and his reclusive personality!

These links are to biographical information and additional reading and books on Telsa:

From Lucid Cafe
Drop Bears
Science World
Wiki Books
Tesla Society


Yes, Edison was a great inventor and contributor, but his position as sole inventor is a disservice to those who actually did invent the light bulbs we call incandescent today.

A little housecleaning here. I am re-posting this from one of my other blogs being cleaned out and deleted, from 2008. Thought it was worth keeping around, as this technology fades into history. KLW

While it is common folklore to credit Edison with the invention of the light bulb, the little heater-light source gadget we know as the incandescent lamp includes a long list of iterations and contributors:

1802 – Humphry Davy demonstrates first incandescence
1809 – Humphry Davy invents the first electric light, using carbon arc.
1820 – Warren De la Rue created the first vacuum lamp using platinum coil filament
1835 – James Bowman Lindsay demonstrates prototype light bulb
1840 – Warren de La Rue creates the lamp with coiled platinum filament
1845 – John Starr acquires patent for carbon filament incandescent lamp
1850 – Edward Shepard invented an incandescent arc lamp
1850 – Joseph Wilson Swan started working with carbonized paper filaments.
1851 – Jean Eugene Robert-Hudin demonstrates incandescent lamps
1854 – Henricg Globel, invented the first carbonized bamboo filament incandescent lamp.
1872 – A. N. Liodygin invents incandescent light bulb
1874 – A.N. Liodygin receives patent for incandescent lamp
1875 – Herman Sprengel invented the mercury vacuum pump to create vacuum lamps
1875 – Henry Woodward and Matthew Evans patented a lightbulb.
1878 – Sir Joseph Wilson Swan invents longer-lasting electic lightbulb using cotton carbon filament
1879 – Thomas Alva Edison invents a carbon filament in vacuum bulb
1880 – Edison improves his lightbulb using bamboo filament
, receives patent for “improved” lamp
1902 – Shelby bulb – A.A.Chaillet – long life using thick loose filament*
1903 – Willis Whitnew invented metal-coated carbon filament
1906 – Carl Schubel patents tungsten filaments (assigned to GE)
1910 – William David Coolidge invents improved process for making tungsten filaments

* 1902 entry added 10/2014 from input provided by Timothy Gravert and link to Chaillet biogrpahy.

There are many subjects in lighting, specifically in the universe of solid-state lighting, that need to be actively discussed and openly debated. Issues such as qualitative issues (color, color accuracy, glare, brightness, illuminance levels, etc..) over quantitative (lumens per watt), or the discussion of blue light content, or scotopic v. photopic, or supplier issues, or even the problems of being a small fish in a pond filled with big bloated corporate fish and a governmental agency who believes itself now a lighting expert… These all require active dialog to be resolved and grow understanding.  Too many times, the discussion of important topics are held in little rooms, hidden from view, with conclusions drawn, recommendations and regulations written – to be handed down like tablets from the mount, for us all to simply step in line and accept as fact. We have far too many instances of white paper writing scientists issuing their narrowly focused findings through their myopic peer groups, to be used as swords and weapons against the unwashed and unknowing masses. I find the creeping movement of lighting away from its roots as a human experience enhancing art-form into the hands of marketing zealots, narrow minded PhD’s working in their corporate labs, and federal or state agencies with agendas to follow outside our need to know… well, disheartening and disgusting. (more…)

The recent article: LED Bulb Efficiency Surges, But Light Quality Lags states very well the findings of the DOE and others reviewing LED retrofit lamp performance. While well stated, there are severl missing dynamic issues in the conversation that need to be included if LED is to overcome the failure of the CFL to capture the consumer market it so desperately seeks to dominate.

While efficient, there has been no great interest in the consumer market to lamps with poorer quality at higher prices.

While efficient, there has been no great interest in the consumer market to lamps with poorer quality at higher prices.

The CFL lamp has failed in the consumer market for these reasons:

  1. Light quality is poor in comparison to the far cheaper incandescent lamp. This includes color quality, distribution (photometric) pattern is poor (flood type products)
  2. Appearance and fit of the product into existing fixtures – i.e. ugly to look at, stick out of fixtures, create dark spots in shades and fixture diffusers, etc.
  3. They did not last as long as advertised. When switched frequently, the life of a CFL screw base product can be shorter than a long life incandescent. In outdoor cold climate environments, some fail within a few months. In down-lights and enclosed fixtures most fail even more quickly.
  4. They cost too much compared to incandescent of higher quality
  5. They save some energy, but have so many other liabilities the consumer does not take this seriously.
  6. Flickering starts, flicker under dimming, and 120Hz strobe effects from cheap ballast designs
  7. Slow to warm to full brightness – often taking longer to get up to full light than many products are on for in many rooms (pantry, closet, hallway, etc.)
  8. Mercury disposal concerns for some


08285I have a fondness for the halogen lamp. From the little 20W bi-pin 12V burners to the 500W double ended monsters, the combination of light quality, simplicity, toughness, light density and versatility filled a special place in the hearts of lighting designers for decades. While there were also  larger iterations of the technology reaching 20,000W, even the most halogen crazed found them to be a bit over the top, setting them aside for special applications. In my own experience, the 20W through 75W 12V burners, 15W through 65W MR16, 35 through 50W PAR36 and 75W through 250W mini-can line voltage lamps hit the spot for a wide range of focused and unfocused lighting product designs. For my personal portable lamp works, the low voltage burners, MR16 and the PAR36 lamps were my favorites. I could create live-structures (where the fixture acted as conductor) using remote 12V power supplies, allowing sculptures to be simple to the extreme.

This simple bridge design was created using building and armature wire, a PAR36 halogen lamp, and a ball bearing counter weight.

This simple bridge design was created using building and armature wire, a PAR36 halogen lamp, and a ball bearing counter weight.

When LEDs arrived on the scene in the late 1990’s, I caught a glimmer of what was to come. By the year 2002, it was obvious that solid-state would be delivering something new, and that the properties of the source technology shared a great deal with the halogen lamp from a lighting perspective, with a huge advantage – far less heat, much tougher and resistant to impact, and very long lived. The only issue was, color quality was initially poor, consistency from LED to LED was awful, and light output per individual LED device was pathetic. This required designs utilize a number of LEDs mounted to circuit boards, wired to drivers that were clumsy at best. The complexity of LEDs in the earlier stages were compounded by the lack of available components, which meant one-off application of the technology was out of reach for anyone not up for custom electronics design. (more…)

To set things off on the proper foot – I do not like complexity when it is not necessary. I’ve noted many times that if energy were free and maintenance was not a consideration, the perfect light source is the tungsten halogen lamp. This technology delivers a very attractive white light, is very easy to control, provides optical focus, and is as simple as it can get. The low voltage versions of this technology are equally attractive, accepting that transformers were a horrible thing to tag onto an otherwise neat little light source. I have made hundreds of lights using halogen lamps, mainly 12V versions, starting back in 1985. It was my go-to light source. I still have boxes of transformers and sockets, acquired over years of making lights for myself and others.

Applying LEDs in efficient lighting designs is no more complex than use of any other source, just more productive.

Applying LEDs in efficient lighting designs is no more complex than use of any other source, just more productive, and attractive than CFL or other conventional “efficiency” improving sources.

That said, there is no escaping that energy is an issue, and maintenance is a pain. The cost of operating halogen technologies is simply impossible to bear. This is why we have HID sources with all their ugly liabilities, and the fluorescent lamp.  While I get HID technology as a giant super-power halogen device, it has always been a clumsy, heavy, messy engineering gadget that sets aside the art of lighting for raw lumen energy. Fluorescent lamps have are a source you are forced to live with, in an uninspired, just-get-lumens-in -the-box sort of way. There is very little to love about their scale, lack of focus-ability, ballast hardware, delicate tubes, and ghastly glow. I’ve specified millions of these lamps into existence, wishing every time there was a better way. I never made a single art light using fluorescent lamps, not because itsn’t possible, but because I never liked them enough to give them that part of my time.

The emergence of solid-state lighting, specifically LEDs, hit me in two ways. One, I get the small controllable source I had with 12V halogen. Second, I get the efficiency and raw lumen potential of fluorescent that made it indispensable. Because of this, the last time I made a light using halogen technology was in 2004, and that product was converted to an LED sources in 2006. For my own use, every halogen light I made from 1993 to 2004 still in use around the house, has been converted to LED. Every new fixture made since 2005 has incorporated an LED light source, without exception. I do not use retrofit lamps. I either tear down and rebuild products to utilize LEDs properly, or design them around LEDs in the first place. (more…)