Tasca Test Mule Turns Two
The Tasca test mule turned 2 years in continual illuminated state this May. That’s 8,760 continuous operating hours in the cold, hot, and messy environment of the shop in which it lives. It gets abused as well, from tossing greasy rags over it to see what happens when airflow over the heat sink is cut off, to blowing coolant on it until it freezes. There have been several lessons learned in this time. For example, lumen depreciation, captured by measuring the fixture’s output, has been negligable. Losses have been less than 1.2% so far, which means the White Optics reflector and anti-reflective glass are doing their job, as is the Bridgelux ES Array LED. Temperature readings taken over this time have not changed anywhere, which indicates the internal construction attaching the thermal slug to the heat sink is durable and reliable.
While the Mule will remain in service without changes, the product line itself has been updated using lessons learned and incorporating the latest LEDs. The original product consumed just over 15W, delivering 620 lumens, for an efficacy of 41 lm/W when it won the PIA award in 2012. This has improved significantly in 2013, with the latest Bridgelux array, adjustments to the reflector design and updated driver from Recom. The current version now delivers 801 lumens using only 12.3W, for an efficacy of 65 lm/W. This is an increase in light output of 29%, while reducing energy consumption by 17%. In addition to these improvements, a new driver circuit board incorporates screw terminals, making it an easy to replace module should their be a need for maintenance. In fact, the entire product is modular. The head is easily removed from its arm for replacement or repair. The driver is now fully modular and field replaceable. The LED is pre-wired and now uses a GrafTech thermal interface pad, which improves thermal performance, and allows the LED to be serviced (replaced) without messy greases. The power supply – the most likely component to fail in any LED system, is a separate wall plug device connected with in-line DC connector, making replacement simple and fast.
Based on the test results and ongoing experience with the product, Tasca now comes with a 7 year warranty. This is not just for the normal “materials and workmanship” most offer. I am warranting that under normal operating conditions, the product will maintain 70% of its initial light output for a period of 36,000 hours, or 7 years (whichever occurs first). Between this warranty, tough construction, and the modular components, the Tasca work light is perhaps the first and only true long life LED product on the market. There is no reason this product cannot remain in service for decades.
I am an enthusiast for old machine shop equipment built in an era when durability and maintained longevity pre-dated today’s throw-away planned obsolescence. My specific goal with Tasca was to follow the traditional approach to engineering – built in toughness and long useful service life. I don’t follow or support the idea that a product should be discarded when the light inside becomes unusable. I believe in products built to last, testing to verify assumptions are correct, and backing what I make with a warranty that reflects the intended use of the product. Tasca Uno, the work light represented by the mule, is Tasca’s flagship, reflecting three years of continuous improvement and over two years testing.
Anyone interested in having one of these lights in their work space can find them on-line at Tasca where more detail can be found and links are provided for on-line purchasing.
Dimming to Warmer CCT’s – On Second Thought
When LEDs first emerged, I was one of the many who expressed the opinion that a lighting system that could dim to a warmer CCT, imitating incandescent lamps, would be desirable. I want to take this opportunity to retract that original opinion and thought. I’ve played with it, seen the products available that do it, and have experimented with the approach… and can say unequivocally that I really don’t like it at all.
One of the problems with incandescent dimming has always been the patchwork of CCTs one gets through a space from different dimmer settings for the various products in a room. This has never been a good thing. Further, the change in CCT of an old school incandescent lamp is significantly different than halogen lamps, as it the character of the color. I for one have fallen out of love with the old incandescent lamp long ago. Over the last 20 some-odd years, I have come to use halogen sources over all incandescent forms, preferring the cleaner white color over that yellowy dinginess of the incandescent lamp. Incandescent lamps (non-halogen) produce a decidedly ugly color that I personally feel is misrepresented by their high CRI rating. The fact that the CRI formula will show a dimmed incandescent lamp with the same high CRI number, even when it very noticeably distorts color in a space, is a condemnation of our poor color performance metrics, not an indication of this lamps superior color performance. (more…)
LED vs CFL – Game ON in Side-by-Side Comparison
Working with Molex Electronics, the ZEBRA Alliance, Oak Ridge National Labs, with fixtures provided by Ultralights and Solid State Luminaires, we created a side-by-side comparison between CFL and LED in two identical homes. One uses 100% CFL lighting, the other 100% LEDs. The LED house uses Molex Transcend modular products, which incorporate 4W Seoul Semiconductor Acriche 120VAC LEDs to control costs. While the CFL home was designed by a lighting showroom, the approach in the LED home included redressing lighting design to reduce and elliminate glare, focus on delivering light where it is needed, and producing more attractive spaces that also save energy. The end result is a 70%+ savings over the CFL home. The LED home has less than 0.4W/s.f. of connected lighting load. So little energy is connected, that the entire home could have been wired to a single 15A circuit breaker (920W).
The purpose of this project is to operate both homes with controls that simulate occupied operation over 18-24 months. Over that time the performance of the two homes will be monitored using a sophisticated array of sensors and data aquisition. Lighting is just one small part of the total effort, which includes building materials, HVAC, window glazing, and roofing system performance. There are four total homes, all with identical geographic orientation, within a block of one another. The other two utilize fluorescent lighting, but are different in many other ways, including architectural design.
Below are a few of the rooms of the houses to give you an idea of how the combined approach worked out. As one can see, the difference in appearance is noticeable. At the task level, the LED house provides twice the horizontal illumination on kitchen counters and dining table, matches the CFL in the game room and office (not shown here), and provides a more comfortable light everywhere, as the light sources produce no objectionable glare. So, regardless of the LED employed not being a leading edge lumen/watt producer, the savings remain significant, while the end product – delivered illumination – both attractive and comfortable. This is an approach that will eventually set LEDs up as the preferred light source in residential application – not matching CFL glare bombs, but delivering an improvement in lighted quality as well as energy saving.
For those attending the LEDs 2010 conference this month (Oct 25-27) in San Diego, I will be presenting this project with some background and more detail there. Stop by and say hello if you are in the area:
Molex and Bridgelux Take the Big Prize at LF2010!
The Molex Helieon module with Bridgelux array won the “Most Innovative Product” award, the highest honor one can achieve at Lightfair!
As a consultant to Molex on their entry into the SSL arena, specifically on the Transcend and Helieon projects, I can offer that the effort put into understanding the lighting market, and how SSL can be applied within it, has been impressive. Seeing them take the prize was a thrill for me personally, and certainly for the groups at both Molex and Bridgelux. Playing the role of “Lighting Guy” in this group of exceptional electronics and mechanical engineers, who tackle connector problems in everything from cars and consumer products to computers and spaceships, I’ve experienced a development pace unprecedented. The combination of optics, tactile feel, simplicity in application, and potential for further expansion of capabilities, the Helieon is just one more example of what a market leading connector manufacture can do for the lighting market.
In Architectural SSL we’ve continually pressed for modularity as an important and necessary component in the furthering of SSL deployment. In 2010, this appears to be the year for just such development. The Xicato, Cree’s introduction, Philips Fortimo, and GE, along with Sharp, and the GX53 socket for SSL by BJB, and the Helieon, all offer significant improvements in the way LEDs will be incorporated into products. On top of this, manufacturers, such as Solid State Luminaires, have incorporated modularity into the construction of their latest downlights and other products. Modules have finally arrived – with the Helieon taking top honors as the leader of the pack.
The snapshots below are from the show display, where Lumenique fixtures were used incorporating 45 Helieon modules used to illuminate the display.
52 in 52 – Week Two Kickoff
- Bent part – tip of vertical members
01/07/10 – And now for something completely different. Ever heard of Steam Punk? It’s a design vocabulary founded on Victorian styling blended with technology as it might have been had we not moved into micro-electronics. Time machine movies are excellent examples of the aesthetic. Applying this to an SSL product just seems too ironic not to do, so this will be the week two project. This one is going to use Bridgelux 400lm LED arrays as uplight and downlight, within a pivoting head. Driver will be from Luxdrive, and operated at 1A. Control is going to be via placing a plumb bob in one of three sockets, which will control the driver dim level. Finishes will be powder coat red, powder coat black, polished aluminum and polished brass. This one is mostly lathe turnings, my favorite tool.
01/11/10 - Got a lot of parts made and some details figured out. Had a bit of an issue with the ball turner, which decided to grab a part and bend it over on me. Really a pain since the ball is the last thing you turn after cutting the rest of the part. Had to re-invent the tool a little before I trashed another blank, then started all over to replace the bent part. Been making a few adjustments in detail as I go through each part – some to fit materials I have in stock and to improve detailing, since there is nothing quite like having the metail in hand to fine tune detail. Working the light heads now – a lot of stuff packed into a somewhat small space. Last bit to work out is the swivel so it will hold the head in place and not sag, but will be easy to adjust. So far so good. The Bridgelux LEDs put out so much soft light, this one should make a nice general space illuminator, with back/uplight and down/tasklight.
01/15/10 – Been a tough week, but the project is progressing. Just finished the base plates, have the vertical conductor towers ready to finish, have figured out how to make the controls work properly, and have the head 90% complete, just need a couple of holes drilled and everything is ready to finish. While the target is to finish each of these on Thursday or Friday of each week, projects like this one are abit more complex, so will take a day or two longer. By the end of the day today, everything on this will be in finishing, with assembly tommorrow (Saurday), just in time to startweek 3, which has already beed designed. This is going to be tough to keep up with, and requires I think clearly and not make any serious mistakes that eat time.
52 in 52 – Design One Complete
So… the first week went well enough. Even with taking time off for the holidays, working in a deep freeze workshop, and managing to mess up several blocks of metal, I managed to get this one done. I’m also breaking in a new powder coat oven and learning to use a couple of new tools, like a virbatory deburring machine that works away at the sharp corners and file marks while I get on with other work. Generally this one worked out about as I had invisioned, except for shortening the arm a little. I’m also thinkin that the next iteration of this will use finishes a little differently. I’ve created a matte white powder finish I really like the look and feel of, will need to find more places to use it. In any case, with this in the done file, its time for a couple days to regroup and get into the next one.
I’ve got an idea in mind for use of Bridgelux 400lm LEDs in a steam-punk looking design that will light up and down, providing good ambient as well as accent downlighting. Something a bit less edgy, maybe use a lot of lathe turned parts and do a little polishing. Might even use some brass I have on hand for just such a purpose.
52 in 52 Design One Specification Brief
24″ wide x 20″ tall
Lynk Labs 12W Snapbrite strip (12VAC) on SnapDriver power supply
Custom switch design and fabrication
Tumble finish aluminum with clear gloss topcoat, wrinkle black and matte white finishes
More images and details available at: D1 of 52 at Lumenique
Let me know what you think!
52 in 52 – Design One
12/30/09 – This is the first of 52 designs for the year. I thought about posting a drawing or rendering of the complete design at the start, but what is the fun in that? Instead, I’m including a few sneek preview details that will be included in the final design. To see what the finished product, both in-process and completed, you’ll just have to follow along, or wait a week. Design One is a fixed head architecturally styled task lamp for a desk or side table. It’s going to be around 20″ tall and extend 28″ horizontally. It will use a Lynklabs 12″ SnapBrite LED strip with 12 Tesla LEDs, powered by the companies BriteDriver 12VAC power supply, provided as samples to me by the company. This will deliver roughly 200fc onto the task surface. The finish will be black textured and matte white high reflectance powder coat (my own formulation), with satin and polished aluminum accents. I plan to get most of the rough cut parts machined this weekend, so stay tuned!
01/04/10 – All design, machining, and mock up of rough components completed. Ran into a little snag finding a proper switch, so made my own from a proximity control and Delrin block. Had to remake the block at the top of the main column three times due to the length of the drilling horizontally for the support rod which went in straight and came out off center. Also fussed with the length of the arm - cut hree inches off it to balance the appearance of the assembly. Man, is it cold in the garage where my machining equipment is. Had to take a couple days off due to temps in the single digits, which makes the oil so stiff the machines struggle. The rest of the process can be done in the sheet metal and assembly area, which is heated. Going to have to get a better heater in the machining area.
Design Is Key to Efficiency and Quality of Illumination
In response to a growing sentiment that “playful” design is doomed due to the demand to cut energy use, that we must give up quality to cut watts quantity. I could not disagree with this more. In fact design plays a much larger role in cutting energy use than anyone is, giving it credit for. In fact, I contend that design of an application plays a larger role than reaching for some ultimate efficiency number. The two renderings shown here were created in AGI32 using photometric data from available LED products. The effect of design on the quality of a space and its energy use are clearly illustrated. The only factor changed between these two renderings is the lighting system applied. All other factors are identical.

72Watts - This "efficient" design uses (6) 12W"high efficiency" luminares rated at 52 lumens per watt to meet the illuminance requirements necessary for the space - an average of 12 Fc throughout. Yet, there is not a lot of interest here - the space just looks flat. There is very little focus or dimensional definition beyond the physical objects themselves.

40 Watts - This space uses (10) 4W medium efficiency luminaires at 39 lumens per watt, but much narrower beam spreads. The result is lower average illuminance (5Fc) but greater definition of the space that reinforces vision within the 3D space. Further, there is more visual interest and a central focus. Best of all - there is a realized energy savings of 48%!
Don’t buy into the baloney that energy conservation requires one must eschew design. Instead embrace the use of artful application of light to reduce the amount of light being thrown into a space from luminaires with poor control but high efficiency – use less light, with greater focus onto target surfaces. The art of lighting design is about design for vision, not meeting prescribed illuminance levels on some plane above the finished floor. The best designs create the most interesting and visually attractive space with the least amount of energy. We do not want to live in a world where the only qualifier of efficiency is the luminaire manufacturers data sheet above all else. Not only will this lead to greater energy consumption, it will reduce the quality of space we all live within for no reason. We need more design, more interest in the application of light, and less influence of purely empirical calculation.
Design has been devalued by those who believe lighting is something to be applied to meet minimum standards, that “effect” is a luxury that we can live without. This is why we live in offices with uniform illumination levels and flat surface rendering that gives us all headaches and eye strain. We know we don’t like it, ut live withit it. Why? Dynamic vision is created as much from the design of dark releif within a space, as it is from applying light onto horizontal planes within a calculation tool. The difference in these renderings are subtle in 2 dimensional presentation. In the 3D space we all live within, the effect is far greater and more readily felt and seen. With a greater degree of design expertise, we can realize greater energy savings AND an improvement in visual performance and quality.
One Colorful Step at a Time

Now that the office is 100% LED, including a retrofit of the pendant, a retorift/remodel of a Kovac Feather task light to LEDs, and a custom copper tubing linear wall washer - all white now... its time to step up and get into this color thing head first.
I miss the simplicity of low voltage halogen lamps. Must be getting old… A lamp, socket, transformer, a few bits of shiny metal, a switch from anywhere, maybe a sliver of glass, a transformer, couple lengths of wire… clean and simple. LED projects are a bit more complex, especially when you want to incorporate color in the mix. I tried a few white only LED designs and found them… well, common and boring. I’ve retrofit most everything to LEDs, from decorative to work lighting using white LEDs, my office is 100% LED now, the house is now 75% LED, 20% CFL, and the remaining halogen lamps, soon to be disappeared in favor of new LED products of my own invention. This has all been fun, but the end result is not that much more than I had, short of the energy saving. This is not what I believe in, it’s just the easy way out.
So, the next step… (more…)
The Efficiency Thing – Why an Artist Would Care

With the variety and performance of LEDs, the opportunity to be creative with them is unbound... except for the heat thing.
LEDs bring a lot of creative potential to the lighting market. At this creative front will be artists who apply them in unique ways outside the mainstream general illumination marketplace. I’m one of them in fact. Gone are my days of fooling with halogen lamps and transformers – now its LEDs, drivers and power supplies… and heat sinks.
The first wall hit in application of LEDs is their output and thermal dynamic. In halogen lighting, the fixtures got hot, no big deal. As long as it wasn’t peeling flesh or raising a blister, its was fine. LEDs don’t work that way. Long before the lighting portion gets hot enough to raise a blister, the LED is fried, game over.
Ultimately, the goal of an artist in creating a new work of light is to generate as much light as possible in the smallest, most innocuous package. That makes LEDs at once attractive, and a problem. To illustrate, a 350mA 1W LED requires very little thermal management to survive. Glue or screw it to plate of aluminum or copper and its happy. Problem is, the amount of light is pretty weak, between 35 and 60 lumens if you want 3,000k color with good color rendering (yes, artists do care about color – a lot.) That’s a long way from the 600 to 800 lumens we were used to in halogen sources. Optimally, for a task light with a good optic (wide smooth beam), gettting to around 350 to 500 lumens is optimal. This means more energy. At 700mA, 100 lumens is attainable, and lands us in the 3 to 4 watt range. Three is always better than 10, so this sounds like the way to go. Problem is, a 3W LED is exponentially more demanding thermally than that 1W device. These higher energy devices demand heat sinks, real life thermal management, with airflow and everything. (more…)
























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