The original idea for the lighted magnifier was for inspection and reading small print on tools, which are generally done in a fixed location. The intended use was for continuous periods of work that made battery operation an issue. Mainly, the initial thinking was to turn it on and leave it on for the duration of a project. So, with it in hand and in use, I found in a short time it was being used for much more than its original intent. The magnifier lens in its unlit state is excellent in capturing ambient light, so I had it in mind that one lighted unit for the very tight and difficult work was great, with an unlit version for all other tasks. Problem is, the lighted unit provides over 1,780 FC on the target, transmitting over 700 FC to the eye at 4″. The unlit version produces no more than ambient levels, and if your head shades the ambient light, that is cut considerably. So, when comparing the two in actual use, the lighted version simply knocks the stuffing out of the unlit one. This meant I needed to cut the umbilical and create a battery powered version.
Actually, this started as a rough lab test experiment applying thermal transfer pipes (copper pipes filled with water) to move heat from an LED platform to a simple back plane surface. The experiment included bending the pipes, soldering them using silver bearing solder, and operating the system at various angles to see the effect these had on performance. Somewhere along the line, an idea formed of making this into a wall piece, creating an industrial-chic, which led to adding a cut down reflector, and using the SLA printer to create an industrial tech representation of a flame rising from the reflector. The square cut in the diffuser aligns with the connected graphic on the back plane, and the stenciled number 15 simply represents the year.
The driver is housed in the FDM printed housing below the light source on the back plane, with a dimmer. Total power to the source is 19W, while the LED is 95CRI 3000K. Note that the overly red hue to the background, and slight magenta appearance of the white graphics are all issues with the camera dealing with the red-enhanced LED source, which creates high CRI, with a 90 R9 value, but in reality is a distortion of spectral power that the human eye does not readily see – but mid-range camera image sensor algorithms cannot accommodate.
I found this little light on ebay at a lunch money price, so couldn’t resist. It started life as a Hamilton Industries (Chicago) lamp model 60, made in Japan in the early 1960’s. It used a 12V magnetic transformer and a resister to provide a dual level light control of its 20W signal lamp. The amount of light it put out was barely visible in the presence of any ambient light. Meanwhile, I had a cute little key-chain wireless remote controller for less than $14 from LED Supply that delivers PWM dimming and on-off control of 12VDC LED loads. I stripped the guts out of their kit and put them inside the base of the fixture. The little lighting head was about the right size for a 12V MR16 lamp, so rather than re-invent that wheel, I just retrofitted the head to take a bi-pin socket and planned to use a retrofit MR16 lamp to deliver the light I wanted. That ended up more of an issue than I expected. First, after testing of all the LED MR’s I had around, only one brand would operate and dim effectively when run on DC power. The rest were poor dimming on AC power, but on DC they were miserable. On the LED Supply remote dimming module, they were useless. The lamp I ended up with was a Philips Enduraled product, and it will dim down to around 10%.
The remote control is a bit of fun, as it has an antenna that works well with the antenna arm on the fixture, so they seemed a great match. I printed a holder for the face of the power supply (now control) enclosure at the base of the fixture to hold the remote, which makes it a simple panel controller when the remote feature is not needed. When the light is used to wash a wall or light art or some other function besides a desk lamp, the remote can be removed and control the fixture from across the room. The power supply is a simple 12VDC wall wart, while the base houses only the remote control electronics now.
The base looked in need of a bit of dressing up, so I printed a retro-turbo trim ring to surround the remote control mount on the SLA printer and painted it with VHT fake chrome to give it a sand-cast aluminum look. I also printed the same part on the FDM printer for comparison. I’m throwing in two images of the raw prints to show the difference in surface quality one gets between these machines. Obviously, for parts that include details that will be hard to sand and fill, the SLA process is superior. For parts that need to be strong and can be easily finished, the FDM is the go-to tool.
So, this little weak black egg ebay find has been transformed from a barely functional desk lamp novelty, to a bright, useful, remote controllable, dimmable, black egg turbo trimmed LED light novelty. I’m a fan of the 50’s and 60’s design aesthetic, so this one felt right and was fun to put together.
While not particularly visible to everyone in the SSL universe, over the past few years one area of interest in LED product development for me has been in use of 405nm LED light sources to cure various plastics materials. The advantages are lower power requirements and reduced overall heat in the cure zone over conventional fluorescent or HID light sources. This has been of particular interest in curing fiberglass resins manufactured by Sunrez. The typical demand is for between 200 and 1,000 µW/CM² at 400-405nm wavelength. The use of LEDs allows us to generate exactly that without the waste of visible light, and longer wavelength power the resins are not reacting to. In one project, we were able to replace a 1,500W HID light source with a 120W LED light system that produced faster cure times with less than 10% of the total power, and virtually no heat added to the heat generated by the resin’s exothermic reaction to the curing initiator. Since then, we’ve built 405nm light cure fixtures ranging from 1,200W to 25W.
In this case, I needed to cure 3D prints we generate on a Form Labs 1+ 3D SLA printer, and do so in an office environment without exposing other materials and occupants to UVA light output. The material used in the print process is acrylic based, with chemistry that is photo-reactive to 405nm. The actual prints are made using a UV laser source. When the part is removed from the printer it is washed in alcohol (91% IPA), rested for a few hours to dry the alcohol off, then placed in this cure cube for an hour or more, depending on the thickness of the final component. The end result is a hard first surface for finish sanding or painting, if necessary, and a more rigid part as a whole (less flexible).
The cube utilizes a simple aluminum housing, with FDM 3D printed top and bottom covers. The top cover houses a single Recom 500mA driver, slide switch and wiring terminal block on a Tasca LED driver circuit board.
5mm 450nm LEDs with a FWHM distribution of 60º, 25 per side and top (125 total), operating at 20mA each, mounted to custom circuit boards sourced at Express PCB. Each board connects the LEDs in parallel, while the boards are connected in series, resulting in a 500mA, 15.4V circuit, totaling 7.7W. The boards and internal exposed surfaces inside the box were then covered with White Optics 98 matte material to increase total light energy and diffuse The light energy at 405nm is roughly 600 µW/CM².
The bottom surface includes a glass plate where the product sits in order to make any possible stickiness of a part from adhering to the White Optic material below.
The housing was powder coated matte black polyester to make clean up easy and the box look nice. The overall interior dimensions of the box are 1″ larger than the total build volume capacity of the printer itself (5 x 5 x 6.5), as any over-sizing is unnecessary. This produces an optimal match between the location of the LED sources and any part the printer can produce.
The Cube is powered by a remote plug mounted 24VDC power converter.
The operation of the box is simple enough. The box is lifted up, the part is set on the base, the box is set over the part, and the light is turned on by sliding the switch to the on position.
Simple and compact is the order of desktop manufacturing, and this fits that model perfectly.
Testing so far has shown the cube can cure raw resin from liquid to fully hardened in less than an hour, and strengthens prints in that time or less. The heat generated from this arrangement is so small, there is no chance of any part being warped or affected by the process, other than the desired results of becoming stronger.
For parts to be left unfinished, that are desired to be used over extended periods, we coat the finished parts in either acrylic or polyurethane UV inhibiting clear coat, gloss or matte. This stops ambient room light or daylight exposure from making the parts brittle over time. I am building a second copy of this cube for completing extended testing of samples of the materials we are using to verify clear coat effectiveness, behavior of the print material over long exposure periods, and the behavior of these low cost LEDs over time. A commercial version of this cube could be made using more robust LEDs, but the costs would be significantly higher as well. In the current configuration, the LEDs only cost $0.60 each, so should they last a couple of years in use, replacement of the populated boards is a simple task, while the cost of higher power LEDs would have increased the cost of the entire end-product by as much as three times.
There is also an additional version of this same approach in using Red/Blue light sources for use in plant seedling starts. We’ve found tests with common rye and barley grasses, the time from germination to hearty growth ready for planting is accelerated significantly. Using an enclosure like this allows the plants to be exposed to intense light for extended periods of time (18 hours or more) without polluting the surrounding environment with the ugly light, just as the enclosed cube protects room occupants from exposure the the UVA light. In either case, the cube can be used in any room environment comfortably and safely.
So this gets us off the ground and is D1 of 52 in the series. As I’ve noted at the start, this is an exercise in making progress, and putting SSL to work. This is not a particularly exciting product in and of itself, but it is one that will be used regularly, which more than makes up for its lack of marketing sizzle for the masses – at least in my book.
The coming of spring demands a great deal of concentration when you live in an area that is frozen half the year. For April and May this has meant new projects progressing, outside interests fighting for attention, and the progression of older projects resulting in resolution of old issues. Unfortunately, due to the fact that there are those who feel it is their right to knock off ideas they find from others without attribution or recognition, I am struggling with how to proceed with this effort going forward. I enjoy exploring new ideas and sharing discoveries. I despise finding the results integrated into others offerings without so much as a nod to its source.
That said, for this installment of the 12 in 12 project, I focused on making progress in development of portable light originally introduced in the 52 in 52 project in 2010, and a spring project that is personal and fun.
The Battery Project
In week 4 of the 52 in 52 project, I presented this combination table torch/flashlight. At the time, I relied on lead acid emergency light batteries in an effort to create a reliable light for emergency use, using readily available components. Unfortunately, since then, I have found the approach flawed. The batteries were not reliable when connected in series to generate 12VDC, the charging components were not able to keep the batteries conditioned, and the discharge characteristic of the batteries produced an unacceptably short on-time when removed from the stand. Further, the batteries were far too heavy to be practical, and were expensive. Continue reading “An Update and a Mod”
The Test Mule passes 12 months in continuous operation.
In the process of building Tasca, there has been numerous iterations, prototypes in metal and plastic, tests to failure, drop and impact tests, electrical and electronic tests, and lighting application tests. As we found what worked, and what didn’t, and collected tooling for components, like the heat sink, I build the first functional products, using production level components. The first one made was what we affectionately call the Mule. It has been lighted 24/7 for one year as of the end of March, or a total of 8,841 logged hours to date. In that time it has been tested under operating conditions, attached to the side of a milling machine head, sprayed with lubricating and cleaning fluids, dropped, dunked, draped with rags under high ambient conditions, and frozen. As shown in the images here, this head has had a few hoods and shields attached to test effectiveness, and the mounting adapter has been changed a couple of times as I’ve experimented with the machined attachment hardware. This head has a thermocouple lead installed, so at any time I can plug it in to see what the temperature of the LED is, while there has been numerous output tests to check lumen depreciation, which has been less than 1% to date, right on track with the LM80 data for the LED (Bridgelux ES array).
This fixture has also been used as a baseline for testing the finished product as it has evolved. For example, we found that black anodizing og the heat sink lowered the LED temperature under identical operating conditions by as much as 10°C. We have also evolved the use of spring washers in the hinge, made small adjustments in the use of fasteners, and added the disconnect power connection to replace the Heyco cord entry – all found from actively working with the product and improving every detail. Continue reading “Tasca Uno Test Mule Birthday”
I thought a lot about what to focus on in 2012 for this series, and decided that I had plenty to share from regular activities of Lumenique, LLC and Tasca. So, the plan is to select something completed in each of the 12 months of 2012 and feature them here. This will generally be products or projects completed for customers, but may also include a report on research work in process, when it adds value.
January Feature – TASCA Renovar Floor Lamp
This is a refitting of a Dazor table lamp, applying the TASCA lighting head, and adding an extension stand to convert a desk lamp to a floor lamp. The product was commissioned by a customer who provided the table lamp, purchased used. From the GSA and other government markings present on the original, it was obviously from a government facility. The table lamp made by Dazor has been around since the late 1930’s, where the fluorescent lamp version graced the GE display at the Worlds Fair.
ArchLED’11 will be marked as the official coming out for Tasca, my work lighting product offering. We presented examples of the base Uno line, as well as several Renovar and one Accent light. If you are wondering what these are, and are curious to learn more, you can visit the Tasca web site now. The sitre is fully populated with pictures and a specification download at:
While I do not intend to make this blog a commercial site promoting products and pitching our offerings, I do need to make a living, so there will be occasional updates to share where we are and what we are doing in this regard. This is how we pay for the fun side of being in the business, and afford the time to invest and share with others information on solid-state lighting.
A Little More on Tasca
Tasca is primarily focused on the work environment. Whether this is a machine operation, an assembly work station, an inspection station, or administration workplace, my intent is to offer the most effective light for enhancing visual performance with a durable product. I’ve invested decades experimenting with task lighting. My personal approach has been to lower ambient surrounding light levels to the minimum required to support the low acuity activities in the space, supplemented by localized task lighting to enhance visual performance in critical work areas. I have applied this in lighting designs over the last 30 years to reduce energy consumption, and live under it on a daily basis. In other words, I am passionate about this approach and believe it is a superior approach to achieve high visual performance. I strongly believe we are over-lighting our work spaces to some compromised light level, which is too high for ambient requirements and too low for effective task performance.
Over the last few years, the idea of creating a work light for hard service environments, bringing the advantages of SSL technology to work spaces that require high visual performance to support safe, accurate, and efficient work tasks. For over a year now I have been investing considerable time building a product I feel satisfies the demands of work environments, with an efficient product that will survive harsh environments. Tasca is the product of this effort, and just the beginning of a larger effort to produce desirable performance SSL lighting products for niche work space demands. We’ve already provided customized versions of Tasca for UV curing applications, and will be releasing specialty products, such as a 98CRI sourced heads for color critical inspection (like printing presses, millwork, textile and paint inspection), as well as a unique welding light that will bring welders vision of their welding field that has never been possible before.
Tasca is also founded on the concept of sustainability from durable products that are recycled either by dismantling, rebuilding, or re-purposing at the end of service life, not just thrown away. Unlike products that are filled with potting materials and irreversible assembly techniques that make recycling too expensive to be practical, Tasca fixtures are heavy duty assemblies designed to be reworked, rebuilt, or dismantled easily for recycling of materials content, separate of the electronics components that must go through a separate recycling channel. This includes the use of glass for the lens cover, which can survive decades of use, or be recycled easily through existing waste management channels economically. The Renovar and Accent line take all of this one step further by harvesting old task lights for their arms, refinishing the devices, recycling the old lighting heads, and converting them to Tasca lights by adapting our lighting heads, before a complete refinish and refurbishing.We will also refit your existing task lights, bringing old favorites back to life by bringing them up to date, or through Accent, create a custom design to suit your specific taste.
This is just the start of a great deal more to come. Sort of pulling the plug out of a dyke and letting things flow. This is an exciting niche opportunity for me, where I can add value through design integration assistance, and provide customization to suit unique customer needs. Unlike imports which must be marketed in large batches of off-shelf products to move production inventories – Tasca is made here in the USA, to order, to meet individual customer needs – even if that means building something completely new and unique that has a total customer market of one.
There are many things I keep around me for perspective, my way of keeping time. I find the passing of technologies interesting, and attempt to understand how the transformations came about, and where they add real value – and where they don’t. For example, I have this great little carboard calculator issued by GE (dated 1973.) It describes incandescent lamp bases on the front, and shapes on the back, with instructions on identification of lamps by model numbering. Note that there is no reference to the MR16 lamp or base, as this was not yet in the market. Inside this little gem is a calculator that shows the impact of operating voltage on light output, power use and lamp life. I used this in customer presentations for years, as well as calculating dimming effects of light output and lamp longevity. So, today this is nothing more than a relic, a novelty from the past. CFL and now SSL is rapidly putting the lamps involved out of the market, and the government is aligned for the kill shot.
Another item I have in my care is a GE Model DW-48 light meter, this one a 1940 model. It has a dual purpose. It reads footcandles for general illumination use, and provides F stop data for photographers. This was left to me by my father when he passed, and remains a favorite of my lighting instruments. Interestingly, this meter reads LED light levels just fine. Unlike some of the modern meters I have, this meter remains within a 5%+/- range of true readings. I recently purchased an Amprobe LM-200LED meter for a field device after discovering other meters were giving me odd readings. The Amprobe device is really good for the $100 asking price, and provides reading in line with what I see using a full blown sprectroradiometer. So does the DW-48, reading virtually the same as my Amprobe, and with less variability than my Minolta T10M and Testo meters. I also like the deco styling, metal and glass enclosure. However, its not very useful in low light conditions, as the meter face is not illuminated and black, making it more a curiosity than a functional meter for daily use. Besides, if it gets damaged, it would break my heart, since it is more than a meter to me personally. As we rush into the future of lighting, I can’t help but smile at the thought that one day we will look back at what we have in our hands today and feel nostalgic at its crudeness and simplicity. We are heading into a bold new future, that will be obsolete at a rate that will embarrass all prior technologies that have swept through this industry. Just look at one of the original K series LEDs mounted on a star board – it’s got nostalgia written all over it! I have bins full of LEDs, drivers, power supplies and circuit boards that are so far out of date (made just 5 years ago BTW) that I can’t see using them on anything, regardless of their expense. I can get more for so much less today.
For the real cynics out there (I be one), I find it truly entertaining when I am exposed to the myopia of techno-philes now in SSL, who actually believe that LEDs are the ultimate end-all to general illumination. The future is not that predictable. We can be certain of but one thing – that there is someone out there today or in the near future, with ideas beyond LEDs as we know them, that will eclipse what we are able to imagine today.