Archive for the ‘New Venture’ Category

Zero Flicker Task Light

Posted: January 21, 2016 in Light Meters, Tasca
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The Tasca task lighting head. My pet project for more than 6 years now.

The Tasca task lighting head. My pet project for over 6 years.


When I created Tasca, I had several goals in mind:

  • Strong light output  – Check – 800 lumens is top of its class
  • Smooth wide light pattern – Check – 78 degree beam pattern with no hot spots, no streaks, no rings, >200Fc at 18″
  • High color performance – Check >80CRIe standard @4000K, moving to >90CRIe @4000 or 5000K in latest models
  • No sparkly LED arrays – Check – single high quality COB array source
  • High efficiency – Check – >70lm/W total fixture efficacy
  • Tough and Ready – Check –  examples have been in operation 24/7/365 in shop environments with zero failures
  • ZERO FLICKER – Check – see below

During the development of Tasca, finding a flicker meter was a little tough, so I improvised an oscilloscope and photocell rig that allowed me to see light output modulation. Using this we experimented and tested combinations of LEDs, drivers, and power supplies. I felt the end result was pretty much spot on, as near to the zero flicker from battery operated sources or even daylight as one could get. Yet, until recently, I had not been able to verify this was the case. Enter the UPRtek MF250N flicker meter (review to follow soon). With this, I have finally been able to see how well the Tasca head was performing. I was thrilled with what we found.

The Target

Daylight and the DC LED ideal models to set a high bar.

Daylight and a DC powered LED were set up as our performance target. They simply don't flicker, so using the meter, I tested these bench marks.

Daylight (left) and a DC powered LED (right) were set up as our performance target. They simply don’t flicker, so using the meter, I tested these bench marks. Note that small aberrations in readings (like the frequency of 5 for daylight along with a frequency magnitude of 2.6, or the frequency magnitude of 0.6 with no frequency for DC connected LED), are just that. This happens in all metering to some degree, and are within a margin of error for this meter system.

The Tasca Head Result

The results speak for themselves.

This is Tasca

The results for the Tasca head are exactly what I’d expected. Their simply is no flicker. While the meter indicates a Flicker percent of 000.6, and a magnitude of 0.2,  there is no frequency component, so these are irrelevant.

I was thrilled with the results. It meant several things. First, these metered results were essentially identical to what we got with our shop made flicker measuring rig. Second, the product itself is simply doing exactly what I intended it to do, which is truly satisfying.

Comparisons for Fun and Perspective

As long as we had the meter out, I figured why not get a few more readings for comparison. The results:

This is a T12 on magnetic ballasts. The beast that started the flicker discussion.

This is a T12 on magnetic ballasts. The beast that started the flicker discussion. The wave form shows obvious modulation, supported by poor results in both flicker % and index. The height of the wave shape is evident in the VFMA (Flicker Amplitude) and FMag (Magnitude) readings as well.



LEDs connected to AC circuits are not a good thing, even this one using additional bits to supposedly reduce flicker. The results are the highest flicker % and Flicker index of any source in this comparison, in every measure.


Capacitor AC LED

This is an AC connected LED with big capacitors added in an attempt to fill the gaps. While it reduces the flicker index to some degree, it has no effect on the flicker %, while the odd wave form creates strange results in other areas.


This is a retrofit LED

This is a retrofit LED. In general, it does not do a bad job reducing flicker, but is obviously playing a trade off game between cost of driver/power supply and output modulation.



This T8 fluorescent with electronic ballast is doing a nice job of controlling modulation, with a very small, impossible to see modulation at the native 120Hz.

P.S. Notes on the Flicker Argument

I recognize that there is a grand debate about flicker and whether or not it is an issue at all. Most of the argument against setting strict flicker standards are put forth by those who seek to market low cost LED products that exhibit flicker of 120Hz, whether that be AC LED product based or just low end power supply components.

There is no case to be made that flicker is a positive component of lighting, and extensive past industry experience with T12 fluorescent lamps on magnetic ballasts, and HID sources used in commercial application, is what started and fueled the discussion of 120Hz flicker as an issue. Complaints of visible modulation, headache, migraine, etc.. have been studied and found to be corollary to  the existence of flicker. Further, studies have proven a connection between flicker below 200Hz having a negative effect on visual performance in schools. While it is true that organizations like NEMA, IES, CIE, and IEEE have yet to come to an agreement as to what defines bad flicker vs. acceptable flicker, this lack of agreement does not indicate there is no issue. In fact, that these organizations have and continue to discuss this issue, against the steady pressure of manufacturers to set it aside, is an indication that there is a very real issue with flicker, that will eventually be resolved – albeit with some compromise included to placate manufacturers involved in standards proceedings. As a member of the IEEE 1789 committee on the topic of the risks of flicker, I can attest to the depth in which this topic has been investigated and discussed, and bear witness to the hundreds of papers written on it and its effects on vision and human physiology.

In my own opinion and recommendations to others, I ask one question – If there are sources and products available that exhibit no flicker, or flicker of such character as to not be an issue (such as T8 and T5 fluorescent on electronic ballasts, and quality LED driven products), what is the reasoning for continuing to accept any products that flicker in the zone of 100Hz to 200Hz, with a flicker amplitude >0.3 (minimal modulation depth) at all? Any level that exceeds, approaches or shares flicker characteristics with the T12 fluorescent lamp on magnetic ballasts, in my opinion, should be considered unacceptable for any use, regardless of arguments over cost saving. This includes any continued use of magnetic ballasted HID sources for interior illumination and AC connected LEDs (with no flicker mitigation) – as these are all far worse than the T12 lamp.

While in ambient lighting, a weak case might be made that flicker may be of small consequence – I propose that in task illumination, where visual acuity is critical, focus is the goal, and high illuminance and task demands increase the risk of stress, there is no rational case to be made to accept flicker of any level. For this reason, I have focused my attention and effort on creating lighting systems (and sources for components) that present either no flicker at all, or characteristics, such as high frequency operation (>2,000Hz), very low modulation depth (amplitude of <0.3%), low flicker index (<0.05), at all light level settings or dim states. I believe these to be reasonable and attainable standards, and have found no reason to accept poorer performance.


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. (more…)

The Cat is Officially Out of the Bag!

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:

Tasca Web Link

We have also put several products up on the Lumenique Product Center for direct purcahse. These are semi-pre-configured products with popular options. You can choose one or dozens, we don’t mind.

Tasca at the Lumenique Product Center

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.

The Preview 

At ArchLED11, held in Chicago November 9-10, TASCA will be revealed publicly for the first time.

TASCA is a lighting professional based product focused on hard service task lighting. This is not the decorative foo-fah, designer pretty stuff that intends first to please the eye with elegant line and sexy physical execution of artistic design that just happens to put out a little light to justify their existence. Tasca focuses first on delivering high quality light on the task and work surface, of a color and level to improve visual performance. Unlike low power light emitting decorations, the smallest Tasca products delivers 210 Fc at a distance of 18″, lighting an area of 36″+ in a smooth light pattern free of harsh shadows. We deliver a unified single light source presence to eliminate the multi-dot dazzle and fun-house shadowing created by the typical multiple LED arrays found in lesser lighting products. Tasca optics control brightness to avoid discomfort glare, while delivering the efficiency, instant on, flicker free, low heat, high quality  light of solid-state technology that no conventional light source can hope to compete with, in a hard service package designed to withstand hard use for decades. Tasca intends to participate in putting an end to the era of inefficient heat of halogen and slow starting flicker and poor intensity of CFL work lighting.

There will be three executions of Tasca presented at the show:

TASCA UNO is the core product line, offering flexible goose-neck arms in a wide range of lengths and mechanical arm mounting, as well as direct mount, magnetic base mount, stand and bracket mounts. Uno offers customization of configurations to suit the exact mounting configuration needed to satisfy application needs. We’ll do customs as small as one-of requests to complete facility systems. Tasca Uno is designed as a modular system of light head, mounting arm and mount, allowing the customer to put the light where they need it with precision, rather than force a standard fits-all solution.

TASCA RENOVAR is industrial recycling at its best. We capture used mounting arms from classic task lights, like those from Swivelier and Dazor; vintage industrial products from South Bend and others that have been used for decades with incandescent, halogen, or fluorescent heads; and cherished favorites brought to us by customers. We renovate the arms, refinish them, and refit them to include the Tasca lighting head. The finished products deliver the best of all worlds. Recycling of components rather than disposal by integration of the latest LED technology, to deliver significantly improved lighting performance. Tasca Renovar will produce more than twice the illuminance at less than 1/3 the energy of any conventional light source.

TASCA ACCENT is a blend of Tasca lighting heads with more decorative finishes and mounting details. These can be founded on recycled components, or they can be completely custom to suit a specific desire. Tasca Accent is for those installations where there is a need for a little more focus on aesthetics is desired, without compromising lighting performance.

Tasca products are made in the USA, built to customer order. We are not a warehouse operation focused on shoving inventories purchased overseas into the market in volume. Our strength is in our ability to build a product that is specifically tailored to the needs of the customer. Tasca products utilize Bridgelux LEDs, and nothing but the highest quality modular electronic components available. The modular construction allows any potential failed component to be replaced independently producing decades of useful service. Tasca products are also rebuildable by returning them to the factory for quick turn around of refitting and renovation. We can even re-purpose products by refitting mounting components should application needs change.

For those in need of application assistance, we are here to serve. We can help in laying out a lighting strategy, application of task as well as general ambient illumination, to the design and  manufacturing of the mounting hardware required to execute a complete high productivity lighted environment. Our foundation is built on lighting design experience first, with a long history of interest in task level illumination. We are passionate about work lighting like none other in the solid-state lighting space.

This is just the tip of the iceberg for Tasca.

We will have 11 fixtures on display at ArchLED, booth #204. I will also be presenting a couple times and assisting with the show MC duties, so will not be hard to find.

Hope to see you there!

My absence for a few months here is the result of time taken to organize, expand operations at Lumenique, complete customer projects, and to put the final pieces together for an all new company – Tasca.  Over the last few years, I have sought to find a small place for myself as a product manufacturer within lighting, specifically in producing SSL products that deliver new value. After considerable effort and more than a years exploration, I have finally found what I was looking for. Here are the specific qualifiers I used:

  • Product must put LED light sources into service to deliver a value that is superior to other light sources – beyond simple energy savings
  • Product must capitalize on low heat, instant on, good optical control, lack of flicker, endurance to shock and vibration
  • Product application must be demanding and serve a need where lighting is important to the end use customer
  • Product line must deliver value at a reasonable price
  • Product line must include capabilities and new lighting effects that cannot be matched with conventional sources
  • Product line to be made to order, with significant domestic content
  • Product line is to be configurable to suit end use customer needs
  • Company focus must be outside the commodity mainstream and large corporate entity immediate interest at the time of initial launch
  • Company must be scalable, with controlled investment requirements, utilizing available technologies without over-investment in R&D for all new technology
  • Company must be profitable
All this said, I have a few specific personal interests, which should be obvious for anyone who’s followed the 52 in 52 project. While those products were unconstrained by marketability of any specific design, Tasca will offer only market ready, functional products for sale. However, there will be more than a few of the following components included in the products released within Tasca:
  • Industrial aesthetic
  • Solid and durable construction
  • Ease of use
  • Long service life with end-of-life rebuilding
  • Consultive sales assistance
  • Highly configurable and flexible for application in a wide range of uses
The name “Tasca” is revealing, and an indication of the companies focus, which is more than I will reveal at this moment. The first tooled component arrives this week, which will initiate the production of the first products in final form. Photometric testing has already been accomplished using prototypes, as has the initiation of cataloging, and the first stages in creating a new web site.
Want to know more? Stay tuned. I’d love to spill the beans now, but I need some more time to finish the product line and prep for its launch. Sharing too much now, in a market filled with knock offs and rip offs, is just not prudent. More will be released when its time!