LED vs Halogen

I had to replace some 50W GU10 halogen bulbs. I though it could be time to check if it would be reasonable to go to use LED bulbs. I did a year or so similar checking, and at this time it did not feel reasonable because reasonably prices LED bulbs gave considerably less lights out than the original bulb and the only few that would nearly match the original light output were very expensive.

Nowadays the market seems have updated to a point where LED seems to be reasonable. There is wide variety of reasonably priced LED light bulbs on the market. And it seems to be possible to find reasonably priced bulb that gives out around same amount of light as the original 40-50W halogen bulb. But I need to understand the specifications that I really get what I want.

Look at the Lumen value when you’re buying a bulb. The higher the rating the brighter the light! A standard 50W halogen lamp outputs 400 lumens so you probably need a 4-5W LED bulb with very efficient LED. With some slightly less efficent LEDS 7 or 10 watt LED will give a similar light to a 50 watt halogen. But just looking at the watts on the LED bulbs does not tell the light output because different LED types have different light output at same input power. Look at the Lumen output the LED bulb gives.

It is possible to get same amount of light than with original halogen if you pick right product. Here is a video that shows that Dauer 5W Cree XPE Chip Based GU10 lamp can give out 20% MORE light than does the 50W Halogen lamp (and uses just tenth of energy):

Besides the Lumen you need to consider other factors like light color temperature and other bulb design details. For LED lamps there are color temperatures typically named “warm white” (~3000K) and “cool white” (~5000K). Generally  “warm white” is what is what you need for normal home use. “Cool white” is very white in color. There are no absolute rules – the choice is about personal preference and use. If you like the traditional yellowish colour of a conventional lamp then warm white around (2700-3000K ) would be the ideal choice, this is the most popular choice for homes. For modern clean look with bright feeling you might also consider a cool white lamp (4000-5000K). Cool white could also be reasonable choice for kitchen, study, bathroom, cupboard, office, retail.

There is also difference in how the constant the light output on different LED light bulbs is. Some LED bulbs give pretty constant light outputs, and the light from some LED bulbs can flicker considerably. If you are sensitive to flickering lights, this may be important information to you before you spend a lot of money on them.

Check also the lamp design, different LED bulbs will look pretty different outside. There can also be difference on the beam shape they give (how wide beam) and how well the light shows different colors (color rendering). Go into a wholesaler and ask if they have a display of different lamps. LED light output will always look a little different than original halogen bulb: No LED lamp will have the same ‘sparkle’ as halogen.

If your light system uses light dimmer, you need to also check that the LED light bulb you are selecting supports light dimming. Many LED light bulbs are not designed to be dimmed and some designed to be dimmed might not work with all light dimmers.

Finally keep in mind the safety issues. Buy good quality bulbs that do not cause electrical hazards or interference problems. A bad quality LED bulb can cause electrical shock to you in a way or another.

It is also possible that bad electronics inside bulb can start fire. So get LED bulbs with well built electronics. A well built LED bulb is safer against fires because LED lamps have in all parts very much lower temperatures than halogen bulb (very hot halogen bulb is a real fire hazard if not properly installed).

Here is a video on selecting LED bulb to replace a GU10 Halogen Spot:

Now you have information to make your own informed choices on LED lighthing. With this information I was ready to go to shopping LEDs to replace halogen bulbs.


  1. Tomi Engdahl says:

    Fine Art Glories in Fine Light Resulting from LED Upgrade

    Few places warrant as much attention to lighting as a gallery or museum. The art has to look great or people won’t come to see it. So when the staff at the Minneapolis Institute of Arts starting wondering if it was time to consider LED lighting to replace the halogens in the galleries, it caused a stir. “Some of our colleagues were reluctant about using LEDs at their desks, so you can imagine how skeptical they were about using them in the galleries,” says Shawn McCann, MIA’s mechanical maintenance and utility specialist. “But we knew from using LEDs in our exit signs and elsewhere that we could be saving money with more efficient bulbs, so we wanted to explore it.”

    “At the time, LED lighting was still developing so it was hard to guide them toward a good solution,” says Sara Terrell, Xcel Energy account manager. “You hate to tell people to wait on their efficiency plans, but that’s what we decided to do until a better solution came along.”

    The process was a long one but was well worth their time and energy. “Now that we’re saving $149,000 a year in electric bills, it’s easy to say we did the right thing,” says Karl Shapansky, MIA lighting designer and technician. “But at the time it was hard to go through the process of testing various bulbs in several applications and locations.”

    New Lights, New Look

    Before making the purchase, the lights were tested in a few galleries. The new light made the art look fantastic, but that’s when they noticed the paint problem. The light gave the walls a yellow and purple cast. The installation was halted while the search for a new paint began. “It added to the length of the project but we had to fix it,” says Shapansky.

    With over 5,000 lights in its 140-plus galleries, the process of changing to the new LED PAR38 and PAR30 lamps took a long time. The team would remove the art from one gallery, install the lights, paint the walls, and replace the art. After two major phases spanning almost two years, it was done.

    “The new lights improve the depth of the artwork, making it look crisp and detailed, especially bringing out greens, blues and purples,” says Charles Walbridge, MIA photographer and Green Team leader. “The lights combined with the neutral, warm, gray paint really make the art stand out.”

    The museum itself is now a standout. The Minneapolis Institute of Arts is the first museum of its size to have 100 percent LED lighting in its galleries.

    “People either love it or have no idea we made the change,” says Shapansky. “I love it because the art looks great, but also because I can spend more time designing and less time up on the lift changing bulbs.” Shapansky used to replace 35 to 40 bulbs a week. The new LEDs should last five to eight years, or 22 times longer than halogens.

  2. Tomi Engdahl says:

    Cree’s new LED is an incandescent look-alike (pictures)

    Cree was able to get rid of the bulky heat sinks altogether by incorporating a convection-based design that vents out hot air and replaces it with cooler ambient air.

    Cree’s new bulb is omnidirectional, meaning it puts out light evenly in all directions.

    Cree’s 4Flow LED dims down to 5.6 percent brightness, and does so without buzzing or flickering.

  3. Tomi Engdahl says:

    California shines a light on LED lamp efficiency opportunities

    A few weeks ago, I attended a Title 20 stakeholder meeting at the California Energy Commission (CEC) headquarters in Sacramento. The meeting’s purpose was to discuss a Staff Report draft describing efficiency opportunities and proposing regulations for small diameter directional lamps and general service LED lamps. The report will form the basis for proposed amendments to the state’s mandatory Title 20 Appliance Efficiency Regulations.

    The first part of the 80+ page report focuses on small diameter directional lamps. These lamps are typically found in retail, residential and museum applications, using low efficiency incandescent or halogen technology. (High efficiency LED replacement lamps have just recently started to become available.) The proposed regulation requires small diameter directional lamps to have an efficacy of ≥80 lumens per watt (lpw), a minimum power factor of 0.9, and a minimum lifetime of 25,000 hours, starting in January 2018.

    The second part of the report covers general service “white light” LED lamps with E12, E17, E26, and GU-24 bases, including omni-directional, directional, and decorative product.

    To be compliant, a lamp’s CCT must be ≤3,000 oK. Two tiers of implementation are proposed.

  4. Tomi Engdahl says:

    LED Retrofit

    LED Retrofit: Most of the lamps I have purchased from ebay from China and Hong Kong for just over £1.00 each to £4.00 each. Don’t get ripped off paying £30.00 each from expensive retailers. LED 50w ballast from B&Q at £8.00

  5. Tomi Engdahl says:

    What…You’re Using Lasers for Area Heating?

    Come warm your hands by the laser beam? An array of tiny VCSELs can be used as a high-density, controllable heat source.

    But using lasers for area heating seems to be a contrary to their virtues.

    That’s why I was surprised when I saw the story on the benefits of “photonic” heating in Laser Focus World, “High-power VCSEL arrays make ideal industrial heating systems.” By setting up an array of hundreds of vertical-cavity surface-emitting lasers (shown below), you not only obviously get a different source of heat, but you attain some other unique operating advantages that are non-obvious and beneficial. Yes, the author’s company (Photonics Aachen, part of Philips Photonics) makes this system and so he is somewhat biased, but nonetheless, it’s worth seeing what he has to say.

    In contrast to conventional edge-emitting laser diodes, the collection of vertical-emitting laser diodes (each with a diameter of 30-40 μmeter) can be fabricated in one pass of wafer processing, including test, with about 500 VCSELs per mm2 of a die. Since each laser emits 1 to 10 mW, a 2 × 2 mm chip array holding 2,000 VCSELs can emit over 20 W of infrared power — that’s impressive power density for this technology.

    All this is impressive, but why bother when you can use standard halogen lamps, for example, to get the IR heating? First, the VCSEL IR brightness is 100 to 1,000 greater than halogens, with a lifetime of over than 10,000 hours, the author says

    The VCSEL array can be switched on and off in milliseconds for precise dosing control, since it does not have the thermal lag of a halogen emitter or similar sources.

    VCSEL array is well suited to highly targeted, localized zones, where the material to be heated may not be homogenous

  6. Tomi Engdahl says:

    More than 10 billion LED lamps

    Research Institute under the old connectors (incandescent and fluorescent lamps) lamps purchased 15 per cent of the LED based ​​last year. By 2023 the proportion will increase to 74 per cent, that is, the growth potential of LED lamps is huge.

    Led light market is expected to grow this year to 25.7 billion US dollars. Trend Force, one in four LED lamps sold in Europe. China’s market share is 21 per cent.

    According Navigant Research LED based on the lighting of the total deliveries in 2014-2023 will be 10.7 billion the lamp.

    Source: http://www.etn.fi/index.php?option=com_content&view=article&id=2432:yli-10-miljardia-ledilamppua&catid=13&Itemid=101

  7. Tomi Engdahl says:

    Tougher Light Bulb Efficiency/Performance Requirements for the U.S.?

    The future could get brighter using less power for U.S. consumers if the Department of Energy (DOE) decides to pass tougher General Service Lamp (GSL) standards. The DOE is directed by law to evaluate efficiency standards for GSLs and publish a final ruling by January 1, 2017. The department recently held a public meeting to discuss their preliminary analysis results.

    GSLs include general service incandescent lamps (GSILs), compact fluorescent lamps (CFLs), general service light-emitting diode (LED) lamps, and organic light-emitting diode (OLED)* lamps. The lamps covered by the DOE’s study are those that that utilize a medium screw or GU24 ANSI base, serve general lighting applications, are not integrated into a light fixture, and have a light output of at least 310 lumens. (A maximum output limit of 2600 lumens is currently being proposed.)

  8. Tomi Engdahl says:

    New Crop of LED Filament Bulbs Look Almost Exactly Like Incandescents

    Novel LED packaging adds filaments to retro bulbs

    I first saw these filament-type LED components in a candelabra-base bulb at the 2011 LightFair, and the company exhibiting it didn’t want me to take a photo of it. This year they were all over LightFair, although I’ve yet to see them for sale at a retail store in the US.

    The most common use of the filaments is in retro-style bulbs: clear bulbs that allow the “filaments” to be seen. These look particularly good in flame-tip chandelier bulbs. While the look may appeal to many as a throw-back to old-style incandescent bulbs, a practical advantage of the filaments is that the LEDs can be elevated for omnidirectional light, the same as an incandescent bulb.

    And beyond their similarity to old-school filaments, it’s a novel and interesting packaging and mounting of LEDs.

    Z-Light is unique in that it’s the only vendor that also offers the filaments themselves: Here’s a link to a PDF of an LED filament spec sheet.

    So how are LED filaments made? Here’s my understanding: The “filament” consists of relatively low-power LED chips (that is, unpackaged LED dice) mounted on a thin narrow glass (or transparent ceramic or sapphire) substrate. The LED chips are either joined by a metal trace, or jump-wire-bonded in series. Each end of the filament has a metal end for further assembly.

    The filament is encapsulated in a resin made up of silicone and phosphor mixture that performs the usual transformation of the LED chips’ blue light into white. In addition, the filament can be ordered with some red LED chips to warm up the light spectrum.

    With each filament capable of 1W, and assuming 20 LEDs/filament, it appears that the filament is a high-voltage, low current package. It also appears that the bulbs have an inert gas inside to help with the heat dissipation. The efficacy is as high as 130 lm/W at the filament level, but more like 100 lm/W at the bulb level. I’ve heard of pricing as low as $3 for a 6-filament bulb.

    Typical dimensions are 38.5mm x 2.0mm

  9. Tomi Engdahl says:

    Light bulb buying guide

    With strict new standards, the landscape of lighting is rapidly changing. Here’s everything you’ll need to know to keep up.

    When Congress passed the Energy Independence and Security Act of 2007 (EISA), the incandescent bulb’s days officially became numbered.

    Like it or not, the arrival of this new era means that replacing your lights will never be quite the same. With all of the new options out there (not to mention the disappearance of some important old ones), finding the perfect bulb can seem pretty daunting. New lights that promise to last 20 years and save you hundreds of dollars might sound good in theory, but how do you know which one is the right one for you? How do you know the bulb you’re buying is going to be bright enough? And what if you’re just not ready to say goodbye to your incandescents?

    We’ve all gotten to know incandescents quite well over the past 135 years or so, but times are changing. These days, you’ve got some new lighting categories to familiarize yourself with, and doing so is the first, most obvious step toward buying the right bulb.

    Light-emitting diodes, or LEDs, are the new rock stars of the bulb world.

    Before LEDs exploded into the lighting scene, compact fluorescent lights (CFLs to you and me) were seen by many as the heir apparent to incandescent lighting.
    many people weren’t thrilled at the idea of switching over.

    Aren’t incandescents banned?
    As a matter of fact, they aren’t. EISA doesn’t actually ban anything, at least not directly. What EISA does do is raise efficiency standards
    It’s true that traditional incandescents unable to keep up with the times will be phased out. However, the door is still wide open for non-traditional incandescents to take their place, and we’re already seeing some manufacturers rise to the challenge

    Halogens are just incandescent bulbs with a bit of halogen gas trapped inside with the filament.
    Due to their relative similarity to classic incandescents — both in light quality and in cost — halogens can work as a good compromise bulb for consumers who need to replace their incandescents, but who also aren’t ready to commit to CFLs or LEDs quite yet.


    If you’re buying a bulb these days, you’ll be left in the dark if you don’t know what a lumen is.
    Relying on these wattage equivalencies can lead you to buy a bulb that ends up being far too dim or too bright for your needs

    Replacing a 40W bulb: look for at least 450 lumens
    Replacing a 60W bulb: look for at least 800 lumens
    Replacing a 75W bulb: look for at least 1,100 lumens
    Replacing a 100W bulb: look for at least 1,600 lumens

    After lumens, the next concept you’ll want to be sure to understand is color temperature.
    Generally speaking, incandescents sit at the bottom of the scale with their yellow light, while CFLs and LEDs have long been thought to tend toward the high, bluish end of the spectrum.

    Unless you live in a disco, you probably want the colors in your home to look somewhat traditional. This is where the color rendering index, or CRI, comes in.
    Manufacturers aren’t required to list the bulb’s CRI number on the packaging
    the CRI is highly imperfect and not always useful
    CRI scores are really only helpful if you’re talking about bulbs that sit in the middle of the color temperature spectrum.
    In general, anything over 80 is probably decent enough for your home
    And if you’re buying bulbs on the high (blue) or low (yellow) end of the spectrum, take any and all CRI claims with a grain of salt.

  10. Dolly Yang says:

    Dear Manager,

    How is the business going? This is dolly from GuangTuoDa lighting.

    We would like suggest you to try our 5W 7w gu10 dimmable led spotlights as a new product.

    Here is the specifications:
    2.Watts:5W 7W
    3.Input Voltage:100V-130V/220V-240VAC/12V
    4.Rendering Index:WW>80 WW>90
    5.Beam Angle:15/25/38/60
    6.Light Source:SMD2835 led
    8.Housing Color:White/black/Silver
    9. Material: Aluminum+PMMA
    11.Dimension:50*54mm(GU10) 50*48.5mm(MR16)
    12.Certificates: CE ROHS TUV GS ERP ETL

    As a 7 years experience factory.we do exported large quantity of led lamps. I would like to underline again that GuangTuoDa lighting is not only a led bulb manufacturer, but also a led driver manufacturer.Here is our websites which sell drivers http://gtdlighting123.1688.com.

    For our dimmable lamps, it dimming smoothly and it compatible with a variety of triac dimmers. such as Lutron, leviton,Miko,Mikro,kopp,GIRA,BUSCH,Schneider,MK and other dimmers.It works well both for Leading edge and trailing edge dimmers.

    OEM is available! Single box packaging,six pack packaging,ten pack packaging and blister packaging is available!

    Shall we check the samples now?

    Dolly Yang
    GuangTuoDa Lighting CO.,LTD
    M:+86 13528844813
    W: http://www.gtdlights.com
    Skype: gtdlights02
    Address: 3rd Floor,Building G, Wanda Industrial Park,Zhoushi Road,Shiyan Town,Bao’an District, Shenzhen City,518108, China

    • Tomi Engdahl says:

      If you want to drop few free samples to me for testing, I can test them and write my comments on them to the ePanorama.net blog.
      If interested reply to this or e-mail I sent.

  11. Tomi Engdahl says:

    Honey, I retrofitted the car’s interior lights with LEDs

    A dead battery in my SO’s car got me thinking about ways to reduce the chance of that happening again – to either of us. Why not replace the interior car lights with LED versions?

    Sure enough, hitting the Web revealed gazillions of choices. Car interiors commonly use wedge-base bulbs, and festoon bulbs, the name given to cylindrical lamps with a contact cap at each end. Who knew?

    Being a cheapskate, even the reasonable prices I was seeing were more than I wanted to spend. After all, how many times have we all ended up with junk when trying a relatively new product category? Sometimes paying more results in better product, but often not.

    So, this seemed like a good time to see what China Inc. had for sale. I was not disappointed!

    My car has 5W festoon lamps in the front doors, two 8W reading (map) lights, and an 8W dome light. The cargo dome light is a 13W wedge-base. That’s what the car manual says.

    No surprise: the 3-LED lamps are more sensitive to the bus voltage. The shocker is claimed vs. actual power.

    FYI, the 1-LED lamps were about $1.25 each; the 3-LED lamps, about $2.

    Obviously, a 1-LED lamp incurs a ridiculous waste of power with a 12V-15V automotive supply. Even so, it’ll likely use less power than the incandescent it replaces, assuming a directional beam is okay. Still, 3-LED parts seem preferable.

  12. Tomi Engdahl says:

    LED light to produce the entire light spectrum

    American Silicon Valley headquartered LED Engin has introduced led component, which was the first in the world to produce seven different colors. It can be implemented in the entire color spectrum repetitive stage light applications.

    LZ7 circuit 7 is independently controllable LEDs 7 x 7 millimeters platform. Chassis development has been a core material and design of thermal management.

    Source: http://etn.fi/index.php?option=com_content&view=article&id=4201:ledivalo-tuottaa-koko-valospektrin&catid=13&Itemid=101

    LuxiGen™ Multi-Color Emitter Series
    LZ7 Flat Lens Emitter
    RGBW-PC Amber-Cyan-Violet

    7-color surface mount ceramic LED package with integrated flat glass lens
    Red, Green, Blue, Cool White, PC Amber, Cyan and Violet enables richer and wider color combination for more sophisticated color mixing
    Compact 3.8mm Light Emitting Surface (LES) and low profile package maximize coupling efficiency into secondary optics
    20W max power dissipation in a small 7.0mm x 7.0mm emitter footprint

  13. Tomi Engdahl says:

    What you don’t know about LED light intensity curves for grow light apps

    The light intensity curves for LEDs, regardless of whether they are collimated with a lens or reflectors, follow a bell shaped curve (often referred to as a “Lambertian“ curve). The 50% intensity point for an LED with no optic (bare LED) is virtually always at approximately 120 degrees (60 degrees in each direction).

    The 50% point (known as the “beam angle” or “viewing angle”) is a lesser number of degrees depending on the collimating specification used. The beam angle is the total angle in both plus and minus directions.

    What is not commonly known by those not experienced in the physics of LED light emission and optics is that the Lambertian LED light intensity curves can be very misleading in terms of how much light is actually arriving at the receiving end.

  14. Tomi Engdahl says:

    LEDs in stores could leave a bad taste in your mouth

    According to recent research, narrow-spectrum 405-nm visible-light from an LED source can provide decontamination in several applications. Exposure to blue-light wavelengths inactivates some bacteria, but according to a study at Cornell University, LED source exposure for as short a time as a few hours, degrades the perceived quality of milk.

    What this means is that, potentially, all of those money-saving lights installed in stores and in display cases may be creating havoc with milk. Researchers at Cornell’s Department of Food Science discovered that when consumers tasted two-week old milk not exposed to LED light and then fresh milk exposed to light for only four hours—the older milk tasted better. One could wonder what other dairy and non-dairy products are similarly affected.

    What happens in the milk is that riboflavin and other photosensitive components are activated by light energy. They release electrons that degrade proteins and oxidize fats.

    So, what’s going on? The LEDs produce wavelengths that are quite different from fluorescent bulbs used in display cases, and emit 460 nanometers in the blue spectrum, creating a broader emission peak than fluorescents. The peak is close to the narrow band where riboflavin absorbs light, which could be selectively destroying the nutrients and damaging the quality of the milk.

    This is not the first time that milk taste and integrity was questioned. Promolux, for example, is combating the same problem. They describe the challenge as, “When milk is exposed to sunlight or to the fluorescent lighting commonly found in refrigerated dairy display cases, the light initiates two chemical reactions which result in off-flavors and the loss of nutrients.

  15. Tomi Engdahl says:

    Nano-structured InGaN LED Yields White Light

    The holy grail of LED lighting, achieving white light in the most efficient and cost-effective way is a hot topic, both among established manufacturers and in academia.

    Traditional approaches include color down-conversions, combining high energy LEDs emitting in the blue or near ultra-violet band with a mix of phosphors that re-emit at different wavelengths. Generally, this approach emulates an incomplete white light spectrum at a lesser quantum efficiency than the original emitter (the LED covered in phosphor). The phosphors’ limited lifetime compared to that of the actual LED illuminating them can also negatively impact the overall longevity of the white light.

    Other solutions combine multiple LED dies emitting at different peak wavelengths, but here again, white is a short-lived illusion, missing out on the natural continuum of true white light.

    A team of researchers from the University of Hong Kong is confident broadband white light could be obtained from monolithic LED dies. In their recently published ACS Photonics paper “Monolithic Broadband InGaN Light-Emitting Diode”, the researchers disclose promising results using high indium content InGaN-GaN quantum well structures grown on a sapphire substrate.

  16. Led Light Supply says:

    I have found that your blog deeply tells characteristics of Led Bulbs like Lumen Value, Color Temperature, color rendering, Beam Shape . Which is very useful when your thinking of buying a good new Led Bulbs.

  17. Jonathan Marshall says:

    We have attempted to source the best equivalent 50W equivalent LED bulbs. The video on the web link shows one of the few side by side comparisons between a 50W halogen and 4W led. http://www.leds4less.co.uk/50w-gu10-halogen-equivalent-led-smd-bulbs–series-ii-161-p.asp

    Since the video technology has improved to achieve even more aesthetically pleasing products http://www.leds4less.co.uk/gu10-led-bulb–classic-glow–50w-halogen-equivalent–integral-554-p.asp that when fitted look almost identical to traditional halogen spotlights.

  18. Tomi Engdahl says:

    LED light mimics incandescent lamp

    Sharp has introduced a series ofLED components, which can be used to mimic the behavior of light bulbs familiar light dimming. The new Zenigata series Dimming the LEDs change color temperature as well as the old incandescent lamps.

    Sharp LEDs do not need any special electronics. Dimming successful standards for adjusting the amplitude of the drivers.

    Source: http://etn.fi/index.php?option=com_content&view=article&id=5431:ledivalo-matkii-hehkupamppua&catid=13&Itemid=101

    Sharp’s popular Natural Toning ZENIGATA LEDs set the tone once again

    Sharp Devices Europe (SDE) has launched the second generation of its Natural Toning ZENIGATA COB LEDs, which warm as they are dimmed. The new models offer an expanded CCT range and enhanced energy efficiency.

    Available in the popular Mini ZENIGATA footprint, Natural Toning technology automatically tunes the colour temperature from 3000K down to as low as 1900K as the LED is dimmed. This mimics the behaviour of conventional incandescent sources, which is desirable for instance in hospitality and retail applications. Natural Toning ZENIGATA COBs require no special control electronics; a standard amplitude-dimming driver is all that’s required, making them easy to integrate and simple to operate.

  19. Tomi Engdahl says:

    Deadly LED lamps from China on ebay.

    Just a couple of the wide range of LED lamps openly sold on ebay that have deliberately exposed solder connections directly referenced to the mains supply. Both lamps in this video have the potential to cause a serious electric shock.

  20. Tomi Engdahl says:

    Designing Circuit Protection for Indoor LED Light Bulbs

    Since the earliest versions of indoor LED light bulbs were developed, their designers have faced a variety of technical challenges. These include AC-to-DC power conversion, thermal design/heat-sinking, physical space constraints imposed by the current light bulb sizes, electrical transients — all in addition to the basic challenge of driving the LEDs that produce the light. One of the most significant of these challenges is providing protection from transients for both the LEDs and all the active and passive components upstream from them in the circuit. These transients are typically the result of lightning-induced surges on the AC input. These threats mean that LED bulbs require both over-current and over-voltage protection.

    The growing demand for added functionality and higher light output has added to the number of components that must be placed on the LED board. The higher light output creates a demand for larger heat sinks to dissipate the heat produced by higher power LEDs. Because LED bulbs are intended to be form factor-compatible with current incandescent and CFL bulbs (such as the popular A19 bulbs typically used in household lamps), they include an AC/DC power supply circuit so they can operate from standard bulb sockets (Figure 1). Anything directly connected to an AC power source can be damaged by short circuit and overload conditions caused by component and/or circuit failures inside the bulb. In addition, lightning surges or load switching transients (originating outside the bulb) can create voltage spikes or ring waves that can stress and ultimately damage components inside the bulb.

    The AC input circuit AC fuse is the primary over-current protection device for the bulb. When properly selected for all of the required design parameters, this fuse will adequately protect all downstream components from Electrical Overstress (EOS) damage from induced transients and short circuit/overload conditions by safely disconnecting all circuitry from the AC line input.

  21. Tomi Engdahl says:

    More Than Efficient Lighting: An Effective LED Driver Using an 8-Bit MCU
    An 8-bit microcontroller can create an effective LED driver and add advanced features that make the lighting solution even more attractive.

    In today’s energy-conscious environment, LEDs are often favored over conventional light sources. This is because of their inherent low power and long life. In addition to this, since LEDs are solid-state lighting (SSL), they can be dimmed, allowing the user to create fantastic lighting effects while reducing the overall power consumption.

    Obtaining these benefits from LEDs requires an effective LED driver. The LED driver’s effectiveness is linked to its ability to provide an efficient energy source, to ensure LED’s optimal performance and to maintain the long life of LEDs, even both as the driver keeps the LED output intensity constant and while changing intensity. Also, an LED driver that is intelligent and has advanced capability can make lighting solutions even more attractive.

    Although an effective LED driver can offer many advantages, there are also challenges in its implementation. This article will show how an 8-bit microcontroller (MCU) can be used to alleviate design challenges and create high-performance LED driving solutions with capabilities beyond that of traditional solutions.

  22. Tomi Engdahl says:

    SSL Annex publishes performance recommendations for LED-based lighting applications

    Seven IEA 4E SSL Annex documents cover performance guidelines in distinct applications ranging from omnidirectional A-lamps to street lights with the hope of harmonizing global markets.

    The IEA (International Energy Agency) 4E SSL Annex has issued seven new documents establishing performance guidelines for LED-based solid-state lighting (SSL) products in specific applications. The agency that has backing from major countries around the globe hopes to harmonize performance requirements across regions, although for now market-transformation or regulatory programs within countries will not be compelled to acknowledge the recommended guidelines. Still, the new SSL performance documents covering areas from omnidirectional A-lamps to street lights represent the thinking of some of the top experts in the LED lighting sector.

    The SSL Annex will focus on performance tiers with varying requirements that range from baseline SSL products that can save energy and perform functionally in the intended application to premium tier performance that maximizes energy savings and light quality.

    “The performance tiers are one important activity that we carry out in the IEA 4E SSL Annex,” said Peter Bennich, chairman of the SSL Annex government management committee. “In the Annex, we focus on issues and topics that regularly are of concern for governments, and provide data and guidance to help policy makers make informed choices.”

    The newly-published guidelines focus on non-directional lamps, directional lamps, downlight luminaires, linear LED lamps meant to replace fluorescent tubes, outdoor lighting including street lighting, high/low-bay LED luminaires, and planar luminaires. You can peruse the performance guidelines for each application on the SSL Annex website.

    Tier 1 products would only need to meet efficacy of 65 lm/W while Tier 3 products would be held to a much higher performance milestone at 125 lm/W.

    The SSL Annex said the Tier 3 requirements are meant to be used by higher-end market transformation programs such as Energy Star in the US. The lower tier programs might be used by governments in less-developed countries where affordable lamps, and indeed basic electric lighting, are vital to economic development.

    Product Performance
    The IEA 4E SSL Annex is active in two main important areas that relate to product performance.

  23. Jeff` says:

    You should always have your most recent content at the top of your page, not at the bottom. You should reverse the chronology of your comments. Helpful information. Thanks.

  24. Tomi Engdahl says:

    How to Replace / Convert a Halogen Floodlight with an LED Chip

  25. Tomi Engdahl says:

    Mains Voltage LED (and how NOT to handle mains voltage!)

    Testing a mains voltage LED from China. This one is rated 220V and 20W. It really can be connected directly to AC mains with no LED driver. 30W and 50W versions are also available. In the listings it’s called “smart IC” or “integrated driver” or “driverless” COB LED.

  26. Tomi Engdahl says:

    Halogen Downlight Lamps – Dichroic vs Aluminium Reflectors

    MR16 halogen lamps with two types of reflectors – dichroic and aluminium. With a dichroic reflector, most of the heat is emitted from the back of the lamp. These should NOT be used in downlight fittings, as they will cause overheating. Dichroic lamps are designed for use in display lighting, where the lamp is in an open fixture so that the heat can be dissipated, and the beam of light does not heat up the object it is illuminating. For use in downlights and other room lighting applications, aluminium reflectors should be used, so that most of the heat is emitted from the front. This will avoid the fitting overheating, which will cause damage and possibly a fire. Plenty of retailers and websites describe these lamps incorrectly, so it is best to check the lamp itself using the simple method shown in the video.

  27. Tomi Engdahl says:

    Downlights, Fire Rating, Fire Hoods & Loft Covers

    Downlights or recessed lights are available as fire rated or not, separate fire hoods can be obtained, and covers to provide suitable space over lights so that insulation can be installed above them.


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