Мощность светодиодных лампочек: перевод мощности обычной лампы в светодиодную

Таблица сравнения светодиодных ламп и ламп накаливания: различия, плюсы и минусы

Лампы накаливания долгий промежуток времени использовались для освещения. Но сейчас на рынке распространена продажа светодиодных ламп. Чтобы определиться, какой источник света лучше, надо провести сравнительный анализ конструкций, принципа работы, мощностей.

Различия в конструкции и принципе работы

Чтобы провести сравнение ламп накаливания и светодиодных, надо рассмотреть конструкцию и принцип работы каждого источника.

Первым рассматривается вольфрамовая лампочка накаливания.

Устроена она следующим образом:

• Цоколь. Нужен для вкручивания лампочки в патрон. Обычно изготавливается из алюминия.
• Колба. Материал изготовления – стекло. Защищает вольфрамовую нить от воздействия внешней среды. Внутри создается вакуум или заполняется инертным газом. Газ не дает металлическим элементам окисляться.
• Электроды, крючки для их удерживания. Данные элементы удерживают нить накаливания.
• Нить накаливания. Изготавливается из вольфрама, служит для излучения света.
• Штенгель. В нем закреплены электроды с крючками. Сам он находится в нижней части колбы.
• Изолирующий материал, контактная поверхность.

Принцип работы заключается в проведении тока через источник и разогрев вольфрамовой нити до высоких температур. В результате чего она начинает излучать свет. Нить прогревается до 3000 градусов, при этом не расплавляется.

Внешне диодная лампочка напоминает предыдущую конструкцию. Она также содержит цоколь с резьбой таких же размеров (маркировка тоже одинаковая), поэтому переделывать оборудование или светильники под низ не надо. Но отличие в более усложненной внутренней конструкции:

• Контактный цоколь.
• Корпус.
• Плата питания и управления. Нужна, чтобы не допустить перегорание светильников. Они снижают напряжение, выравнивают ток.
• Плата со светодиодами.
• Балластный трансформатор.
• Прозрачный колпак.

Световой поток образуется при соприкосновении двух веществ из разных материалов, через которые был пропущен ток. Главным условием является то, что один из материалов заряжен отрицательными электронами, другой – положительными ионами.

Сравнение основных параметров

Чтобы определиться с основными параметрами, надо провести анализ технических характеристик. Первоначально рассматривается вольфрамовый ресурс:

• Требуемое напряжение от источника 220–240В.
• Мощность в пределах 15–200 ватт.
• Температура прогревания накала 2700–3200К.

Чем больше показатель цветовой температуры, тем короче срок службы.

• Тон светового потока тепло желтый.
• Срок службы до 1000 часов.
• Рассеиватель света открытый, поэтому угол рассеивания на 360 градусов.

Светодиодная конструкция имеет такие же параметры, то другие показатели:

• Требуемое напряжение от источника 12 или 220В.
• Мощность в пределах 60 ватт.
• Цветовая температура 2700–6000 К.
• Тон светового потока теплый, холодный, нейтральный.
• Срок службы 30000–100000 часов.
• Угол рассеивания на 120–360 градусов. Зависит от конструкции лампы.

Сравнивая описанные характеристики заметно, что вольфрамовый проводник уступает по многим параметрам светодиодному источнику.

Таблица соответствия мощности

В быту используются вольфрамовые с мощностью 40–100 ватт. Для анализа проводится соответствие данным показателям данных светодиодных ламп. Результаты занесены в таблицу светодиодных и ламп накаливания:

Мощность лампы накаливания, ватт	Мощность светодиодной, ватт	Средний световой поток, лм
40	5	400
60	7	560
75	11	880
100	13	1040
150	20	1600
200	30	2550
300	40	3450
500	60	5200

Результаты показывают, что заявленным данным ламп накаливания соответствуют данные светодиодного источника в 8 раз меньше. Преимуществом обладают СЛ, так как потребляемая мощность меньше, а срок службы больше.

Обзор плюсов и минусов

В соотношении светодиодных ламп и ламп накаливания, светодиодные лампочки очень экономичны и с длительным сроком эксплуатации.

Учитывая сроки службы, проводится анализ, что за период эксплуатации одной светодиодной лампочки потребуется 50 ламп накаливания (расчеты по среднему значению).

Но диодные конструкции тоже имеют свои отрицательные стороны: высокая цена, но быстрая окупаемость.

Диодный вариант освещения имеет более широкий ряд цветового освещения, в то время как ЛН всего один.

Диодный прибор не требует обслуживания, но к концу срока службы возможно снижение эффективности, что вызвано мутнением кристалла.

Вольфрамовый источник сильно нагреваются в процессе работы, на это уходит половина затраченной энергии, что приводит к низкому коэффициенту полезного действия. КПД диодных источников гораздо выше, так как нагрев у них минимальный.

Освещение используется в темное время. Глаза человека к этому времени устают и требуют спокойного на них воздействия. Поэтому освещение должно быть теплым. Этот пункт полностью выполняет ЛН, так как СЛ в основном излучает белые оттенки, причем в световом потоке наблюдается присутствие синего оттенка, который негативно влияет на зрение (особенно детское). Такого плана освещение лучше применять в офисах, производствах.

Среди СЛ встречаются подделки, характеризующиеся плохим качеством сборки. Также они негативно влияют на зрение мерцанием.

Перед покупкой надо убедиться, что пульсация светового потока не превышает 5 процентов.

Рекомендуем посмотреть видео:

В заключение

Все технические характеристики указывают на преобладание преимуществами светодиодными лампами. Но выбор остается за потребителем, потому что не у всех есть возможность сразу оплатить диодный источник.

Полезная информация? Оставьте комментарий, поделитесь статьей в соцсетях.

90000 Basics of High Power LED Lighting 90001 90002 LEDs are appropriate for many lighting applications, they are designed to produce a lot of light from a small form factor while maintaining fantastic efficiency. Here at LEDSupply there are a variety of LEDs for all kinds of different lighting applications, the trick is knowing how to use them. LED technology is a tad different than other lighting that most people are familiar with. This post is here to explain everything you need to know about LED lighting: how to power LEDs safely so you get the most light and the longest lifetime possible.90003 90004 What Exactly is an LED? 90005 90002 An LED is a type of diode that turns electrical energy into light. For those that do not know, a diode is an electrical component that only works in one direction. Basically an LED is an electrical component that emits light when electricity flows through in one direction, from the Anode (positive side) to the Cathode (negative side). 90007 LED is an acronym standing for ‘90008 L 90009 ight 90008 E 90009 mitting 90008 D 90009 iode’. Basically, LEDs are like tiny light bulbs, they just require a lot less power to light up and are much more efficient in producing high light outputs.90003 90004 LED Types 90005 90002 In general terms, we carry two different types of LEDs: 90003 90002 5mm Through-Hole & Surface Mount. 90003 90021 90022 5mm LEDs 90023 90024 90002 90026 5mm LEDs are diodes inside a 5mm diameter lens with two thin metal legs on the bottom. They are used in applications where a lower amount of light is required. 5mm LEDs also run at much lower drive currents, maxing out at around 30mA, whereas Surface Mount LEDs require a minimum of 350mA. All our 5mm LEDs are from top manufacturers and are available in a variety of colors, intensities and illumination patterns.Through-hole LEDs are great for small flashlight applications, signage and anything where you are using a breadboard as they can be used easily with their leads. Check out our guide to setting up 5mm LEDs for more info on these tiny light sources. 90003 90021 90022 Surface Mount LEDs (SMD) 90023 90024 90032 90002 Figure 1 — Bare Emitter 90003 90002 Surface Mount LEDs are diode (s) that can be placed on a substrate (circuit board) with a silicon dome over the diode to protect it (see Fig.1). We carry high-power Surface Mount LEDs from industry leaders Cree and Luxeon. Both are excellent in our opinion, that is why we carry them after all. Some prefer one over the other but that comes with experience and knowing what to look for. Cree tends to have higher listed Lumen outputs and are a market leader in the High-Power LED sector. Luxeon, on the other hand, has excellent colors and thermal control. 90003 90002 High Power LEDs come as bare emitters (as seen in Fig. 1) or mounted to a Metal Core Printed Circuit Board (MCPCB).The boards are insulated and contain conductive tracks for easy circuit connections. Our 20mm 1-Up and 3-Up star board designs are the best sellers. We also offer QuadPod’s which can hold 4 high power LEDs on a board slightly larger than the 20mm stars (see Fig. 2). All our high power LED options can be built on a linear design as well. The LuxStrip can house 6 LEDs per foot and are easily connected up to 10 feet long. 90003 90039 90002 Figure 2 — MCPCB Options 90003 90004 Polarity Matters: Wiring LEDs 90005 90002 Electronic polarity indicates whether a circuit is symmetric or not.LEDs are diodes, therefore only allowing current to flow in one direction. When there is no current flow, there will be no light. Thankfully this means that if we wire an LED in backwards, it will not burn the whole system up, it just will not come on. 90003 90002 The positive side of the LED is the Anode and the negative side is the Cathode. Current flows from the anode to the cathode and never in the other direction, so it is important to know how to tell the anode and cathode apart. For surface mount LEDs this is easy as the connections are labeled, but for 5mm LEDs ook for the longer lead which is the anode (positive), take a look at Figure 3 below.90003 90048 90002 Figure 3 — Finding the anode and cathode of an LED 90003 90004 Color Options 90005 90002 One of the great things about LEDs is the different options and kinds of light you can get from them. 90003 90021 90022 White LEDs 90023 90024 90002 Correlated Color Temperature (CCT) is the process of creating different white light at different temperatures. Color temperature is specified in degrees Kelvin (K), which is a temperature scale in which zero occurs at absolute zero and each degree equals one Kelvin.The lower temperatures from 3,000K to 4,500K tend to be a warmer to neutral white. The higher temps 5,000K + are the cool whites, also known as ‘daylight white’. 90003 90021 90022 Color LEDs 90023 90024 90002 For colors, what really matter is the wavelength in nanometers (nm). For certain applications colors are needed for the visual effect, but sometimes certain wavelengths are needed for applications like curing, growing, reef tank lighting, and much more. See Fig. 4 for an idea of ​​what wavelengths and temperatures produce certain colors.90003 90067 90002 Figure 4 — LED colors and color temperature 90003 90002 We try to carry similar color temperatures and wavelengths for each brand and type of LED. You can always find the color or wavelength of our LEDs on the sub-section of the product page and can even search by color from our LEDs dropdown menu on the homepage. In white, we carry 3000K, 4000K, 5000K and 6500K. As far as colors go, we carry from 400-660nm. 90003 90004 LED Brightness 90005 90002 LEDs are not only known for the colors, they are also a lot brighter than other light sources.Sometimes it is hard to tell how bright an LED will be because it is measured in Lumens. A Lumen is a scientific unit measuring luminous flux or the total amount of visible light from a source. Note that 5mm LEDs are usually listed in millicandelas (mcd). For 5mm LEDs, their viewing angle also affects the light output they give off, for more on that see here. 90003 90021 90022 Why drive current matters … 90023 90024 90002 The amount of light (Lumens) an LED emits depends on how much current is supplied.Current is measured in milliamps (mA) or amps (A). High-power LEDs can take currents from 350mA to 3000mA. LEDs vary on their current ratings so be sure to keep track of this when picking an LED and driver. 90003 90021 90022 Determining the Brightness 90023 90024 90002 Now comes the tricky part, selecting the LED and driver combination that will output the light needed. We have done a lot of the ground work here, in a post measuring the brightness of each high power LED at different drive currents.Take note that these are measures for 1-Up stars so if you want more light the 3-Up LEDs are a good option as they are triple the light within the same footprint. 90003 90002 The above resource can always be used for determining the light output from an LED, but finding it manually is not very hard. 90003 90002 To do so, information is needed from the data sheet of the LED. On all of our LED pages we link to the manufacturers data sheet at the bottom of the page. 90003 90092 Example: Finding brightness of Cree XP-L at 2100mA 90093 90002 In this example we are using the Cree XP-L.First find the Flux Characteristics table (figure 5). We will touch on binning later which is labeled in the ‘Group’ column, but let us assume we are going to use a cool white XP-L from the highest bin (v5). The highlighted number is the typical flux @ 1050mA which is the current the XP-L is measured at. To the right of that are the typical Lumen numbers for 1500, 2000, and 3000mA drive currents. 90003 90096 90002 Figure 5 — LED Luminous Flux Chart 90003 90002 For the sake of this example, say we want to run this LED with a 2100mA BuckBlock LED 90100 driver and we need to find what the light output would be like.When driving an in-between drive current that is not listed, find the relative flux vs. current graph on the data sheet that looks like the graph to the right. 90003 90002 The arrow is the tested (base) output (at 100% relative flux). Following the curve to 2100mA (?) We see that this is a 75% increase in light. Taking the 460 lumens from above and multiplying it by 1.75 we can see that the cool white XP-L running at 2100mA gives off about 805 Lumens. 90003 90002 It may be hard to find the LED and Lumen output needed when switching to LEDs.This is due to the fact that light was always measured by the wattage of a bulb. LEDs have much better efficacy which makes it nearly impossible to measure in this way anymore as a 50 Watt LED will be significantly brighter than a 50 Watt Incandescent. In Figure 7 we show different incandescent bulbs and how many Lumens they give output. This helps give a better idea of ​​the light to expect from an LED and if it will be as much as the old lighting. 90003 90106 90002 Figure 6 — Incandescent Wattage to Lumens 90003 90004 Viewing Angle and Optics 90005 90002 Our 5mm LEDs have listed viewing angles for each so just search for one that will work for you.As far as our surface mount LEDs go, most of them give off a very wide angle at 125 degrees! Luckily, the LED star boards are compatible and easy to use with LED optics. These secondary optics are used to focus the light, they can reflect the light from an LED into spot, medium spot, wide spot, or elliptical and oval patterns. 90003 90002 As seen in Figure 8, 1-Up optics are cone shaped and require an optic holder. In the case of our LED boards, optic holders have four legs that sit down into the grooves of the star.Triple LED stars are also compatible with Carclo optics, built with three holes in the board for the legs of the optic to fit in. 90003 90115 90002 Figure 7 — LED optics and holders 90003 90004 How to Power LEDs 90005 90002 LEDs are known for having the best efficacy out of all other light sources. Efficacy is the measure of how well a light source produces visible light, also described as Lumens per Watt. In other words, how much light are we getting for our watt of power. To find this, first find out the wattage of the LED in use.In order to find watts you need to multiply Forward Voltage (the voltage at which current starts to flow in the normal conducting direction) by drive current in Amps (note that it NEEDS to be in amps … not milliamps). Let’s take a look at the Cree XP-L 1-up LED as an example. 90003 90122 90002 Figure 8 — Forward Voltage of an LED 90003 90002 Say we are running this Cree XP-L at 2000mA. From Figure 8 you can see that at this drive current the forward voltage is 3.15. So to find watts we multiply 3.15 (forward voltage) by 2 A (2000mA = 2 Amps) which comes out to be 6.3 Watts. 90003 90002 So now to find Efficacy, we just need to divide 742 Lumens (the tested amount of Lumens for this LED at 2000mA) by 6.3 Watts. So the Efficacy (Lumens / watt) of this Cree XP-L is 117.8. This is great efficacy but also note Cree boasts that the XLamp XP-L LED has breakthrough efficacy of 200 lumens / watt running at 350mA. It is good to know that the efficacy goes down as you run more current to the LED as this increases heat which does make the LED a bit less efficient.Sometimes you will need to accept this if you need the LED to be very bright, but if you are wanting to get the best efficacy then you should run LEDs at a lower current. This is all helpful in determining how much power your applications will need as well as figuring out energy savings down the road. 90003 90021 A little bit more on LED drivers 90024 90002 This means that you need to find an LED driver that has the capability of driving LEDs at the current you need in order to get the amount of Lumens you’d like.An LED Driver is an electrical device that regulates the power to an LED or string (s) of LEDs. The driver responds to the changing needs of the LED by supplying a constant amount of power to the LED as its electrical properties change with the temperature. A good analogy in understanding this is that of a car on cruise control. As the car (LED) goes through hills and valleys (temperature changes), the cruise control (driver) makes sure it stays at a steady speed (light), regulating the gas (power) needed in doing so.The driver is so important because LEDs require very specific electrical power in order to operate properly. If the voltage supplied to the LED is lower than required, very little current runs through the junction, resulting in low light and poor performance. On the other hand, if the voltage is too great, too much current flows to the LED and it can overheat and be severely damaged or fail completely (thermal runaway). Always make sure you check the LEDs datasheet so you know what current is recommended to avoid these issues.90003 90004 How much voltage do I need to light up an LED? 90005 90002 This is a common question asked and is actually pretty easy to figure out. All you need to know is your LED (s) forward voltage. If you have multiple LEDs in series than you need to take into account all the forward voltages combined, if you have a parallel circuit than you only need to take into account the forward voltage of how many LEDs you have per string. For more on wiring setups see here. It is a good idea to keep at least a 2 volt overhead as some drivers (like the LuxDrive drivers) require this for the driver to work properly.So if your total forward voltage for a series circuit is 9.55, you should be safe with a 12V supply. For off line drivers (AC input) just know the output voltage they are rated at and make sure you are covered, so a AC input driver with an output range of 3-12VDC would work for this application as well. 90003 90004 Heat Control 90005 90002 Finding wattage of your sytsem also helps you know more about the heat control you will need. Since these LEDs are high-power, they do create heat which can be very bad as you can learn here.Too much heat will make the LEDs produce less light as well as cut down on the lifetime. We always recommend using a heatsink and like to say to use about 3 square inches for every watt of LEDs. For larger wattages I would recommend looking for a heatsink that is recommended for the amount of watts you are running. 90003 90004 LED Binning & Quality 90005 90002 With the LED industry growing at a pretty rapid pace right now, it is important to understand the difference in LEDs out there. This is a common question as LEDs can range from very cheap to very expensive.I’d be careful in buying cheap LEDs as you always get what you pay for, yes the LEDs might work great at first but they usually tend not to last as long or will burn out fast because of poor testing. 90003 90002 All the LEDs carried here at LEDSupply are carefully selected. We only stock the best brands and color temperatures. Our vast experience in the industry has helped us learn the importance of quality manufacturing and binning of LEDs as well. In the manufacturing of LEDs, there is a variation of performance around average values ​​in the technical data sheets.For this reason manufacturers bin the LEDs for luminous flux, color and forward voltage. We select the bins with the highest luminous flux (visible light) and lowest forward voltage, as this makes sure we have the LEDs with the best efficacy. A large amount of LED products are cheaply made and not documented correctly, which leads to many failed projects and then makes people think LEDs actually do not last as long as they are said to. With our experience and buying power, we are able to offer the best products at reasonable prices.90003 90002 This should give you a good start to understanding LEDs and what to look for, but if you have more questions or would like more info on a certain product and whether it would work for you, we are here to help. Just email us at [email protected] or call us at (802) 728-6031 to chat with our very knowledgeable Tech Support Team. 90003 .90000 What’s inside and LED bulb 90001 90002 by 90003 LELAND TESCHLER, Executive Editor 90004 90005 90002 Surprise: A look inside five LED bulbs designed to replace 60-W incandescents reveals design regimes ranging from dead simple to startlingly sophisticated. 90005 90002 The average consumer might think that when it comes to light bulbs, one is about the same as another. This view might have been accurate back when every light socket contained an incandescent lamp. It is certainly not true for the LED bulbs designed as incandescent replacements.90005 90002 We came to this conclusion after tearing down five LED bulbs marketed as equivalents for 60-W incandescent bulbs. The five bulbs we chose all got high marks from Consumer Reports Magazine. But that’s where the commonality stopped. When we got inside, we found vastly different approaches in construction techniques, thermal management and electronics design. 90005 90002 We start with a bulb called the E27 A19 LED from Home EVER Inc. in Las Vegas. The mechanics of the bulb and its electronics are dead simple.The two-sided circuit board seems to have been reflow soldered. Two wires connect the board to a metal plate holding 30 LEDs. Two more wires go to the light socket conductors. All four of these wires look as though they were hand-soldered. 90005 90014 90002 The plastic enclosure for the Home EVER ac / dc converter slid out of the heat sink bottom. The converter board (right) sits in the plastic enclosure. 90005 90002 The bulb is built around a 2-in.-high heat sink that weighs 2 oz and looks to be a metal casting.The base of the lamp contains a plastic housing that holds the ac / dc converter. The electrical connections to the lamp socket are at one end of the housing. The other end attaches to the heat sink with two small screws. 90005 90019 90002 The Home EVER bulb’s heat sink and plastic base holding the ac / dc converter with the metal screw threads removed. > Here, the base foot connection is still wired to the converter. 90005 90002 Additional attachments to the heat sink are a frosted polycarbonate bulb that encloses the LEDs and a 2-in.-diameter metal plate containing the LEDs. The plastic bulb apparently snap-fits into the heat sink while the LED plate attaches with three screws. There’s a couple spots of compound for thermal conduction applied between the LED plate and the heat sink. 90005 90002 The ac / dc converter design is straightforward. The only non-SMD components are two big capacitors, a surge resistor on the input and a transformer. Connections from the board to the screw-base and to the LED board are through discrete wires, but the connection to the bulb foot contact was done by machine.The electrical connection to the metal screw threads, though, is simply a length of bare wire squeezed between the plastic housing and the inside surface of the screw threads. 90005 90002 The electronics on the ac / dc converter are bare bones. The diode bridge on the input is four discrete diodes. There is a single IC on the board. It is a buck topology supply designed to provide a constant current and is made by Bright Power Semiconductor (BPS) in China. The chip, dubbed BP2812, incorporates a 600-V MOSFET.The spec sheet lists the chip operating current at 200 μA. 90005 90028 90002 A view of the Home EVER PCB reveals the four diodes making up the rectifying bridge and the BP2812 chip (bottom). The other side of the board (top) holds the energy handling components and the fusistor on the input. 90005 90002 The «typical application circuit» listed on the BP2812 spec sheet comes extremely close to the actual circuit we found on the LED’s circuit board. Seven resistors go into simple networks that handle the Vcc voltage, sensing the buck inductor’s peak current, and regulating the input voltage to the IC.Five capacitors handle chores of ac line filtering, an ac by-pass for the Vcc pin and line-sense pins, and the buck topology. An in-line fuse cuts the power to the whole circuit in the event of too-high current draw. 90005 90002 Judging by graphics on the BPS web site, it looks as though BPS may have assembled the board itself. There are images there of example boards for a few other LED applications that look remarkably similar to this one. 90005 90035 90002 The chip powering the Home EVER LED bulb is basically a constant current source powering an onboard MOSFET.The reference circuit from chip-maker Bright Power Semiconductor is close to what we found on the PCB. 90005 90002 It should be noted that the effect of temperature on LED operation does not seem to be factored into the ac / dc converter. LEDs put out less light as their temperature rises. That’s generally not a problem for small temperature changes. The eye’s sensitivity to light is logarithmic, and the eye is not particularly sensitive to small changes in luminosity. It’s not unusual to see a 10% drop in LED lumen output as junction temperature rises from room temperature to 150 ° C.90005 90002 But LED current can also be reduced at higher temperatures as a way of lessening the need for heat sinking. That said, there is no temperature sensing that we could see in the Home EVER bulb’s ac / dc converter. And there is no circuitry for dimming. 90005 90002 But all in all, the LED bulb probably works well in uses that do not need a dimmable light. 90005 90002 90003 Osram 90004 90047 Osram Sylvania’s 60-W equivalent LED bulb is notable in that it has a relatively small, two-piece heat sink.One piece is a 1-in.-high pentagon-shaped tower that doubles as a backing for six LED boards, five oriented in a pentagon shape with the sixth sitting atop the pentagon tower. The other is a 0.75-in.-long cylindrical cast heat sink that apparently snap-fits to the upper part of the plastic dome housing the LEDs. The cylindrical cast heat sink and tower together weigh 1.3 oz. 90005 90049 90002 A view of the Osram LED bulb with its plastic globe cut off revealing the pentagon-shaped tower holding the LEDs.The wires from the ac / dc converter board can be seen soldered to the top plate. 90005 90002 The base of the unit is a one-piece plastic housing that holds the ac / dc converter circuit board. Two wires connect it to the pentagon-shaped tower holding 18 LEDs, three on each face. The connections between the boards appear to have been reflow soldered. But the discrete wires between the circuit board and the LED assembly appear to have been hand soldered. Similarly, connections to the bulb base are discrete wires with one squeezed between the metal screw threads, the other a machine assembled to the bulb foot.90005 90054 90002 The potting material surrounding the Osram bulb’s ac / dc converter board and the plastic case from which it was extracted. 90005 90002 For reasons that are not completely clear, the designers of the Osram bulb chose to pot the ac / dc converter board. The relatively small heat sink in this board, compared to other designs we’ve seen, might indicate the potting is meant to improve thermal dissipation, though potting material does not completely fill the empty space between the electronic components and the external shell.The potting did, however, complicate the process of deciphering the circuit. 90005 90059 90002 The SSL21082AT reference circuit seems to be close to what we found on the Osram PCB. The chip has an input for a NTC resistor, but we did not spot one on either the PCB or the metal plates to which the LEDs mount. 90005 90002 The main board for the Osram LED bulb is two sided. It contains two ICs, one a diode bridge for the ac input, the other an SSL21082AT driver IC from NXP Semiconductors. Features implemented on the NXP chip include dimming, over-temperature protection and LED over-temperature control, output short protection, and a restart mode in the event of a brown out.This IC has an integrated internal HV switch and work as a boundary conduction mode (BCM) buck converter. 90005 90064 90002 The main heat sink for the Osram LED bulb is a cylindrical casting, shown here in four pieces after removal from the body of the bulb. The metal screw threads attach to the plastic case holding the ac / dc converter board, visible here. 90005 90002 BCM is a quasi-resonant technique used to enhance energy efficiency. The fundamental idea of ​​BCM is that the inductor current starts from zero in each switching period.When the power transistor of the boost converter is turned on for a fixed time, the peak inductor current is proportional to the input voltage. The current waveform is triangular; so the average value in each switching period is proportional to the input voltage. 90005 90069 90002 Once the potting material was removed from the Osram bulb’s PCB, the SSL21082AT driver IC from NXP Semiconductors became visible on the PCB. The other IC on the board is a bridge rectifier. Energy handling capacitors and inductors are mounted to the other side of the board.90005 90002 90073 90005 90002 90076 90005 90002 Energy stores in the inductor while the switch is on. The inductor current is zero when the MOSFET is on. The amplitude of the current build-up in the inductor is proportional to the voltage drop over the inductor and the time that the MOSFET switch is on. When the MOSFET is switched off, the energy in the inductor releases toward the output. The LED current depends on the peak current through the inductor and on the dimmer angle. A new cycle starts once the inductor current is zero.90005 90002 90003 3M 90004 90047 The 3M LED has a distinctive look thanks to the 2-in.-high white cylindrical column visible under its semitransparent plastic dome. The column is just a metal heat sink; it apparently has nothing to do with the dispersion of light. 90005 90085 90002 The 3M LED bulb with the plastic globe removed. The white column is a heat sink and has little effect on the light output. The LEDs are positioned around the rim of the plastic bulb in the metal heat sink. 90005 90002 The LEDs sit on a flex circuit board attached to another 2-in.-high heat sink that also forms a support for the base of the bulb. A plastic sleeve goes on the bottom of the heat sink to hold the metal screw threads and support the foot contact at the bottom of the base. The heat sink plus column together weigh in at 2.4 oz. 90005 90090 90002 The 3M bulb base consists of a plastic sleeve around the heat sink to which the metal threads and foot contact mount. The electrical connections are on the flex circuit holding the LEDs and ac / dc converter. Visible here are the contact that bends over the side of the plastic sleeve to make contact with the metal screw threads, and a second contact that touches a post on the foot contact (right).90005 90002 The flex circuit board holding the LEDs also holds the ac / dc driver circuit. It is a CL8800 from Microchip Technology. The reference design consists of the CL8800, six resistors and a bridge rectifier (a Fairchild device). Two to four additional components are optional for various levels of transient protection. Microchip’s reference design is quite close to what we found in the 3M bulb. 90005 90095 90002 The reference circuit for the Microchip CL8800 is close to the circuit found on the 3M LED bulb, though the 3M bulb includes an additional RC network (not shown here) for phase dimming.90005 90002 The driver circuit divides a string of 25 LEDs into two sets of five, one set of four, and one set of six. We’re not sure why 3M divided the number of string LEDs this way. Their orientation, however, is interesting. They sit on a ledge formed by the heat sink and are oriented straight up. The transparent carbonate globe fits onto the same ledge, so the LED light output is actually up into the edge of the plastic globe itself, rather than shining through the globe from the inside of the shell.90005 90100 90002 A close-up of the flex circuit on the 3M LED bulb that holds both the ac / dc converter circuitry and the LEDs 90005 90002 The LED driver circuitry is quite simple and laid out on the flex circuit without any potting compound to get in the way. According to the Microchip data sheet, six linear current regulators sink current at each tap and are sequentially turned on and off in a manner tracking the input sine wave voltage. The chip minimizes the voltage across each regulator when conducting, providing high efficiency.90005 90002 90106 90005 90002 The output current at each tap is individually set by a resistor. An RC network, consisting of a resistor and three capacitors in parallel, on the input of the bridge rectifier provides phase dimming. Two other components handle transient protection on the connection to the ac line. In all, there are 13 discrete components on the flex circuit that make up the transient protection, phase dimming, and set the currents in the LED strings. 90005 90002 90003 Feit Electric Co.90004 90047 The bulb from Feit Electric had the oddest orientation for LEDs of any we examined. The 1 7/8-in.-diameter plate onto which the 36 LEDs mount is partly hidden in the assembled bulb by a circular plastic piece with a 1-in.-diameter hole in the middle. This piece mounts over top the LED plate. So, a look at the assembled bulb provides a view of the plastic piece and just five LEDs visible on the center of the plate below the hole in its middle. 90005 90115 90002 Potting material on the Feit bulb’s PCB, visible here at the base of the heat sink, doubled as a structural element holding the foot contact in place.90005 90118 90002 Three screws held the LED plate to the heat sink on the Feit LED bulb. The reverse side of the LED plate, visible here, had thermal compound applied between the heat sink and LED plate surfaces. 90005 90002 We are at a loss as to why Feit installed the plastic piece over top most of its LEDs. The piece blocks most of the light they emit. (We have no way of quantifying the amount of light getting through the plastic. But informal tests here indicate little of it penetrates.) So the vast majority of the emitted lumens come from the five LEDs in the center of the plate. 90005 90002 90124 90005 90126 90002 The Feit LED bulb positioned a plastic disk over all but five of its 36 LEDs. We’re not sure why. 90005 90002 The rest of the bulb’s mechanical design is less mystifying. The LED plate mounts to the top of a hefty 3.8-oz cast metal heat sink with three screws. The heat sink serves as the main body of the bulb. The ac / dc converter circuitry fits in a plastic cylinder that slides into the base of the heat sink and attaches to it with two screws.90005 90131 90002 With the potting material milled off, the PCB for the Feit LED bulb revealed a diode bridge IC and SSL2103T LED driver from NXP Semiconductors on one side, large energy storage elements and power MOSFETs on the other. 90005 90002 The electronics is potted into the plastic cylinder that serves as its housing. The potting material is extensive, filling the cylinder. It also doubles as a structural element supporting the screw base of the bulb and the contact foot. The circuit board holding the electronics is two-sided and extends back nearly to the foot of the bulb base.The negative lead to the board is held to the metal screw threads by the potting material. Two wires run from the board to the LED board and seem to be hand soldered there. The board itself is reflow soldered. 90005 90002 The potting material obscured some of the details on the PCB, but on the board are two power MOSFETs, a diode bridge chip, five large caps, transformer, and at least 22 discrete components comprised of resistors, small caps and diodes. The input bridge rectifier seems to be protected with a fusistor.90005 90002 The main chip is an SSL2103T LED driver from NXP Semiconductors. The SSL2103 is basically a flyback converter that operates in combination with a phase cut dimmer circuit directly from the rectified mains. It implements dimming through integrated circuitry that optimizes the dimming curve. Drive outputs are available for resistive bleeder switching. 90005 90002 Though potting material obscures some of the connection details, the circuit seems to be close to that of NXP reference designs for the chip.The mains voltage is rectified, buffered and filtered in the input section and connected to the primary winding of a transformer. The transferred energy is stored in a capacitor and filtered before driving the LED chain. 90005 90002 The circuit board also includes two power MOSFETs. One seems to be part of a dimming circuit that divides and filters the mains rectified voltage to provide an input for the generation of the dimming curve. A bleeder drive output from the NXP chip drives the MOSFET to switch bleeder resistors that are involved in a timer for the dimming function.The other MOSFET is the main switch for the flyback transformer. 90005 90144 90002 The Feit ac / dc converter circuit was close to the reference circuit the NXP Semiconductors provides for its SSL2103 converter. 90005 90002 There is also a buffer circuit consisting of two capacitors and an inductor. The circuit stores energy to ensure the converter can transfer power continuously to the LED chain despite any mains power fluctuations. It also filters ripple current generated by the converter to keep down any mains-conducted emissions.90005 90002 Finally, another portion of the circuit consists of a capacitor, a rectifier diode, a peak-current-limiting resistor and a protection zener diode and is used to generate an external VCC supply for the IC. 90005 90002 90003 Philips Lighting Co. 90004 90047 One noteworthy point about the Philips bulb pertains to heat sinking. The other bulbs we examined had metal heat sinks ranging in weight from 1.3 to 3.8 oz. The Philips bulb manages to handle thermal issues without any extra heat sinking.The only component that spreads heat is the 2.5-in.-diameter disk onto which the 26 LEDs mount, 13 to a side. Moreover, you might expect that designers would stagger the LEDs on the disk such that they would not mount directly opposite each other-this mounting arrangement would also help spread heat. But the LEDs on either side of the disk sit directly opposite each other. It appears that LED heat just was not an issue in this design. 90005 90002 One of the reasons why is the presence of a negative temperature coefficient (NTC) thermistor on the LED board.But it proved to be impossible to trace out the temperature compensation network exactly because the driver PCB has three layers, one hidden. Further complicating the analysis of the circuit is the fact that two six-pin ICs seem to handle the ac-dc conversion and neither is marked with either a manufacturer logo or part number. 90005 90002 Because the main ICs can not be identified, we can only hypothesize about how the LED driver works. The presence of a transformer, two large capacitors and an npn power transistor (from STMicroelectronics) on the PCB would seem to indicate that the converter has a flyback design.Our guess is that the temperature compensation network is in the biasing of the switch providing current to the LEDs from the flyback transformer. Two transistors seem to handle the LED current. In all, we counted 32 small discrete components made up of resistors, diodes and capacitors. Rounding out the board components were a bridge rectifier chip and three other power capacitors. 90005 90160 90002 The Philips LED bulb had no heat sink other than the two-sided plate holding the LEDs. One reason: temperature compensation.The NTC resistor is visible on this shot of the LED plate. 90005 90002 It turns out that the mechanical design of an LED bulb that contains no heat sink can be quite simple (and some might call it elegant). The Philips bulb is basically a plastic enclosure that encases the LED plate and driver PCB while also supporting the metal screw threads and contact foot. 90005 90165 90002 The diode bridge and npn power transistor is visible on one side of the Philips LED bulb PCB. The other side holds the energy storage components and the two unidentified ICs providing temperature compensation, dimming and power conversion.90005 90002 The form factor differs from that of other bulbs because of the two-sided LED plate. The Philips bulb is not so much a bulb as a disk. Rather than encasing the LEDs in a transparent globe-like enclosure, the Philips device presents a flat profile with plastic encasing the two-sided LED plate. The enclosure seems to just snap together over top the LED plate and driver PCB. 90005 90170 90002 There is not much to an LED bulb when it can be built with no heat sink. The Philips bulb basically consists of the PCB and LED plate along with the snap together plastic case which also supports the contact foot.90005 90173 90002 The foot contact attaches to the PCB on the Philips bulb with wiring, visible here. The contact with the metal screw threads is via a wire that squeezes between the threads and plastic enclosure. 90005 90002 And because the Philips bulb contains no heat sink, it is quite light weight. But its disk-like outline might look a little weird to consumers accustomed to screwing things that are shaped like spheres into light sockets. And it beams most of its light out on the two sides defined by the orientation of the LED plates.It relies on diffusion by the plastic enclosure for lighting in other directions. 90005 .90000 LED FAQs | LED Lighting 90001 90002 What does LED stand for? 90003 90004 LED is short for light-emitting diode. 90005 90002 How long do LEDs last? 90003 90004 LEDs are notable for being extremely long-lasting products. Many LEDs have a rated life of up to 50,000 hours. This is approximately 50 times longer than a typical incandescent, 20-25 times longer than a typical halogen, and 8-10 times longer than a typical CFL. Used 12 hours a day, a 50,000 bulb will last more than 11 years.Used 8 hours a day, it will last 17 years! 90005 90002 Where can LEDs be used? 90003 90004 They can be used almost anywhere. LED replacements are already available for bulb types such as A-shape, PAR reflectors, MR reflectors, decorative, undercabinet, and more. When used on dimmers, particularly dimming systems that support many bulbs, we suggest testing a few LEDs first to test compatibility. 90005 90002 Should LEDs be used in enclosed fixtures? 90003 90004 Enclosed fixtures are defined as not only air tight, but also are fixtures that are enclosed on the side, rear and open in the front, such as many track heads.LEDs that are used in fixtures where there’s less than 1/2 «around the circumference of the lamp when installed in the fixture are also considered an enclosed application. If you plan to use LEDs in these types of applications you should use an LED that’s rated for enclosed fixtures. Using an LED lamp not rated for enclosed fixtures in this type of application may cause the LED lamp to flicker and will dramatically reduce the life of the lamp. 90005 90004 Bulbs.com now offers a wide assortment of enclosed rated LEDs in many different lamp shapes.LEDs not rated for enclosed fixtures should only be used in fixtures open in the front, where the lamp’s lens is open on the sides and the rear, and should have at least 1/2 «space around the circumference of the lamp. 90005 90002 What are the advantages of switching to LED? 90003 90004 The advantages of switching to LED are numerous. Here are just some of the benefits: LEDs use much less electricity than other bulbs, have extremely long rated lives, produce very little heat, do not emit UV or infrared, contain no mercury, are resistant to shock and vibration, and can operate effectively in extremely cold environments.For more information the advantages of LED, see LED: Is It Right For You ?. 90005 90002 Why do LEDs cost more than other types of bulbs? Are they worth it? 90003 90004 LED is still a new technology, and the expense of producing quality product is still high. However, pricing has come down dramatically from just a few years ago and prices are expected to continue to drop. In terms of whether LEDs are worth the extra cost, it’s helpful to look at the cost to operate a bulb in addition to the up-front cost.The energy savings realized in a switch to LED means that the extra up-front cost is often paid back rather quickly, and you’ll wind up saving money over the life of the bulb. If you’d like to see this in action, check out our Energy Savings Calculator. Here is an example: for a residential customer who may have the light on for just 10 hours per week ñ the payback is over 10 years. On the other hand, a retail or restaurant client who is burning lights for 90-100 hours per week will calculate their payback on a $ 70 LED PAR to be less than 18 months.Taking a look at your payback estimate should definitely be a consideration when deciding if LED is right for you. 90005 90002 Is there really any difference between a $ 10 LED and a $ 50 LED? 90003 90004 Yes. LEDs are very similar to consumer electronics and quality really matters. In order for an LED to function properly and provide an acceptable light output, all of the components must be built to last. It’s always a good idea to buy from a manufacturer and retailer that you’re confident will stand behind the product.If you’d like to learn more about the components and how cheaply-made LEDs stack up against top-quality product, check out A Tale of Two Bulbs. 90005 90002 Is an LED going to produce enough light to replace my current bulb? 90003 90004 For most applications, yes. Off-the-shelf LED products are now reliably replacing incandescent equivalents of up to 100 watts, and specialty products are available to replace even higher wattages. If you’d like to learn more about LED light output, take a look at this article on light output.90005 90002 What’s the quality of LED light? 90003 90004 If you buy quality product, the light quality is excellent. Color Rendering Index (CRI) is generally used to measure light quality on a scale from 1-100. Most LEDs have a CRI rating of at least 80, and many are rated 90 and above. 90005 90004 CRI 90005 90004 Color Rendering Index is an international system used to rate a lamp’s ability to render object colors.The higher the CRI (based upon a 0-100 scale) the richer and more accurately colors generally appear. CRI differences among lamps are not usually visible to the eye unless the difference is more than 3-5 points. 90005 90004 90005 90002 How green are LEDs? 90003 90004 LEDs are very green. For starters, they use much less electricity than many other lighting products. This means that less electricity has to be produced to operate them, and resulting in lower emissions from power plants, especially in areas where coal-fired plants are common.Unlike CFLs, they contain no mercury. Because of their long life, they also reduce solid waste: If you replace an incandescent bulb with an LED, you will prevent fifty 1,000 hour incandescent bulbs from being thrown away. Additionally, they produce very little heat and can reduce energy usage related to HVAC. The U.S. Department of Energy has estimated that increased adoption of LEDs over the next 15 years would also reduce electricity demands from lighting by 62 percent, prevent 258 million metric tons of carbon emissions, and eliminate the need for 133 new power plants.90005 90002 Can LEDs be used with dimmers? 90003 90004 Usually, yes. Many LEDs are specifically listed as being dimmable. Some dimming systems work with LEDs better than others, so it’s best to test one or two before completely re-lamping a space. 90005 90002 Are there rebates / incentives / tax credits available for switching to LED? 90003 90004 In many cases, yes. In order to find out if you are eligible for a rebate or other incentive program, you can reference the Department of Energy’s DSIRE site, or call a Bulbs.com Lighting Specialist. 90005 .