Fixed LED Lights

    Recently, it has become fashionable to use LED lamps ( LED , Light Emitting Diode). The main reasons are energy saving (increased light output at the same energy consumption), environmental friendliness (harmful materials like mercury can be eliminated in production). To save energy, LED lamps so hit other types of lamps that some countries prohibit the production and sale of traditional incandescent lamps used for home and office. Most likely, something similar will happen over time in Russia. The purpose of this review is to figure out what LED lamps are, what parameters they have, which lamps are best to buy for organizing home lighting.

    I will not compare LED lamps with other light sources, just try to compare some LED lamps with each other. The review also did not include lamps with built-in dimmers (lamp brightness level controls) and lamps with a standard socket that can be screwed into a cartridge instead of a conventional bulb (there are also such LED lamps). I wanted to explore some parameters of LED lamps on my own - electromagnetic interference and flickering of light (manufacturers do not provide objective information of this kind). I hope that the review will be useful to those who think about using LED lamps at home.

    Obviously, LED bulbs should generate radio interference, because each one has a pulse controller. The controller operates at frequencies of the order of 50..85 kHz, but due to sudden voltage drops at the key node of the controller, an electromagnetic signal with a wide spectrum is obtained. There is no specific information on the level of interference anywhere. In the instructions for the lamp, you can read abstract phrases such as "The product is certified according to current GOSTs." But what does this really mean? How strongly do these lamps generate interference, and how different brands of lamps differ from each other in this parameter? It is impossible to compare different lamps in terms of interference without special experiments, so I decided to be puzzled by this too.

    In addition, the LED has a very high speed, that is, it turns on and off almost instantly. The current supplying the LEDs has ripples due to the construction of the controller. For reasons of production cost, the filter for smoothing ripples cannot be made ideal, therefore, the LED lamp will necessarily flicker. The less the pulsation of the light flux, and the higher the pulsation frequency, the more subjectively the LED lighting will be better, the eyes will be less tired. The flicker intensity and its nature depends on the implementation of the controller. I also want to explore this.

    [ What lamps are involved in the review ]

    Managed to acquire lamps from Ecola companies (Russia, Moscow), Navigator(BT-Logistic LLC, Moscow, Russia), BBK (BBK Electronics LTD., China), Jazzway (like a Russian company, but where it is located, could not be determined), Gauss (Russia, Naberezhnye Chelny) , ASD (ASD Lighting, UK). All lamps had caps type GU5.3 and GU10, incompatible with traditional lamp base caps. The photographs below show these socles. The distance between the pin axles of the GU5.3 cap is 5.3 mm, and for the GU10.3 10 mm.

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    [ How the light level was measured ]

    I was not able to make all measurements exactly as recommended by standards [1]. Therefore, I tried to put the lamps in the same conditions: I turned the test lamp into a ceiling lamp with a lampshade and measured the level of illumination at the workplace where I was sitting at a computer. Illuminance was measured with a Lux Meter LX1010BS luxometer .

    Appearance Lux Meter LX1010BS
    Lux Meter LX1010BS

    118 lux - illumination at the workplace during the day with the ceiling lights off. 400..1000 lux - a sunny day in the shade, a well-lit workplace. In my tests, the lighting turned out to be about 60.100 lux - I wrapped the test lamp in the upper ceiling lamp and installed the luxometer at some distance from the lamp so that the main direct light beam would not fall on it.

    [ Comparison of the lamps by the level of electromagnetic interference ]

    I did not have a radio frequency spectrum analyzer, so I checked the noise by ear using the Leningrad-006 radio receiver, on the HF and VHF bands.

    Radio 'Leningrad-006'
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    The radio stood with an extended whip antenna at a distance of 1 meter from a working lamp. Each lamp received a conditional estimate of the interference level from 0 to 10 (0 interference was not detected, 10 maximum interference level), and these data were listed in table 2.

    [ How to estimate the ripple of the light flux ]

    I used a solar battery from the country lamp.

    Solar battery as a light pulsation sensor
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    I loaded the battery onto a 180 ohm resistor and connected it to an oscilloscope. As it turned out, an excellent light sensor was obtained, which confidently showed both low-frequency (100 Hz) and high-frequency pulsations (50..85 kHz). Interestingly, some lamps gave ripple at a frequency of 100 Hz, and some at high frequencies of 50..85 kHz.

    Examples of waveforms of pulsations of light of LED lamps
    LF ripple light bulb ASD JCDRC 7.5w:
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    HF ripple light (approx. 50 kHz) BBK P653F lamp:
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    You still won’t notice the pulsations of 100 Hz, but it may increase fatigue and visual beats may occur with the TV screen (many modern TVs also have a screen refresh rate close to 100 Hz). High-frequency light pulsations can affect the operation of remote control systems for household appliances. In addition, if several lamps with large pulsations of light at a high frequency illuminate the room, then pulsations of light that are visible to the eye may also appear due to the difference in the pulsation frequencies (the operating frequencies of the controllers are not synchronized with each other).

    Thus, you need to try to choose a lamp with a minimum level of pulsation of the light flux, at whatever frequency they may be.

    [ How I compared the lamps to each other ]

    Home Laboratory Stand
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    Power was supplied to the lamp just in case through an industrial surge protector (pictured left). I took the oscillograms of the input current of the controller using a current transformer from a ferrite ring. The pulsations of the light flux were monitored at the output of a solar battery loaded on a resistor (in the photo next to the Rigol DS1102C oscilloscope).

    First, I brought together in one table all the official data that I managed to collect about the lamps - price, power consumption, color temperature and other parameters that can be found on the lamp packaging. This table allows you to make a general preliminary assessment of the lamps. Cells in the table showing the best parameters among the remaining lamps are highlighted in green, and poor parameters in orange.

    Table 1. Parameters of LED lamps provided by the manufacturer.


    The most important parameters that can be distinguished in the table are the price of the lamp, luminous flux and power consumption. Their ratio determines how effective the lamp is. I did not take into account the service life, since it cannot be checked, and the actual service life will vary greatly from the operating conditions. To evaluate the efficiency of the lamp, I calculated the conditional efficiency coefficient K:

    K = Light / (Price * Pow)

    In this formula, Light means luminous flux (Lm, the higher the luminous flux, the brighter the lamp shines), Price is the price (rubles, the cheaper the lamp, the faster it will pay for itself), Pow is the power consumed by the lamp (W, the smaller the lamp consumes electricity, the more profitable it is). This coefficient K rather roughly evaluates the lamp efficiency, because the luminous flux strongly depends on the presence of a reflector (the angle of the light beam), and many other factors have not been taken into account (regulator efficiency, lamp life, workmanship, etc.).

    The second table was compiled on the basis of experimental data. The table includes the measured level of illumination, the level of radio noise, ripple of the light flux and other data. Cells in the table showing the best parameters among the remaining lamps are highlighted in green, and poor parameters in orange.

    Table 2. Experimentally obtained parameters of LED lamps.


    The line “Illumination” shows the illumination in the suites, which was shown by the luxometer at my workplace (the lamp was installed in the ceiling lamp). Of course, for full lighting of the whole room, one 6..7-watt LED lamp is not enough.

    The efficiency of the controller was calculated by the traditional method:

    efficiency,% = 100 * (Pout / Pin)

    In this formula, Pout means the output power supplied by the controller (product of the measured current and voltage), and Pin means the power supplied to the controller's input (product of the measured input current and input voltage). Please note that some of the lamps in the review had a very low controller efficiency - about 40%, which seemed very strange to me. Subsequently, it turned out that for these lamps the “controller” was built according to the simplest scheme - on the basis of a quenching capacitor (for more details see [4]). Not sure if you should buy such lamps.

    [ BBK ]

    I was surprised when I found out about BBK as a lamp manufacturer, because before, I only had to deal with BBK home appliances like DVD players or media centers. The 4 BBK lamps included in the review have a high-quality base for a GU10 holder made of white heat-resistant plastic (looks like ceramic) and an aluminum radiator.

    Lamp BBK P653F, photo
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    Lamp BBK P654F, photo
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    Lamps P653F and P654F have less power and consist of 32 separate LEDs located on the same plane, at some distance from each other. Therefore, the P653F and P654F lamps give more diffused light with a beam angle of 120 o .

    Lamp BBK PC73C, photo
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    Lamp BBK PC74C, photo
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    Лампы PC73C и PC74C снабжены рефлектором, концентрирующим свет от сложного многосегментного светодиода (состоит из матрицы 5x7 излучающих элементов), поэтому они дают узкий пучок света с углом расхождения около 60o. Радиатор лампы имеет температуру 45..65 oC.

    Лампы BBK выглядят лучшими из всех в плане конструкции и исполнения. BBK не единственные в обзоре, которые имеют честный алюминиевый радиатор, но у BBK радиатор изготовлен наиболее качественно и имеет много охлаждающих лепестков. Поверхность радиатора имеет следы обработки на токарном и фрезерном станке, а это довольно дорогая операция. Уж и не знаю, как изготавливали лампы, однако на потребительскую цену это повлияло незначительно (см. таблицу 1).

    The color temperature of the lamps, as far as I can figure out, depends on the color of the compound with which the light-emitting LED elements are coated. The yellower the compound, the lower the color temperature.

    The lamp controllers P653F and P654F are built on the basis of the SM7525 chip , while PC73C and PC74C lamps are based on the BP9023 chip[4]. In terms of radio interference, the PC73C and PC74C lamps did not perform well (see table 2). The P653F and P654F lamps have a low, almost imperceptible level of radio interference. The level of pulsation of the light flux for all BBK lamps is very low (about 8..9%) and lies in the high-frequency spectrum, invisible to the eye (about 55 kHz). Of these lamps, I would choose the P653F and P654F lamps for myself. An additional plus for BBK bulbs - there is an additional 3-year guarantee on the brightness of the light flux, which none of the other brands have.

    [ Navigator ]

    Lamp Navigator NLL-MR16 3K GU5.3, photo
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    Lamp Navigator NLL-PAR16 4K GU10, photo
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    The design of the lamps is the cheapest - a cast housing made of grayish plastic, there is no cooling radiator. The NLL-MR16 3K lamp fell apart right in my hands when I tried to make contacts in the GU5.3 socket.

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    The controller for the Navigator NLL-MR16 3K GU5.3 lamp is built on the BP2832A chip [4]. In terms of radio noise everything is fine, the lamps are “quiet”. With pulsations of light, too, everything is fine. The least ripple of a NLL-MR16 3K lamp. The Navigator NLL-PAR16 4K GU10 lamp controller is based on the NXT chip SL21083 [4]. The NLL-PAR16 4K lamp has slight ripples of light at a frequency of 86 kHz, but they can only be noticed by the infrared control system of the TV.

    If not for the lack of a radiator, Navigator lamps would be a good choice.

    [Ecola ]

    The Ecola 6w 2800K GU5.3 is equipped with a very high-quality aluminum radiator. Unfortunately, the lamp gives a high level of radio noise and a significant level of light pulsations at a frequency of 67.5 kHz, which can impair the operation of remote control systems for household appliances (see table 2).

    Lamp Ecola 6w 2800K GU5.3, photo
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    Lamp Ecola 7w 4200K GU10, photo
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    The controller is built on the chip BP3122 [4].

    How it is arranged inside the Ecola 7w 4200K GU10
    Under the protective diffuser is a printed circuit board with 14 LEDs installed in series. Since the controller generates a voltage of 81 volts on the LED chain, then each LED is for sure doubled (inside each “LED” there are 2 LED elements connected in series). The LED board transfers heat to the aluminum radiator through thermal grease.

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    The lamp controller is built on the Chinese chip BP2831A . The circuit diagram is amazingly simple. Resistors RS1 and RS2, connected in parallel, are used to adjust the current through the LEDs.

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    The controller is placed directly in the lamp base, all the external conductors of the controller are made as short as possible. Perhaps this explains the complete absence of electromagnetic interference?

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    Below are the waveforms of the input AC current that comes from the 220 V network.

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    And this is the waveform from the output of the solar battery. Absolutely no ripples of light, neither high-frequency nor low-frequency!

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    Unfortunately, for Ecola lamps, the manufacturer gives only a year of warranty, which raises doubts about the long life of the lamps.

    [ Jazzway ]

    These lamps, like the BBK, also have a full aluminum heatsink, but they look simpler. For a 2700K lamp, the radiator has through grooves that improve air circulation, while for a 3000K lamp, the radiator has a large number of fins. The lamp base type GU10 is made of heat-resistant white plastic. The 3000K lamp has a complex multi-segment emitting LED with a diameter of 33 mm (this is the largest “LED” among all the lamps in the review). The number of emitting segments of the 3000K lamp could not be determined, since they are hidden by a yellow compound. The 2700K lamp has 17 separate LEDs located on the same plane.

    Lamp Jazzway 7.5w 2700K GU10, photo
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    Lamp Jazzway 7.5w 3000K GU10, photo
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    In terms of radio noise, the 2700K and 3000K lamps differ significantly (see table). The 2700K lamp is “quiet” and the 3000K “phonite” on all radio bands. This is probably due to the features of the controller implementation.

    The 2700K lamp gives very strong pulsations of the light flux with a frequency of 100 Hz (dips about 85% of the maximum radiation). This is not surprising - the lamp does not have a controller, a simple capacitor 12 uF 400V is used as a current limiter [4]. The 3000K lamp has a full controller on board the LIS8512 chip [4], and the 3000K lamp has such small pulsations of light that it is impossible to evaluate them, that is, this lamp gives stable, flicker-free light (if only it didn’t give radio interference like a lamp 2700K, she wouldn’t have a price).

    It is difficult to say which of these two lamps to choose. If you take care of your eyes, it is better to take a 3000K lamp, if you are a ham radio amateur, then it is better to 2700K. Keep in mind that the use of a large number of lamps with a quenching capacitor (like a 2700K lamp) will degrade the supply network due to a phase shift between current and voltage.

    [ Gauss ]

    The lamp has a metal radiator, the base is made of heat-resistant plastic, it looks very decent from the outside. Packaging and instructions are made very high quality, as if it was not a lamp, but a piece of jewelry.

    Lamp Gauss EB101106107, photo
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    Radio interference on HF is not seen, on VHF are present. There are large ripples of light at a frequency of 100 Hz.

    IMHO the lamp does not stand out anything special, except for quality packaging and unreasonably high prices.

    [ ASD ]

    In appearance and design, the ASD JCDRC 7.5w lamp is exactly the same as the Jazzway 2700K. The same case, the same aluminum radiator, the same dimensions, the number and arrangement of emitting LEDs, even the parameters are almost the same, only the color temperature of the light is different. The ASD JCDRC 7.5w and Jazzway 2700K lamps are so similar that they seem to be made on the same conveyor, they just have different labels and use different packaging.

    Lamp ASD JCDRC 7.5w, photo
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    In terms of radio noise and pulsations of the light flux, everything coincides with the Jazzway 2700K lamp. There is no radio interference, but the flickering of light is large, at a frequency of 100 Hz. The reason for the ripple - instead of the controller, a 12 uF 400V capacitor was used as a current limiter.

    [ Conclusions ]

    1 . When buying lamps, you should pay attention to the type of cap and the length of the lamp, because this affects the ability to install the lamp in the place where it will be used.

    2 . If you need to connect a lamp with a GU5.3 or GU10 cap to a regular cartridge, you need to take care of purchasing an adapter (adapter).

    What the GU5.3 and GU10 Adapters Look Like
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    Please note that with the adapter, the total length of the lamp will be longer, and it may not fit in the lamp shade. The photo below shows the BBK PC74C lamp installed in the lampholder.

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    3 . If the declared angle of the light beam of the lamp is about 60..70 degrees, then for sure it is a lamp with a reflector, with a bunch of LEDs or with one LED. In my opinion, such a lamp has limited use, because it needs a special light diffuser. If the angle of the light beam is of the order of 120 degrees, then the reflector is absent, several light emitting diodes emitting light at a certain distance from each other emit light. It is possible that such a lamp also uses a light diffuser (a matte translucent cover that covers the LEDs).

    4. Color temperature indicates the color of the glow of the lamp. The lower the number of color temperature, the closer the color shifts to yellow, the higher - the closer to white and light blue. For example, 2700..3000K corresponds to soft yellow light, which is close in spectrum to ordinary incandescent lamps (I like such warm lighting more), and 4000..4500 correspond to white light (like fluorescent lamps).

    5 . To install the lamp, the GU10 base is most reliable, it does not require additional mounting of the lamp housing (although additional mounting does not hurt). Unlike GU10, the GU5.3 cap does not provide reliable lamp mounting. Therefore, it is impossible to use the lamp with the GU5.3 cap without additional fastening; the lamp can simply pop out of the holder.

    I really did not like the GU5.3 cartridge, despite the fact that it is compact. The GU5.3 contacts are unreliable, and it’s rather difficult to install the lamp (it’s hard to get pins into the sockets) - if you compare the cartridges of the GU5.3 and GU10 adapters with each other. The GU10 holder, on the other hand, is very convenient, the lamp is easily inserted and removed, and holds in the holder securely.

    6 . Some LED lamp models may generate strong radio frequency interference. Therefore, if your activity is related to radio reception or accurate laboratory radio engineering measurements, then pay special attention to the choice of lamps and install additional filters.

    7. If there are no special requirements for the size of the LED lamp and you are not constrained in the means, then give preference to lamps with a metal cooling radiator. The LEDs in them will last longer, because the temperature regime of the LEDs is better, they heat up less during operation. If possible, do not use fully enclosed fixtures for LED lamps, where the flow of cold air is difficult to the lamp. Try not to buy lamps without an aluminum radiator, especially with a power of 7 watts or more.

    8 . Be careful with the working LED lamps, do not look at their radiating surface. Pay special attention to lamps that have reflectors (with a narrow angle of the light beam) - you will easily catch bunnies in your eyes!

    [ UPD140725 ]

    At the request of the workers, he added a color rendering index Ra to table 1 , aka CRI [3] (this parameter was not found for all lamps).

    [ Links ]

    1 . GOST R 54350-2011 - measurement of the parameters of LED light sources .
    2 . LED lamp .
    3 . Color Rendering Index - Wikipedia .
    4 . The internal structure of LED lamps - circuit diagrams, oscillograms of current consumption, light flux.

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