What are the LEDs in lamps (SMD). Dome LED lights AIX SMD IP44 LED smd luminaire
I ordered these diodes back in December 2013. In February 2014, already put in place. I did a review. Since then shine the bathroom. None burned out. I decided to experiment a little with the lamp. At the same time, let me remind you of a diagram with calculations on a ballast capacitor. Due to the simplicity of their execution, these schemes are of most interest to ordinary (and I consider myself one of them), people who are not gifted with special design talent.
It is on these drivers that most people ask for advice. Buy ready product the easiest. But to assemble a lamp almost from garbage is much more interesting. Moreover, a pleasant aftertaste remains in the soul from the fact that it was possible to put into practice something that had been lying around for years in a barn or garage :)
The package arrived fairly quickly, a little over a month. It could be worse. Unfortunately, this item is this moment not available. Time flows. Some stores disappear from the market, new ones appear. This store has sunk into oblivion.
The LEDs were packed in a paper bag, pasted over with "pimple" polyethylene from the inside. 
The seller is sociable, the parcel was thank you letter with a proposal for further cooperation. Even though it's in English, it's still nice.
LEDs ordered "warm", received exactly 500 pieces.
For the manufacture of the lamp, I used the classic "Chinese" scheme. Diodes are assembled in 4 parallels, 21 pieces each. Total 84 pcs. 
Soldering what I planned turned out to be a very tedious task. And if there is no good soldering iron (soldering station) - one torment. What he could, so he soldered. When I did everything, I realized that it was not so simple. It is necessary to take into account a small nuance. When soldering, the diodes need to be slightly offset. Otherwise, they can block the tracks with their pad. 
Soldering turned out not a fountain. But this homemade product has a special place. This is my very first experience in designing LED lamps. Yes, it looks ugly. But this is my story, and I will remember it. 
This product shines at the level of a 75W incandescent lamp. It was enough for the bathroom. 
At a voltage of 230V, the power is 7.6W. 
I have already made sure from my own experience that homemade products work much more reliably than purchased Chinese lamps. Did not for an exhibition, just experimenting. The board is double-sided fiberglass (from waste). Didn't poison anything. Just cut into right places grooves with a hacksaw blade stub. The rest of the parts are from old TVs. Only electrolyte and LEDs had to be bought. 
Everything was done in a hurry, for the sake of experiment.
Nothing is more permanent than temporary.Who said?..
And here is the formula by which the capacitance of the ballast capacitor C1 was calculated:
Uc - the voltage drop across the LEDs is obtained by multiplying the number of LEDs in one parallel by 3V (21x3 = 63V).
Iц - current, which we expect to let through the LEDs (but not more than the allowable one). Since there are 4 parallels, this value is multiplied by 4.
Let's say we want to run 10mA current through the LEDs.
10mA*4=40mA.
P = 0.04Ax63V = 2.52W - Estimated power of the panel.
And now let's calculate the capacity of the ballast: according to the first formula.
We get C1 \u003d 0.76 μF.
Conclusion: with a ballast capacitance of 0.82uF, the panel will shine brighter than a 25-watt incandescent lamp
These LEDs can handle up to 30mA (according to vendor information). Theoretically, the power of the panel can be increased by 3 times by changing the ballast capacity, but not forgetting about cooling.
The calculation is conditional, but it allows you to accurately calculate the power of the lamp.
I even checked. I measured the entire bunch of four capacitors with a multimeter. The device showed 2.254 microfarads.
Substituted in the formula (2). I managed:
Ic \u003d (230-63) * 2.254 / 3.18 \u003d 118.5 mA
P=118.5mA*63V=7464.8mW=7.46W
Taking into account losses on resistances and diodes, it turned out quite accurately.
At the expense of 0.1W (LEDs), the seller most likely made a mistake. Wherever you look, everywhere - 0.2W. Yes, and changed a lot, everything works.
The luminaire has good cooling due to large area. After an hour of work warmer hands. For three years, none of the LEDs shows signs of degradation. This is for skeptics. The area is 103 squares.
Finally, the hands reached the bathroom. I'm doing repairs. This lamp no longer fits into my design vision :) Therefore, I took it off. Will definitely use elsewhere. In the meantime, I decided to experiment (make fun).
But first, let me remind you about pulsations. According to smart books, pulsations above 300Hz do not affect overall visual performance. And we have very often 100 Hz. We must take into account. Therefore, we look at GOST R 54945-2012. There is a measurement scheme and a formula for calculation.
Then we look at the sanitary standards (SNiP 23-05-95 NATURAL AND ARTIFICIAL LIGHTING).
The document is voluminous. It is very difficult to extract the necessary information from it. I will help.
Depending on the purpose of the room, the maximum allowable ripple is from 10 to 20%.
Russian lighting standards establish that the depth of illumination pulsation at workplaces should not exceed 20%, and for some types of work 15 or even 10 percent. In fact, these are outdated indicators and for comfortable work for the brain (the eye does not perceive the pulsation and there is a load on the brain - fatigue and less productivity at the workplace), the pulsation should be no more than 4-5% absolutely at any workplace.And this information is for fans of incandescent lamps. They also have pulses. It all depends on power.
25W incandescent lamps have the thinnest spiral. And it has time to cool down during the transition of the current through zero. Therefore, the ripples are the largest (about 3%).
Light bulbs of lower power were not considered in principle. They are of little use in everyday life.
And this is already an “energy saving” 20W. It's a little worse here.
I got about 5%. But it fits into the rules.
No, this is not a driver issue. This is the problem of the small filtering capacity of the capacitor in the rectifier. The new light bulbs have a picture approximately similar, the ripples do not exceed the norm.
In cheap light bulbs, due to strong heating, the containers quickly degrade, turning the room into a laboratory for the effects on the brain.
It's time to watch my homemade.
I got 10% after three years use. It's too good for a bathroom.
I also measured the capacitance. I don't know how many were there originally. But 90uF remained.
I turn to the actual experiment. I decided to change the circuit a bit and see how it affects the ripples.
Scheme with half-wave voltage bifurcation :)
To smooth out the inrush current, but at the same time not affect the operation of the circuit, I replaced the usual input resistance with an NTC thermistor. I did about them. The thermistor will protect the LEDs at the moment of switching on from contact bounce, as well as the switch itself from burning the contacts at the moment the lamp is turned on.
NTC thermistors have a very good property, as the temperature increases, their resistance decreases. That is, at the initial moment they behave like ordinary resistance, decreasing their value with warming up. I also removed the features.
It may be easier for some to perceive in this form. 
One of the representatives of economical model of industrial LED lighting. The LED lamp is ordinary lamp, equipped with an optical system, a semiconductor crystal and a large number of built-in LEDs. LED bell light of this series, the most popular model for both outdoor and indoor lighting industrial premises. AIX SMD used for lighting warehouses, as well as industrial and domestic premises. The device has a domed type, equipped with a hanging mount on eyebolts of various lengths and a chain with a carabiner. The package includes the presence of various LED elements that provide effective lighting in diverse tasks. The degree of protection of the luminaire is IP44, which allows the use of this type of luminaires in rooms protected from moisture. The main two types are LED spotlight and industrial LED lamp. Thanks to a number positive characteristics industrial LED lamps have become the leader among lighting devices. The main plus of the dome luminaire is represented by low energy consumption compared to conventional lighting. LED lamp compared to the usual ten times reduces the level of electricity consumption. The device is safe for humans, there is no ultraviolet radiation and mercury in LED lamps, which can be harmful to human health. Another important advantage is a long service life, instant warm-up providing high-quality lighting from the first second.
High-quality LED products must work for at least one year. Hence the manufacturer's warranty of the specified period. Reliable lamps have a resource designed for years of work. Hence the longer warranty of trusted and conscientious manufacturers.
Wholesale price of 100W IP65 LED spotlight 3890 rubles
The price of a 100W LED lamp at retail is 4500 rubles
WARRANTY 5 YEARS.
Bulk lamp price:
4890 rubles 3890 rubles
Since the luminaires undergo the most stringent control system, the manufacturer is confident in their quality. Hence the warranty period for many products reaches up to 3 years. Projector.ru products are modern and highly reliable LED structures that have become the standard for lighting fixtures for industrial and other premises.
Wholesale price of 150W IP65 LED spotlight 5350 rubles
The price of a 150W LED lamp at retail is 6750 rubles
WARRANTY 5 YEARS.
Bulk lamp price:
5860 rubles 5350 rubles
LED dome lamps, with all their advantages, largely reflect the resource inherent in them. And it, in turn, is determined by the reliability of the manufacturer and the quality of the devices themselves.
Wholesale price of 200W IP65 LED spotlight 6350 rubles
The price of a 200W LED lamp at retail is 7870 rubles
WARRANTY 5 YEARS.
Lamp price:
6850 rubles 6350 rubles
Every industrial organization requires quality lighting. Industrial LED bell lamp AIX SMD used in factories production shops, construction sites, warehouses. This device provides a quality workflow. The luminaire increases the efficiency of the work team, which leads to increased productivity and at the same time saves on electricity.
Dome light LED has many advantages:
Convenient fastening;
- fashionable design; - ease of operation;- variety of models (different power);- high energy efficiency;- stable luminous flux, high-quality color rendering;- low energy consumption.To date a large number of manufacturers are ready to gladly offer their services for the acquisition, selection and installation of high-quality lighting. LED lighting has characteristic advantages over conventional lighting, which makes it the most demanded and necessary.
What are LEDs? The first LEDs were semiconductor light-emitting crystals, to protect them from external influences - water, dust, mechanical shocks, they were covered with a conventional case with a translucent cover. The conclusions in them perform several functions:
- connecting the light emitting crystal to the electrical circuit;
- mechanical fastening of the case.
The connection was made by soldering reverse side printed circuit board by passing the wire leads through the holes in the board. It was necessary to drill holes, manually bend the leads with tweezers, insert them into the holes, bend it 30-45 degrees on the reverse side, cut it with side cutters, leaving 2-4 mm, solder the lead and the contact pad. It was labor-intensive work with little possibility of automation.
The situation changed with the creation of SMD cases. This abbreviation appeared with the frequent use of the English phrase "Surface Mounted Device", which is translated into Russian as "devices for surface mounting".
The SMD type housing also performs communication and protective functions. The pins in it are not wire pins for passing through the board, but several contact pads on the sides of the case. The case is glued with a drop of glue to the installation site so that the contacts on the case coincide with the pads on the board. Then the connections are automatically or manually soldered.
What SMD LEDs are used for fixtures?
SMD cases are numbered, such as SMD 1206 or SMD 5050. These numbers indicate the dimensions of the case in tenths of a millimeter. So the housing of the SMD 5050 LED has dimensions of 5.0 x 5.0 mm. Not all 25 square meters are used to place LED crystals. mm of housing area, and approximately 20 - 22. Therefore, in such a housing, engineers managed to place three or even four light-emitting crystals and current-carrying elements in the early 2000s. Thus, superbright SMD 5050 LEDs white light, RGB, i.e. multi-color, as well as white RGBW types with four crystals - three color RGB crystals and one W-crystal - white, from White.
A variation of the SMD 5060 package is the same SMD 5050 package, but only taking into account the thickness of the contacts on the sides of the case.
There are two more types of LEDs - SMD 3528 and SMD 2835. Both cases have the same overall dimensions - 2.8 x 3.5 mm, and a total area of 9.6 square meters. mm. But in the old SMD 3528 LEDs the light-emitting crystal has a round shape with a diameter of 2.4 mm, which corresponds to a radiation area of 4.52 square meters. mm. In the new SMD 2835, the emitting element has dimensions of 3.0 x 2.3 mm, and an area of 6.9 square meters. mm, which is 67% more. The thickness of the phosphor was also reduced, so the value of the light flux increased.
A new version of the housing in SMD 2835 LEDs made it possible to more than double the area of contact pads. This allows you to "shoot" large quantity heat from the crystal, which means extending the service life or increasing the luminous flux.
Considering all of the above, the new SMD 2835 has tripled: luminous flux, rated operating current, power and forward current through the LED.
An example of a luminaire with these LEDs is an LED surface-mounted luminaire, model . High-brightness SMD 2835 LEDs with a total power of 6 watts are used. Luminous flux 450 lm.
LED SMD 1206 slightly falls out of the general idea of marking SMD LED cases. It has a 3.2 x 1.5 mm case. Operating current - 20 mA, brightness from 60 to 90 millicandelas.