In January 2020, the first LED lamps went on sale using Sunlike LEDs, providing a uniform spectrum without peaks and perfect color rendering.
About Sunlike Technology from Korean Seoul Semiconductor i told back in 2018.
Conventional LED lamps use LEDs with crystals that emit blue light. The crystal is coated with a two-component phosphor that converts blue light into white (one component adds the red part of the spectrum, the other adds green, and blue light seeps through the phosphor itself). Sunlike LEDs use crystals that emit violet light and a three-component phosphor that produces the red, green and blue part of the spectrum. This is less effective, but the spectrum is even and all colors are perfectly reproduced.
For comparison, the spectra of three LED lamps with a color temperature above 5200K: a conventional one with CRI 80, lamps with CRI 95 and lamps with Sunlike.
Two years ago, Sunlike LEDs were very expensive. That is why large companies did not try to make bulbs on them - few people are ready to buy one lamp for one and a half or two thousands of rubles (I note that one enthusiast from Belarus nevertheless set up handicraft production of lamps at Sunlikes, I wrote about it).
Now prices have dropped, and although Sunlike LEDs are still an order of magnitude more expensive than conventional ones, it became possible to start producing lamps with E27 and E14 sockets at affordable prices - from 350 to 399 rubles.
I am proud to be the first manufacturer in the world to launch such lamps under the brand Remez, became a Russian company (albeit with a legal entity in Germany). By the way, earlier the same company released table lamps based on Sunlike LEDs (I reviewed them: https://ammo1.livejournal.com/1013469.html).
Now 8 types of lamps with "solar" spectrum have been produced. These are "pears" A60 E27 with a power of 7 and 9 W and "candles" with an E14 base of 5 and 7 W. The lamps are available with two color temperatures of light - warm white light 3000K and cold white light 5700K.
A nine-watt lamp gives the same brightness as a 60-watt incandescent lamp, a seven-watt lamp shines like a 40-watt "Ilyich bulb", a 5-watt candle replaces a 30-watt incandescent lamp.
I have tested two of each of these lamps. The results of lamps showing slightly worse and slightly better characteristics are presented in two tables.
As can be seen from the results, the differences between the two specimens are insignificant (up to 7.5% in luminous flux).
All lamps have a low level of light ripple (0.5% or less).
All lamps have a very high CRI (Ra) (96-98) and high color rendering indices (R1-R15 - above 91).
Power, luminous flux, incandescent equivalent and color temperature are close to those stated.
All lamps, except for five-watt candles, work correctly with switches that have an indicator. Five-watt candles glow dimly when such a switch is turned off.
All lamps can work without decreasing brightness with a significant decrease in the supply voltage, in fact, they have a built-in stabilizer. Nine-watt lamps reduce brightness by 5% when the supply voltage drops to 129 V, the rest when it decreases to 113 V. This allows the use of lamps in areas with low and unstable voltage in the network.
Luminous flux, color temperature and color rendering index were measured using two-meter integrating sphere and spectrometer Instrument Systems CAS 140 CT, power consumption and power factor of the device Robiton PM-2, device ripple Uprtek MK350D. The minimum operating voltage, at which the luminous flux decreased by no more than 5% of the nominal, was measured using the device Lamptest-1, stabilizer Calm Instab 500 and LATRA Suntek TDGC2-0.5. To stabilize the parameters, the lamps were warmed up for half an hour before measurements.
Test results and spectra of 9W pears with warm and cold light:
Test results and spectra of 7 W "candles" with warm and cold light:
On the manufacturer's website laid out lamp test reports in Archilight laboratory. The luminous flux of a nine-watt lamp after 1000 hours of operation fell by only 0.9% and this is an excellent result, on the basis of which we can assume that the lamps will work for a long time. By the way, the manufacturer gives them a 5-year warranty.
The efficiency of conventional LED lamps with a CRI of around 80 has now reached 120 lm / W. For lamps on Sunlikes, it is much lower - 60-75 lm / W, but it seems to me that you can safely sacrifice efficiency for the sake of high-quality light. Yes, and 400 rubles per light bulb can be paid to achieve the ideal.
I expect that many will begin to lament that the brightest "pear" with warm light gives only 540 lumens, and the brightest "candle" 375 lumens. I can assume that the manufacturing company did not start producing more powerful lamps in order to prevent overheating and degradation of LEDs and to ensure a long service life. But why they released 7 W pears and 5 W candles is a mystery to me - they almost do not differ in price and most likely the majority will want to buy brighter 9 W pears and 7 W candles.
It's great that LED bulbs with perfect light have finally arrived. I do not really understand the decision of the manufacturing company to release lamps with a color temperature of 5700K, but I can safely recommend lamps with a warm light of 3000K to everyone.
P.S. Test results of Remez lamps on Lamptest.ru: lamptest.ru/search/#&brand=Remez.
© 2020, Alexey Nadezhin
The main topic of my blog is technology in human life. I write reviews, share experiences, talk about all sorts of interesting things. My second project - lamptest.ru. I test LED bulbs and help figure out which ones are good and which are not so good.