Almost all of the LED lamps, which can be bought on the Aliexpress, very bad: many invalid pulsating light, low color rendering index, often the real power and luminous flux of up to five times less promised. I was convinced that Ali good lamp is not at all, but an exception is still found.
Last year I tested 13 different lamps with Aliexpress, links to which are sent readers and visitors Lamptest site (ammo1.livejournal.com/881087.html). Alas, none of the lamps that people felt good, I could not give such. The only light that had not been pulsation and CRI (Ra) more than 80, had a capacity of less than one-fifth of the promised.
I recently wrote Sergei Zeldin, who reported that he had found Ali good light bulb with a G9 socket. Sold directly in the product name is written "without pulsation (no flicker)", said color rendering index CRI (Ra)> 80 (elsewhere it is written > 85) indicates the luminous flux of 690 lm (elsewhere it is written 600-700 lm) and argues that the lamp replace halogen lamp 70 Tues.
I bought it and tested with the help of precise laboratory instruments.
Luminous flux, color temperature and color rendering index are measured using and a two-meter integrating sphere spectrometer Instrument Systems CAS 140 CT, GW Instek GPM-power consumption device 8212, device ripple Uprtek MK350D. The minimum operating voltage is measured with an instrument Lamptest-1, stabilizer Calm Instab 500 and Latro Suntek TDGC2-0.5. Before the measurements to stabilize the lamp parameter was heated for half an hour.
The result of my measurements:
Pulsation of the lamp does not, the color rendering index CRI (Ra) of about 81. This is good - this lamp can be used in residential areas, and its light is safe for eyes.
With power and luminous flux of the seller lied to by almost a third. The actual lamp power 4.7 watts (W promised 6), the luminous flux 502 lm (lumens 690 have promised). 70-watt halogen lamp, she certainly does not replace, but the 50-watt full.
The lamp may be used with circuit breakers having a display (not illuminated and does not flash when the switch is off).
Lamp driver line - the brightness varies depending on the mains voltage. Relative to the nominal luminance on voltage of 230 brightness drops by 5% with a decrease in the supply voltage up to 203 V.
At the end of the lamp has four LEDs.
With these LEDs, the lamp shines a little forward, though the basic light distribution and you have to hand.
If you know in advance that this lamp provides 500 lumens (as you now know), it can be considered good, as the light in her quality.
lamp stands $ 2.27 (about 150 rubles). with free shipping. At any warranty not count, so it remains only to hope that it will last long.
It is important to understand that in such cases produced numerous lamps G9 and not all of them good. As an example, the bulb The era of LED JCD-9W-CER-827-G9 a ripple of 100% and CRI (Ra) 73.8, which is definitely not worth buying.
After testing the bad light bulbs (ammo1.livejournal.com/881087.html), A good tape with a high CRI (ammo1.livejournal.com/917847.html) And this lamp can I conclude that on Aliexpress can buy only those light sources, which are clearly in the description stated that they no pulsation (No Flicker), shows the CRI value (Ra) of not less than 80 and the specified luminous flux in lumens (Lm, lm). All other lamps (including those from the same seller) is not worth buying.
P.S. This lamp Lamptest website: lamptest.ru/review/02349-foroureyes-g9-2835-88led-no-flicker-cri80.
© 2018 Alex Nadozhin
P.S. This article I wrote for the Habr and it was first published there.