Traffic light stores sell very cheap LED bulbs - 34 rubles 60 kopecks apiece. I bought one in March and the second in June. It turned out that they are radically different.
A lot of good things are indicated on the lamp box: power 15 W, luminous flux 1425 lm, analogue of a lamp incandescent 120 W, color rendering index 80+, ripple coefficient <5%, allowable voltage 230V ± 10% (207-253 V).
Unfortunately, in the new lamps, all this is not true.
The lamp purchased in March (code EL0512007, release date 07.2020) had a measured power of 7.7 W, luminous flux of 699 lm (equivalent to 70 W), but the LEDs were good there (CRI 81) and at a mains voltage of 230V there was no ripple It was. Despite the linear driver, the lamp more or less withstood the specified voltage range: at 207V, the brightness dropped by 7%, the ripple did not exceed 15%. Here are the results of measurements of this lamp on Lamptest: https://lamptest.ru/review/03775-ergolux-led-a60p-15w-e27-4k-promo.
The lamp purchased in June (code 3L1162012, release date 12.2020), when turned on, surprised with one hundred percent ripple, clearly visible visually.
I removed the caps from the old and new lamp, and everything immediately became clear: the new lamp simply does not have a smoothing capacitor: saved on the health of customers (the pulsation of light can lead to eye fatigue, headaches and aggravation of nervous diseases).
The boards of the lamps are different, and the LEDs in the new one are different, of a smaller size.
I measured the light parameters of old and new lamps with the Uprtek MK350D spectrometer. The new lamp has a low CRI (Ra) 72 measured color rendering index and a 100% ripple factor.
The measured power consumption of the new lamp turned out to be 6.3 W, and the luminous flux was only 494 lm (equivalent to a 50 W incandescent lamp). The power was measured with a Robiton PM-2 instrument, the luminous flux in an integrating sphere of 50 cm using the same Uprtek MK350D spectrometer.
When the mains voltage drops to 225V, the lamp brightness drops by 5%, at 221V by 10%, at 213V by 20%, at 207V (lower level range specified by the manufacturer) the brightness of the lamp drops by 30%, at 202V by 40%, at 197V by 50%, at 190V by 60%, at 183V by 70%.
This means that when used in a real network with a voltage of 210-220 V, the lamp will shine like a 40-watt incandescent lamp.
Unlike the old version, the lamp does not work correctly with switches that have an indicator: it glows dimly when the switch is off.
Compare the manufacturer's promises and the measurement results:
Promised ripple <5%, measured 100%;
Promised 15 W, measured 6.3 W;
They promised to replace a 120 W incandescent lamp, measured 40-50 W, depending on the voltage in the network;
Promised 1425 lm, measured 346-494 lm (at a voltage of 207-230V);
They promised a color rendering index of 80+, measured 72.
Here is such a "modernization" - a light bulb with good LEDs, no ripple, but with half the power and brightness that could still be used turned into a light bulb, worse than which I have not been lately met.
© 2021, Alexey Nadezhin
For ten years I have been writing every day about technology, discounts, places of interest and events. Read my blog on the site ammo1.ru, in LJ, Zen, Mirtesen, Telegram.
My projects:
Lamptest.ru. I test LED lamps and help figure out which ones are good and which are not so good.
Elerus.ru. I collect information about domestic electronic devices for personal use and share it.
You can contact me in Telegram @ ammo1 and by mail [email protected].