I found a great new LED lamp that can be transformed into an eternal lamp in five minutes.
The result is a lamp that gives 816 lumens, with a record efficiency of almost 150 lm / W and an almost unlimited lifespan.
The main reason for the failure of LED lamps is the constant overheating of components. Due to high temperatures, LEDs burn out, capacitors dry out and deteriorate. Honest manufacturers select LED modes so that they correspond to the passport ones, not very honest ones add 20 percent. Radiators in modern lamps are very small, LEDs are poorly cooled, so in the first case the lamps work on average 10 thousand hours, in the second they can burn out after 500 hours.
If you make the LEDs work not at 100 or 120% of their capabilities, but at 50-70%, the temperature on them will decrease significantly and they will become practically eternal. At the same time, the service life of the rest of the lamp components will be significantly extended, because the temperature inside the case will be much lower. Of course, the brightness of the lamp will decrease at the same time, but if you take a powerful lamp for alteration, the brightness after the modification will in many cases be sufficient.
This is exactly what we are going to do.
We'll need a lamp Lexman 12 W 1521 lumens from Leroy Merlin. Today such a lamp with warm light 2700K costs 190 rubles, with neutral light 4000K it costs 95 rubles.
According to my measurement results, a lamp with warm light consumes 11.5 W, gives 1536 lm, has a color temperature of 2692K, CRI (Ra) 82.4, there is no ripple at all. The lamp is built on an IC driver (has a built-in stabilizer) and operates without loss of brightness at a voltage of 170-250 V. The lamp has a record efficiency of 134 lumens per watt. Here is the lamp at Lamptest: https://lamptest.ru/review/03839-lexman-a60-312w27e27r/
The lamp housing is standard A60 and it gets quite hot: the temperature of the housing is 69 ° C, the thermal imager shows 83 ° C on the LEDs.
After the alteration, the lamp power decreased to 5.5 W, the luminous flux became 816 lumens. The efficiency has increased to 148.4 lm / W. Color parameters (color temperature and color rendering indices) have not changed. This light bulb will replace the 75-watt incandescent light bulb in terms of brightness.
The case temperature is 46 ° C (23 degrees lower), the temperature on the LEDs is 62 ° C (21 degrees lower). All temperatures and other parameters were measured after a half-hour warm-up.
With such heating, the LEDs will work for a very long time, I hope the other components will not fail.
In order to modify the light bulb, you need to remove the plastic cap from it. I had to tinker with this lamp - first I stuck a clerical knife into the gap between the cap and the body and "went through" two turns, then carefully inserted the tool for opening the cases into the slot and passed turnover.
There are 36 LEDs on the lamp board. On the right, above the driver microcircuit, there are two 4.7 Ohm current setting resistors (designation 4R70).
These resistors are connected in parallel. To modify the lamp, we need to remove one of them. You can remove the resistor, but it is much easier and faster to gently break it off with a flat screwdriver. It will turn out like this.
We snap the cap (you do not need to glue it, it holds on so well) and the eternal light bulb is ready.
The light bulb I have modified has a release date of 10/2020. For lamps from other batches, the board and resistor values may differ.
I carefully select the models of lamps for modification, because not all LED lamps are suitable for modification. In order to make the conversion easy, the lamp needs to have a single round PCB on which both the LEDs and all the electronic components are located. (many lamps are two-board, in order to remake such a lamp you will have to remove the board with LEDs and disconnect the leads from the base, which can be very difficult or impossible at all).
I believe that if you are going to make your lamps everlasting, it only makes sense to remodel good lamps. My criteria for a good retrofit lamp:
- impulse (IC) driver with built-in stabilizer;
- color rendering index CRI (Ra) more than 80;
- lack of ripple;
- single board design.
Lamps that are not worth trying to remodel can be distinguished by the following features:
- only LEDs are located on the top board;
- only one current-setting resistor (if the manufacturer saved on a penny resistor, believe me, everything the rest will be done with maximum economy and such a lamp, even after alteration, does not take a long time will stretch);
- color rendering index CRI (Ra) less than 80.
I will continue to look for lamps that are perfect for rework. I do not know if there are single-board "candles" and "balls" with an E14 base. It would be great to make them eternal as well.
© 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].