I installed 20 of those. A week later, one of them was dimmed and flickering/flashing. Two months later I had the problem with half of them. So before buying some more, I started investigating what might be going on.
I found out that the internal PSU of the bulbs was ok, so I checked the led’s inside the bulbs one-by-one using a 12V transformer and a 180Ohms resistor in series. The conclusion was that one of three led’s inside each bulb was “blown”. Because they are soldered in series, all 3 of them were flickering/flashing. So I swapped some of the healthy ones replacing the blown ones and voila! They were ok.
Although I was happy of my findings, I am not happy with the greenish “warm-white” chinese light. So I started searching for replacement leds.
The PSU inside the bulb is tiny and although I would like to experiment, I wouldn’t like to burn the PSUs. So I have to be careful of the wattage of the leds I’m going to use.
The guy offering the bulbs suggests that they are 9W. 3W per led?? I doubt that…
Could you please identify the leds and if possible the wattage? Are they any good - what do you think of them?
Could you suggest any brand/type for replacement?
Thank you for your time!!
I will post photos with the results!
Those are most likely no-name Chinese craptastic LEDs made by Hu Yo Mama Lighting and Cat Food Concern #23. The fine print in the listing says that it is actually a 4 watt bulb. My bet is 3 watts and maybe 150 lumens.
I have noticed that some of these that I have do not have any thermal grease under the star. Also these lights rely on pressure from the cover screwed in to the sink pressing down on the lenses for physical contact between the star and the heat sink. Bad design. The star should be screwed or glued to the sink.
Here are what I believe could be replacement LED’s.
If the whole bulb equals 4 watts, then how many watts should each led equal to? 1.33 ?? Hehe chinese mystery!
You are right dchomak. The whole construction is exactly how you described it. I will need lot of thermal paste for that. If the screws are tight, the pressure should be adequate.
I am searching for leds to replace on the existing pcb. And it needs 3 of them because of the topology of the lenses. Or maybe not?? I don’t know… What do you suggest? Which leds are best? 3 leds of 1 watt each, 3 leds of 2W, or 1 led of 3-5w? And which ones?
Yeah, those are the typical cheap egg-yolk emitters. I have a few of those budget LED bulbs and have had several with the same issue. I bought a big bag of spare emitters from ebay for a couple of bucks and swap them as needed. I just use two series-connected AA cells and use alligator leads to touch the connectors on each emitter until I find the one that's not working. Like dchomak mentioned above, the heat sinking on these are pretty poor so I Fujik the new emitters onto the board...
<edited to add...>@ $1-1.39 each from fasttech, I would take the gamble on the DX emitters first... I'm not a DX fan and have had some issues getting stuff from them, but they have been quicker to address my issues lately...
Cool project! I noticed that my budget led lights fit the same way, but haven't ever actually put it together. The cool white would be nice for that project. I'm thinking about getting one of the 3w cool white to make a P60 drop-in and add an aspheric lens... See what kind of beam profile I can get with the round emitter die/phosphor/?...
