I found this led desklamp on the streets, opposite the Wertheimpark in Amsterdam, and it looked like a quality lamp, heavy and quality materials, possibly an expensive design lamp. So I brought it home, and although it was not from a famous design brand after all, it was a danisch lamp and it looks exceptionally well-built. On the internet it is mostly sold-out but it is still on sale in some shops and sells for 100 euro.
I thought it was nice to start a thread about it because I want to keep it, but it desperately needs modding because I measured the leds at (2900K and) a whopping 46 CRI ! . I assume that the lamp is from before 2010 when even 70 CRI was considered a high quality tint.
The tint is not as yellow as in the picture, it looks even good, until you try to illuminate something with red-tints in it :confounded:
I will update, with pics, about the teardown and hopefully a succesful led-upgrade, depending on what appears the footprint, MCPCB- type etc.
This is the business end, it looks like three separate TIR’s, and the leds look like mounted on a big ribbed heatsink and there is a free airflow through the lamp head for cooling it
The power supply is a basic 12V 700mA plug-type thing, no pics but the inside looks well-done, with a good spacing between the high-voltage and low-voltage side (no pics of that). I found it with the housing open so I did a quick repair with a tie-rap.
The switch is a mechanical rotary switch with a simple dimming system, off-1led-2led-3led. The knob seems shiny-coated plastic, so not really high-end IMO, but luckily in as-new condition
High CRI did exist before 2010, I found a data sheet for an old warm white SSC P4 LED (I installed one in a tent light) and was surprised to see the CRI listed as 95.
I see, thanks for correcting me . I am into led flashlights since 2011 and the 90CRI Nichia 219A was exciting and new at the time, so I assumed that high CRI was sort of non-existent before then.
At least for this lamp they did not bother to use a decent CRI. When I open it I will try to figure out what leds it is.
Here’s the teardown.
And as was to be expected, those oldschool type of leds with lips to handsolder them in.
So what is the way to go from here? Adapting this for 3535 leds is one way, because these “bead” leds are very high-up, I could replace them with LH351D leds reflowed on 10mm boards, glued on the stock PCB (heatsinking should be ok-ish at <500mA per led).
Or I could scour aliexpress for a modern high CRI version of this led-type, I am still seeing these around.
The height does not match, and the 10mm board does not fit between the solder pads on the big PCB, but it can be made to work with some effort.
In the meantime I also looked over aliexpress and did not quite find what I wanted but maybe close enough: the highest (claimed) CRI was 85 for this led type (in 3000K). But since it was €2.85 shipped for 20 leds I ordered them, let’s see what I get.
Looks like a nice lamp. I think the traditional method of adaptation would be to add a copper spacer under the MCPCB, cut from a copper rod of appropriate size.
But if the aliexpress LEDs work, that’s easier and cheaper! See this thread in a month or so.
. I assume that the lamp is from before 2010 when even 70 CRI was considered a high quality tint.
. I am into led flashlights since 2011 and the 90CRI Nichia 219A was exciting and new at the time, so I assumed that high CRI was sort of non-existent before then.
