MicrobeHunter.com Microscopy Forum

Right so, I will leave this here just in case someone will need this info.

After a lot of trial and error, and a lack of proper electronic skills that would had probably ended this setup cheaper for me, I've managed to bring LED light into my very old zeiss.

I've used the following:

The metal plug from the old bulb, 2x radiators 20x20mm glued together with thermal conductive adhesive, 1x Nichia LED 219 series, 586lm@1800mA 5000K PCB (Star), glued with the same adhesive, 1x Mean Well Driver LCM-60 with adaptive voltage 2-90V at 500-1500mA.

I've reached this setup because cheap high powered LED lights get very hot, and a proper driver was needed to reduce the possibility of strobe light effect or overheating issues. The LED is CRI85 I think.

Obviously, the build is not perfect in therms of temperature dissipation, because that adhesive is quite low cost, but it does the job . And I will also need a dimmer. The LED runs at 2.7 volts (the driver adapts itself to the typical voltage of the LED and I've burned a few LED until I realized that) and at 900mA, I did not notice any overheating at 900mA, and the light is way too strong.

Now another problem is chromatic aberration when using a mirrorless camera with my scope, but hopefully I will sort it out or reduce it with a hybrid ocular.

https://imgur.com/a/9tQrAXq

https://imgur.com/a/S0x6PEm

Cool! As you bring this development to the final, be sure to share

alexgor26 wrote: ↑

Thu Jul 28, 2022 9:05 pm

Cool! As you bring this development to the final, be sure to share

Thanks.

Yes I will. My biggest fear is that the ocular hybrid setup that I will try to mount with my mirrorless camera, wont change much the chromatic ab. This will force me to use a phone through the ocular, and not a professional camera. Still better than nothing I presume.

Nice, I managed to use around 10W without overheating inside the base, don't remember exactly. I feel I could squeeze a bit more.

I learned a few days ago that the thermal adhesive bonds very tight after a few months of use. I spent almost half an hour removing the led from the heatsink, with a Dremel. The led I use is made of some pretty solid material.
So now I put 2 screws to hold the led and used thermal paste (typical CPU type), next time it will be a lot easier to swap the LED.

Cristian11 wrote: ↑

Thu Jul 28, 2022 9:55 pm

My biggest fear is that the ocular hybrid setup that I will try to mount with my mirrorless camera, wont change much the chromatic ab.

I'll try the hybrid next week too kpl 10 is in the mail. I think it should reduce the CA, probably not remove it completely at least not with all of my objectives, but still hoping to have much less. We'll see...

imkap wrote: ↑

Thu Jul 28, 2022 10:15 pm

Nice, I managed to use around 10W without overheating inside the base, don't remember exactly. I feel I could squeeze a bit more.

I learned a few days ago that the thermal adhesive bonds very tight after a few months of use. I spent almost half an hour removing the led from the heatsink, with a Dremel. The led I use is made of some pretty solid material.
So now I put 2 screws to hold the led and used thermal paste (typical CPU type), next time it will be a lot easier to swap the LED.

Question, why did you used a COB Led and not a diod LED ? I know a COB consists basically of multiple small LED diodes, therefore the light projected is not uniform from a single point.

I'm curious if there is any difference at all when it comes to COB vs Diode

I didn't want a 3V as it would need 4A for 12W, so didn't have a psu or a converter for that. So found the 18V 700m COB. I didn't notice the field isn't uniform, don't have the 1 diode led to compare.