144 LED chinese ring light

[u666sa]

I ordered this 144 chinese LED ring light for my microscope, and the light wasn't any good.  In comparison to my 56 LED stock ring light it was same brightness, minus lower color temperature which made it even less bright. I modified it. Gave it 12V 2.7 amps, the thing melted a little bit. I mean, maximum it takes 1.25 amps and at that power it melted after about 20 minutes of work. Stock it is limited to 225 milliamps.

I modified it then a bit differently, gave it 18 volts and made a current regulator, limiting current to 650 milliamps. Now it is bright and does not melt. It is great at minimal to medium zoom, but when I use 0.5 barlow and do max zoom the picture is kinda dark.

It has 3 mm pointed LEDs. I was thinking of installing 5 mm pointed LEDs instead. There is also option for 5 mm straw hat none pointed LEDs. They all will fit nicely. Which would be a better option in your opinion? Pointed or none pointed?

Pointed light


None pointed light

[liaifat85]

As you are gonna use it in your microscope, I think pointed is better.

[jfiresto]

I also think you will be happier with LEDs with a more narrow beam that will throw a greater fraction of light on the object you are viewing. Have you measured the geometry of the illumination cone from the present ring light and is it good for your working distances from light to object?

If I were going to go to the trouble of swapping all those LEDs, I would use first run parts that have a datasheet and have been binned for a brightness and color.

[u666sa]

Have you measured the geometry of the illumination cone from the present ring light and is it good for your working distances from light to object?

This light is absolute crap.
The 56 LED that came with microscope has a nice cone. This one, even in its stock form, had no cone, even tho LEDs were angled.
The only thing that makes it worth while is a) it already melted. and b) if you give it a lot of power cone doesn't seem to matter much.

If I were going to go to the trouble of swapping all those LEDs, I would use first run parts that have a datasheet and have been binned for a brightness and color.

Could you find me something like that on aliexpress?

[coromonadalix]

seriously   a simple search like this on ALi :  microscope led ring      give tons of results ??

[jfiresto]

If I were going to go to the trouble of swapping all those LEDs, I would use first run parts that have a datasheet and have been binned for a brightness and color.

Could you find me something like that on aliexpress?

Now that I think of it, so far nothing I have looked at on aliexpress has had enough of a datasheet to design from. I suspect a firm datasheet might make it hard to sell things that are "good enough".

[u666sa]

I ended up buying these -- https://aliexpress.ru/item/1005003668136913.html
100 pc cost me $1.49

Now here is where fun begins. Supposedly so many LEDs considered wholesale party! 
I'm waiting to see what happens on customs. Supposedly we are allowed €1000 per package, so long as item is for personal use and is not wholesale, meaning so long as you not ordering more than certain amount of same thing. I'm hoping on adequacy at the border. If it goes through I'll order another 100 pc.