I've got a couple LEDs that I know very little about. I'm hoping they look familiar to someone.

The smaller one on the left lights up if I supply 12V thru a 220Ω resistor. Vf = 8V. I suspect it can get a lot brighter but I have no idea of the max current rating.

The big one was in a bag labelled "150W 6000-6500K". I have no idea how to light that one up.

 

Hello,

The small one looks like this one fom Ali:
https://www.aliexpress.com/item/329...99#176_4452#5108#23442#125_4452#3564#16062#49
The big one looks a bit like this one from Ali:
https://www.aliexpress.com/i/32798666062.html

bertus

 

The small one looks like this one fom Ali:
https://www.aliexpress.com/item/32980694428.html?spm=a2g0o.detail.1000014.13.2a4f3b88KWUnZd&gps-id=pcDetailBottomMoreOtherSeller&scm=1007.33416.213724.0&scm_id=1007.33416.213724.0&scm-url=1007.33416.213724.0&pvid=1f532796-ad77-4156-8a19-fa1f301ecee8&_t=gps-idcDetailBottomMoreOtherSeller,scm-url:1007.33416.213724.0,pvid:1f532796-ad77-4156-8a19-fa1f301ecee8,tpp_buckets:668#0#131923#28_668#888#3325#16_23416#0#213724#0_23416#4721#21967#793_23416#4722#21972#6_668#2846#8109#1935_668#2717#7565#775_668#1000022185#1000066058#0_668#3422#15392#715_4452#0#214000#0_4452#3474#15675#281_4452#4862#24463#124_4452#3098#9599#176_4452#5108#23442#125_4452#3564#16062#49

Yes, although the Vf doesn't match up. A lot of the other 10W COB pieces are rated to 900mA, so I think that's a decent assumption for the one I have. I'll try 0.5A and see what happens.

I think the big one you linked may be spot-on. I'll need to up the voltage somehow to get >30V. Not sure how I'm going to do that. I suppose I could put one in series with a 60W bulb and use rectified mains.

 

NO!!! Do NOT use rectified mains power. The voltage will be excessive . Until you know the proper forward voltage there is a chance of doing damage, and with am LED device like that it is a fair amount of money's worth. There is also the problem that LEDs can easily fail from excess reverse voltage, which might even be less thatn the normal forward voltage. I followed the one link and looked at that chart and that gives a forward voltage of 30 to 34 volts. and a current of several amps. Now that the smaller one lights, you can see which side gets the positive, and there may be a similar physical clue on the larger one. Then you can experiment with applying a lower voltage to seewhat makes it light.
Another caution is that with that much power input it will get very hot very fast and so you do need a serious heat sink.

 

The smaller one is the 10 watt version.

The larger one looks like 100 watts, probably around 32 to 34 volts vf.

10 x 10 rows...150 watts is 10 x 15 rows

Although the bigger one could be 150 watts.

 

You could always put a bunch of batterys like 9V (Qty 4) in series to test it out.

 

As @MisterBill2 writes, whether it is a 10W or 150W type LED, a large/huge heat sink is needed.

 

Only if you feed it a lot of current, 20ma is always a good test current.