Driverless COB LED?

[Dimitri Stephan]

I want to convert my old incandescent photography light to an LED one but since there is no space for a drive inside the body, It would be nice to have the driver integrated into the LED package.

Only issue is I haven't been able to find one with a light emitting diameter of 25 mm and a power output of 100 W.

Do these exist or are the square ones the only ones with this option?

 

[Lynx_Arc]

I'm thinking if you don't have room to spare for a driver then you may not have enough space for proper heatsinking of an LED capable of the output you desire. I also am not sure what you mean by power output of 100W... is that akin to how light bulbs are rated (compared to original incans) that 100W would be around 1600 lumens? I also don't recommend COB lighting if space is a premium as COB aren't nearly as efficient LEDs compared to something like a CREE XHP emitter. I think COB LEDs are in the 80-100 lumens/watt while some high end crees can do 125-200 lumens/watt. One issue is when you are driving an emitter at high output efficiency can take a big hit too.

 

[Dimitri Stephan]

I'm thinking if you don't have room to spare for a driver then you may not have enough space for proper heatsinking of an LED capable of the output you desire. I also am not sure what you mean by power output of 100W... is that akin to how light bulbs are rated (compared to original incans) that 100W would be around 1600 lumens? I also don't recommend COB lighting if space is a premium as COB aren't nearly as efficient LEDs compared to something like a CREE XHP emitter. I think COB LEDs are in the 80-100 lumens/watt while some high end crees can do 125-200 lumens/watt. One issue is when you are driving an emitter at high output efficiency can take a big hit too.

There is space for a 80x50mm heatsink and fan but no space for the LED driver inside the enclosure so if I do not find a driverless one, I will need power it externally with a brick type CC driver.

I know most 100W LEDs are capable of outputting around 10000 Lumens which is what I'm trying to achieve. Do you recommend other LEDs that fit my requirements?

 

[DIWdiver]

A COB running at anywhere near 100W is going to generate around 50W of heat. That's way too much for that tiny heatsink.

 

[Lynx_Arc]

There is space for a 80x50mm heatsink and fan but no space for the LED driver inside the enclosure so if I do not find a driverless one, I will need power it externally with a brick type CC driver.

I know most 100W LEDs are capable of outputting around 10000 Lumens which is what I'm trying to achieve. Do you recommend other LEDs that fit my requirements?

I'm basically over my head in all of this as I don't have knowledge of individual LEDs of this high power output but have gleaned info regarding the technology here and there. I'm thinking you may need twice the heatsink and perhaps may even have to opt for Cree COB LED to get more efficiency which means less heat. I'm not quite up on Cree high power emitters like the XH-P series and them compared to COBs but it would probably require several of them to equal 10k lumens I would think but could possibly be more efficient.
Hopefully someone into high power lumen output like these soda can lights will chime in and lend some expertise.

 

[RetroTechie]

Cree website -> LED Components -> XLamp LEDs -> select list view -> scroll down to "Featured Integrated Arrays". There's several types that go into 10,000+ lumen range, 50..100W or above, >100 lm/W and high CRI (90+ usually) option available. Around 20..30 mm square (so apart from the ceramic substrate, actual emitter area is smaller).

No doubt some of Cree's competitors have similar products on offer. Note there exist 95+ CRI LEDs from other vendors (often targeted at photography applications). But above 90 CRI chances are for a modest improvement in color spectrum you'll pay a heavy price in the lumens/W department. And thus, also more heat to get rid of for same light output.

@DIWdiver:

.. and fan ..

Forced airflow makes a looott of difference... Or you could take a variable current driver, and dial up the CoB LED's output to whatever the cooling can handle.

External driver will be the way to go for sure. That's the whole point of CoB LEDs: separate driver & LED so that there's always some combination you can find to suit a particular application (and don't have to toss a $30+ LED because a $0.10 capacitor in a $5 driver failed :laughing: ).