LED driver for high power LED's

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I have a project I'm thinking about doing with 6 bridgelux LED's at 350mA they provide 1220 Lm. They have a 27.2 VF rating anyways I'm wondering what driver rating do I need to drive 6 of them in series?

I assume as long as the driver puts out 27V @ 300mA I can drive all 6 in series? It's kind of hard to find a 27V driver.. and I noticed on ebay they have cheap drivers but with a wipe output voltage which I don't know if it's adjustable.
 
Please post a link to the ebay drivers you are looking at.
Some of the drivers top out before 27 volts.
You could run them as 600mA @ 19 volts by making two strings of three.

If you look at the data sheet very carefully (ebay LEDs don't have data sheets), the 27.2V is 'typical' and could be +20% or -30%. It is the 300mA you want.
 

This is the datasheet I'm looking at

https://www.electro-tech-online.com/custompdfs/2013/08/Vero201020Datasheet2004-16-13.pdf

At 350mA the min voltage is 25V and the max is 29.4V

The drivers with wide ranges are something like these and yes I know these are AC input.

**broken link removed**

**broken link removed**
 
There is no 'adjustment' for voltage. When using LEDs you do not set a voltage. You set the current.
So model 8-12xW outputs 300mA +/-5%. You can use any combination of LEDs that add up to 24 volts to 42 volts. The driver's job is to push the voltage up until 300mA is reached. (as long as it is in 24-42 range) The voltage will be different with temperature. It will be different with every batch of LEDs you get. That does not matter.

It is hard to explain that light bulbs are voltage devices. 12V makes light.
LEDs are current devices. 300mA makes light and the voltage is not so important.
Your diodes could be from 25.0 to 29.4 volts at 350mA. The voltage will be very slightly lower at 300mA.

1 watt LEDs need a heat sink!
 

Ah right one of the reasons you don't use resistors with high powered LED's makes sense, I know about the heatsink I just don't know how thick of a metal plate I need and if I should have active cooling with it since the fixture is going to be outside and with a cover over it.
 
Heat sink is hard to figure out.
With plastic flashlights we had to reduce the power. With aluminum flashlights we pushed the heat into the body of the enclosure and run the LEDs at full power.
Some flashlights measure the LEDs temperature and adjust the current. Some drive with 2x or 1.5x current until the temperature reaches the limit. (20 to 30 seconds). This way we can have a very large Lm number.
LED life and temperature are very related.

Can you get the heat to the outside of the enclosure?
 
Not really.. on the back is a fiberglass covering which that part will be on the house, I've thought about a TEC but the return is not good I've thought about a fan but not 100% sure on it.. The fan would be sucking in air between the vinyl siding and the house and blowing into the housing.
 
You can use resistors with high power leds, the function would be the same as a panel indicator, its just that at higher power levels its well inefficient, supplying a constant current from a circuit, particularly a switcher is more efficient and you can run the led at its max constantly.
Heatsinking is important not only to protect the led but also a led operating at a higher temp will not produce the same amount of light as one running cooler at the same current, I found this out recently.
 
You can probably run three in series using the 87 volt one. It doesn't worst case but I don't think it gets to -40 C even in Connecticut.

To be totally safe you could run two in series with the 65 volt one.

So at 300 ma each one dissipates about 7.5 watts. 1.5 c/watt from the junction to the case so to keep the temperature below 75C (pretty hot) would take about 100 sq. cms.

I think I would buy one like this to have some margin in the summer.

**broken link removed**
 


The issue with those heatsinks are they are almost all the same shape and bulky.. If you haven't seen how the fixture looks with a cover you can see it now.. it would be impossible with those heatsinks.

**broken link removed**
**broken link removed**
 
So I'm guessing your taking a bulb out of that and putting 1 LED into it?
Maybe 5 fins worth of something like this would do it. Looks like it might fit.

**broken link removed**

I'm not sure how well this will work inside the insulated enclosure. What wattage is the bulb that is in it?
 
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The wattage was a 7W CFL, and I'm putting 6 LED's in it would run cooler then trying to run a single LED at like 4A 37V

Your link is not for AC line voltage.
 
The link is right now, but it would be for a single LED. I don't think you will get 6 of them in there. That would be about 45 watts. Do you really need that many. A single one should be about the same brightness as a 60 watt light bulb.
 
Then you need a bigger fixture or perhaps replace the back plate with a heatsink if you have room. The sodium lamp runs at a much higher temperature than the LEDs can.
 
7 10w leds wouldnt give you much more brightness than a son, or more efficiency but you would have white light.
 
dr pepper said:
7 10w leds wouldnt give you much more brightness than a son, or more efficiency but you would have white light.
Click to expand...


I was not really expecting more efficiency but it will be a little brighter.. I plan on doing another on the side of the house because of an issue with raccoons, being as the HPS is orange it makes it a little hard to see.
 
Most led based outdoor lights use passive cooling ... the fixtures' outer shell is metal and it has fins on it to increase surface area. Having a fan in there is just too unreliable.
 
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