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I want to drive 6 "Rebel 7 LED Round Assemblies" at their 1000mA Maximum Rated Drive Current.
I want to drive 6 "Rebel 7 LED Round Assemblies" at their 1000mA Maximum Rated Drive Current. This will be a battery powered mobile lighting source. Can you suggest the proper BuckBlock DC Driver or multiple driver configurations that would accommodate 6 "Rebel 7 LED Round Assemblies?"
2 Agent Answers
To determine what you would need we would need to know which model of the 7 LED round assembly you are using as well as the input voltage that you have available. (E.g., 12VDC, 24VDC)
This article provides details on how to determine how many BuckPuck/PowerPucks you will need for your specific application:
http://support.luxeonstar.com/customer/portal/articles/182673-how-many-leds-can-i-power-using-a-buckpuck-or-powerpuck-driver-
The best option would be to use the FlexBlock driver. This driver can be operated in boost mode so that it can power as many as 9 series connected LEDs from a 12VDC power source. You will find more details about this driver here:
http://www.luxeonstar.com/700mA-Externally-Dimmable-FlexBlock-Driver-p/a011-d-v-700.htm
The National Semi driver evaluation board you are looking at would be a pretty expensive solution and will be limited to powering about 5 series connected LEDs.
As for mounting the LED assemblies on aluminum sheeting, this will almost certainly not provide enough heat dissipation to cool the LEDs. You need to mount each LED assembly onto a finned heat sink. The size of heat sink you will need will depend on your specific requirements, but as a starting point a heat sink with a C/W rating of 3.5 or lower should work. Here is a list of possible heatsinks:
http://www.luxeonstar.com/3-to-3-9-C-W-Heat-Sinks-s/215.htm
3 Community Answers
I saw the question from the guy above and was wondering the exact same thing. I would like to run from 4 to 8 of these Rebel 7 LED Round Assemblies (or whatever an optimum number might be for the power supply).
I use 12v. sealed lead batteries.
I don't have a fixture in mind but might just mount them to aluminum sheeting as a combo reflector/heat sink.
If you have a fixture in mind I would be interested.
I saw this driver advertised and wonder if you think it would work:
http://www.futureelectronics.com/en/technologies/development-tools/analog-power/Pages/4557567-LM3405AEVAL-NOPB.aspx?IM=0
If you could email me a response it would be appreciated.
I really Doubt that .In fact I think it was on one of the shows on HGTV saw smnoeoe with a huge circuit board sheet in a frame. Looked like modern art. I actually hang electronics I've pulled out of stuff on the wall around my desk
Not providing sufficient cooling for high brightness LEDs is a common mistake made by many inexperienced designers. The problem is that the LEDs will appear to be working fine, even though the junction temperature is probably much higher than it should be. LED thermal failure due to insufficient cooling happens slowly, imperceptibly. Weeks, or even months after you have built your lighting system or started shipping your products.
The speed at which the light output will degrade will depend on the actual junction temperature of the LED. The higher the temperature, the shorter the life of the LED.
For example, if you operate a typical white LED at a junction temperature of say 135 deg C, then the operating life of the LED is projected to be about 60,000 hours. However if you increase that temperature to the LEDs maximum junction rating of 150 deg C, then the operating life of the LED will drop to 15,000 hours. If you go above the maximum junction temperature rating of the LED, then the LED life will be reduced to hundreds or even tens of hours before it gradually dims to less than 70% of it's original light output. (As LEDs typically do not fail outright, they are considered at the end of their life when the light output drops below 70% of their original brightness.)
So providing adequate cooling is vital to ensuring long LED life. Based on our experience, mounting LEDs to a simple flat aluminium plate will not provide sufficient cooling. You need to mount the LED to a finned heat sink. Something with as much dissipation surface area as possible.