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Topic: How to vary brightness of high-powered LED with arduino (Read 2 times) previous topic - next topic

JRules

Hello all,

I'd like to use my arduino to control a high-powered blue LED with varying brightness.  I want to use a Prizmatix Mic-LED-450. (Here's the 385 version http://www.prizmatix.com/pdf/mic/Microscope-LED-385.pdf). It has a forward voltage of 24V, so obviously requires more voltage than the arduino can provide.  What's the best way to do this?  Any help is appreciated!

Grumpy_Mike

Have you got the BLCC-02 Benchtop LED Current Controller?

If so it will simply accept one of the PWM output pins from the Arduino. Don't forget to connect the ground of the LED supply to the ground of the Arduino together.

JRules

It's on order right now.  In the pdf provided, in the section for the BLCC-02 specs, it says the input voltage is 24V.  Why does it need an output from the arduino?  Won't it be powered by a wall socket?  Can I just have the a wire extend fromt the pin to a resistor to the LED to the arduino GND?

Grumpy_Mike

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Why does it need an output from the arduino?

In order to control the brightness, that is what you want isn't it?

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Can I just have the a wire extend fromt the pin to a resistor to the LED to the arduino GND?

No this is not an LED, it is a constant current supply powering the LED. There is no resistor needed.

JRules

Update: I'm neither getting the LED I mentioned earlier nor the current controller.  Turns out they're really expensive: $1050 and $750 respectively, though I'm not sure what I was expecting.  I'll have to find some other bulb.  I guess my question is the same, but without the current controller.  Grumpy_Mike, thank you so much for helping.

Chagrin

The part you're really paying for is their collimator/optics. A constant current LED driver capable of the maximum 24W supplied by their power supply is easily under $10. The LEDs, heatsink, etc. would all be well under $50. 

Headroom

No! What you're paying for is a fully developed integrated system that is aimed at a very specific low-volume market. It likely comes well packaged with documentation, and is probably backed by a support and business infrastructure. THAT is what you are paying for! Reducing this to pure hardware cost only is a bit naive.

@OP
http://www.ledengin.com/products/emitters#LZ4 LedEngin makes some High Power specialty LEDs two versions of UV LEDs are amongst them. Then you need a power supply and a constant current LED driver.
This one http://ledsee.com/index.php/new-products/arduino-6-channel-led-shield-035-07-1a-detail for example should work and plugs right on top of an Arduino.
http://trippylighting.com

http://ledshield.wordpress.com/

JRules

Ok I think I'll use this bulb (http://www.luxeonstar.com/Blue-470nm-Star-O-Replacement-70-lm-p/sr-12-b0040.htm) with this constant current driver (http://www.luxdrive.com/content/3021-BuckPuck.pdf) and use the arduino's 5V to control the current through the driver.  And I guess I'll need a power converter from a wall outlet to the current driver.  Would that work?

Grumpy_Mike

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Would that work?

Yes but you have to look at mounting that LED on a suitable heat sink.

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