Controlling a (single) 10A LED

Using Arduino Motors, Mechanics, Power and CNC
1

I want to control a single LED (Osram LE CG P2AQ) with an Arduino (simple on/off). What is the best way of achieving this?

Simply connecting a 10A current supply via a Mosfet?

Using a Buck Converter module that can handle 10A and use the PWM just for on/off?

It has to be very fast (as in milliseconds), thus a relay is out of the question.

Thanks for any pointers or concrete advice :slight_smile:

Edit: I mixed up my unites. msec, not µsec.

2

Please post a link to the datasheet.

Please explain why. What's your project about?

3

MOSFET seems to be the best solution. No need for PWM if you just want on/off control.

This:

Can be interpreted 2 way, either or both could be relevant.

  • You could mean that the time from some event that triggers turning the LED on or off must not be more then 1μs
  • You could mean that the rise and fall time, as in the time it takes to apply or remove the power, cannot be more than 1μs

Those are different requirements, which one applies?

Knowing what you are really trying to do would get you better answers.

4

The LED is rated 1kHz. At a higher freqency or pulse rate you have to provide a sufficiently fast 10A pulse source and eventually face possible unexpected LED behaviour.

5

Thanks. The datasheet is here. In the project I use several LEDs with a monochromatic camera to get a multispectral image of a film. Since I also have to use a filter, I ran some tests with a power supply and figured out that I need to run the LED at 10A.

6

Dear Perry,
Thank you for taking the time to reply :slight_smile:
It is the former requirement; the LED needs to be turned on, stay on for a (controllable) amount of milliseconds and then be turned off again.

7

Thanks, Diettrich. I was not clear enough. The LED will not be pulsed, it just needs to be turned on for (a controllable amount of ) milliseconds. It will, and should not, be pulsed.

8

I am willing to bet your Buck converter cannot respond to a 10A load that appears and disappears in milliseconds. You need a vary large capacitor with very low ESR. Remember the photoflash devices.
Paul

9

The LED is rated 1kHz.

I believe the LED is tested at 1kHz, 6 A forward current and a 50% duty cycle.

10

Of course nothing is simple.

Please expand your explanation of your goal. Pulsing an LED on for µS is a lot different than operating for seconds.

  • Thermal concerns
  • Transient response of the current source

If my guess is correct you wish to use these LED as sort of a color filtered flash then you are best using a simple resistor and Mosfet for on off. You will need a Mosfet driver as the Arduino cannot supply enough current at its outputs to switch a Mosfet very fast.

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