Meanwell LDD drivers

[fatman]

Does anyone know if these LDD drivers offer deep diming or basically being able to dim the light output to zero. Instead of the 50 to 100% that the ELN drivers seem to do.

I haven't tried them, but I have been told by people that do use them that they will go right down to zero so you can dim below the usual 10% cutoff. I should have about 6 channels up this fall using them.

Fat

[cjrudy]

Does anyone know if these LDD drivers offer deep diming or basically being able to dim the light output to zero. Instead of the 50 to 100% that the ELN drivers seem to do.

I haven't tried them, but I have been told by people that do use them that they will go right down to zero so you can dim below the usual 10% cutoff. I should have about 6 channels up this fall using them.

Fat

+1

They go right to zero, the advantage of that is freeing up a at least two ports on my relay box.

[thekameleon]

You say down to zero, so that applies to output as well. With my Meanwell drivers, when I apply 10% the LEDs seem to be at 50% brightness already. So with the LDD at 10% at the input will I have 10% brightness?

[rimai]

That's the human eye perception to light...
You can correct it through math.
http://neuroelec.com/2011/04/led-bright ... ection-no/

[rimai]

Talk to Kraven.
http://forum.reefangel.com/viewtopic.php?p=25582#p25582

[Rodasphoto]

I have ldd drivers on a DIY build I just completed and they do dim to 0. I currently use my near uv and royal blue set around 3 or so as moon lights.

[KRavEN]

Talk to Kraven.
http://forum.reefangel.com/viewtopic.php?p=25582#p25582

Here's code that take 0 to 100 percent and converts to 12bit PWM corrected luminance value. If you're using 8 bit change PwmMax to 255.

Code: Select all

int RA_PWM::getLuminanceValue(byte Percentage) {
  int PwmMax = 4095, Steps = 100;
  int value;
  float Lum, Pwm;
  Lum = ((float) Percentage / (Steps - 1)) * 100.0;

  if (Lum < 8.0) {
    Pwm = Lum / 903.3;
  }
  else {
    Pwm = pow(((Lum + 16) / 116), 3);
  }

  value = (int) round (Pwm * PwmMax);
  return value;
}

[KRavEN]

Talk to Kraven.
http://forum.reefangel.com/viewtopic.php?p=25582#p25582

Here's code that take 0 to 100 percent and converts to 12bit PWM corrected luminance value. If you're using 8 bit change PwmMax to 255.

Code: Select all

int RA_PWM::getLuminanceValue(byte Percentage) {
  int PwmMax = 4095, Steps = 100;
  int value;
  float Lum, Pwm;
  Lum = ((float) Percentage / (Steps - 1)) * 100.0;

  if (Lum < 8.0) {
    Pwm = Lum / 903.3;
  }
  else {
    Pwm = pow(((Lum + 16) / 116), 3);
  }

  value = (int) round (Pwm * PwmMax);
  return value;
}

Actually if you're looping 0 to 100 the Steps should be 101 because 0 is a step. So for 8 bit it would be:
int PwmMax = 255, Steps = 101;

And 12bit:
int PwmMax = 4095, Steps = 101;