DIY LEDs - The write-up

[saf1]

Not sure who you're referring to, but I got my LEDs from rapid led. I did get the meanwell drivers as part of a larger kit. By turnaround do you mean shipping time? It was pretty quick, I don't remember exactly but I'd say I received the goods in about 2 days. No fancy packaging or anything but everything I ordered was in the box and it came pretty quickly.

Yep - you got it, and thanks. I'm going to order some stuff and they have a pretty reasonable price across the board it seems. So thanks.

I'm going to be taking down my 100 gallon main display since it is sort of on auto pilot since my vacation crash. Live rock recovered nicely as did the sand. Orange buttom polyps are all over the place probably due to water quality but never the less it needs to be down for a while until I can frontload it a bit with time and energy.

So I'm going to use a 6 gallon eclipse tank I have boxed up, fill it with some sand and rock from my display. Capture the 2 clowns, royal gramma, snails, and put them in there. Looking at the hood it comes with it will be a easy gutting of the light it has in the hood then retro LED's into it for a nice desktop set up.

6 gallon nano sounds about my speed at the moment. I'm thinking 1 meanwell with 8 leds 4 royal blue and 4 of the whites should be more than enough for 6 gallons. Maybe even do 6 around the outside parameter with 1 blue 1 white using optics for center.

 

[der_wille_zur_macht]

PowermanKW,

I have built a variable speed fan controller before using the PWM function on a microcontroller.

I believe the arduino has PWM built in. Is it 5 VDC output logic levels?
If so, you can directly control a N-type FET an "dim" the fans.

BTW - what part of Colorado are you in?

Stu

I've done this on an arduino, and while it works, it tends to produce some "growl" as you turn the speed down due to the on/off nature of PWM. I've heard you can fix this via an resistor-capacitor filter on the output side of the FET but I didn't try that.

 

[Santoki]

Are there any disadvantages to wiring the fan into the LED array?
The way I figure, the fan need not spin fast at all, as long as some air is being moved over the heatsink, significant cooling can be achieved.

 

[der_wille_zur_macht]

You CANNOT wire it into the LED array, meaning on the same circuit as the LEDs themselves ("downstream" of the driver).

You CAN wire it to the DC power supply that is supplying the LED driver with power. That's fine.

Perhaps some of the confusion here is due to the fact that some drivers are "all in one" i.e. they combine an DC power supply and a constant current driver in the same package (the meanwell drivers are like this.) Versus some other drivers, like the buckpucks, which have a separate DC power supply. If you are using meanwell-style drivers, you can't wire the fan to the driver. If you are using buckpuck-style drivers, with a separate DC supply, you can definitely wire fans (or anything else, within limits) to the DC supply - just make sure the voltage and current draw is appropriate.

 

[Santoki]

Yes, that is exactly where the confusion is.. at least for me.
thanks for clarifying...

 

[james3370]

Yes, that is exactly where the confusion is.. at least for me.
thanks for clarifying...

yeah, to maybe clarify what DWZM said to those that might not still understand......

dc power supply(+) ---> (+)of fan & (+)input side of buckpuck(s) tied together

dc power supply(-) ---> (-) of fan & (-)input side of buckpuck(s) tied together

 

[der_wille_zur_macht]

Assuming the DC supply is at the right voltage that'll work fine. Many people are using 24v supplies for buckpuck-driven LEDs, and 99% of PC-style cooling fans are 12v. So you'd have to knock the voltage down, or wire them in series pairs such that each fan saw 12v.

 

[james3370]

true....or give the fan 24v & listen to the sound of an f18 about to take off LOL

to clarify, series wiring 2 fans would be as follows:

fan #1(+) to power input(+)
fan #1(-) ---> fan #2(+)
fan #2(-) ---> dc power input(-)

 

[reeformadness]

Sorry I missed the request for pics... here's a couple

 

[terahz]

Sorry I missed the request for pics... here's a couple

Reeformadness, nice setup, however I don't think it's a good idea to have active cooling on the bottom. Hot air raises up and most of the heat is dissipated from the top of the heatsink, you will probably benefit those from fans a lot more if they are on top.

THz

 

[reeformadness]

Something I will consider. I don't see any reason I couldn't change their position. They are doing their job however sice they only kick on at 65C and don't take too long to kick off. But I might try your idea. As they are now, they are forcing air out the top of the board through some vent slits. Here is a pic from the top...

 

[stugray]

reeformadness,

In that last pic, is that LIGHT I see coming from the LEDs thru the PCB?

why are the places where the LEDs are mounted brighter?

Stu

 

[reeformadness]

Yes, Stu. The light is coming through the thermal vias (little holes that help with cooling), fan vent slits, and some mounting holes. Yes you can see the LEDs directly a few posts up.

 

[sammy113]

Is there anyone that knows to work with Arduino that could point me around how much will I spend on doing a little system for my lights? Right now I have 12 LEDs but planning to upgrade to 24. Don't know chit about arduino and would like to know if someone could help and do it for me if possible and how much. Send PM please

 

[der_wille_zur_macht]

$30 - $50 if you're starting from scratch will get you a working prototype. It's pretty straightforward. Depending on how rugged you want the final version to be, and what features, you'll spend more. Shoot me a note if you want details.

Which reminds me, someone else on here wanted to see my code and I haven't sent it to them yet.

 

[AFWX]

Has anyone wired a couple LEDs for moonlight in their LED lights? If so, what LED, how many, and what size driver are you using?

I'm pretty sure it might me a little cheaper to just buy a moonlight, but I would like to build an all-in-one setup.

 

[reeformadness]

Depends on your tastes really but I would say 1-3 LEDs per foot of tank would be plenty. You would want to go with royal blue LEDs (rebels or crees). I can point you to a how-to if you need. The biggest hurdle you'd face would be if you wanted to program the lunar cycle. If that's what you want you'd be better buying a LED moonlight off of ebay. I can point you to the one I use if you want.

 

[der_wille_zur_macht]

IMHO moonlight LEDs should mimic your daytime lighting, as far as color spectrum. I can't find it now, but I remember an article by one of the reef lighting experts that pointed out that moonlight is very close to the spectrum of daylight on natural reefs.

Regardless of how many LEDs you use, you'll probably want them at a pretty low current. Even at 350mA, one HB LED is going to be pretty bright.

 

[AFWX]

Regardless of how many LEDs you use, you'll probably want them at a pretty low current. Even at 350mA, one HB LED is going to be pretty bright.

This is why I was thinking about something other than the CREE. Just from the pictures on this forum they look insanely bright. I'm not that familiar with LED options so I was looking for an LED that was much weaker. Or would it be better just to run one of the CREEs with a REALLY weak driver?

 

[terahz]

Is there anyone that knows to work with Arduino that could point me around how much will I spend on doing a little system for my lights? Right now I have 12 LEDs but planning to upgrade to 24. Don't know chit about arduino and would like to know if someone could help and do it for me if possible and how much. Send PM please

If your drivers have a dimming pin (like some of the 3021 buckpucks) and reference power of about 5V, all you need is one of the arduino boards (I have Nano 3.0 ~$35). Just connect the dimming pin to one of the digital pins that support PWM (check the documentation of the arduino board you get), then power the arduino from the reference power and you are all set. There is a LED dimming example in the arduino examples folder.

Here is my code, that accepts a single digit number from the serial console and gradually adjusts the level of the blue and white leds. I'm using digital pins 5 and 3 for my leds:

// pins used:
const int bluePin = 5;
const int whitePin = 3;

// initial brightness. 0 - off; 255 - max power
int lvl = 255;

int incomingByte;

void setup() {
  //setup serial IO
  Serial.begin(9600);
  
  //setup PWM pins
  pinMode(bluePin, OUTPUT); 
  pinMode(whitePin, OUTPUT);
  
  //setup initial brightness
  analogWrite(bluePin, lvl);
  analogWrite(whitePin, lvl);
}

void loop() {
  
  if (Serial.available() > 0) {
    
    // read a signel digit from the serial interface (0-9)
    incomingByte = Serial.read();
    
    //convert to int
    incomingByte -=48;
      
    // say what you got:
    Serial.print("Setting to lvl: ");
    Serial.println(255*incomingByte/9, DEC);
    
    //with 10 digits, we have 10 levels of brightness, adjust white and blue to the entered level:
    moveTo(255*incomingByte/9);
    lvl = 255*incomingByte/9;
    
  }

}

void moveTo(int value){
  int pval = lvl;
  int nval = value;
  Serial.print ("Prev is ");
  Serial.println(pval, DEC);
  Serial.print ("New is ");
  Serial.println(nval, DEC);
  
  
  if (pval > nval){
  Serial.println ("Decreasing");  
    for ( int a = pval; a > nval; a--) {
      Serial.println(a, DEC);
      analogWrite(whitePin, a);
      analogWrite(bluePin, a);
      delay(50);
    } 
  }
  if (pval < nval){
    
  Serial.println ("Increasing"); 
    for ( int a = pval; a < nval; a++) {
      Serial.println(a, DEC);
      analogWrite(whitePin, a);
      analogWrite(bluePin, a);
      delay(50);
    }
  }
}