General DIY LED thread

[oreo54]

first generate the data set in 5nm increments starting w/ 380.. Doesn't matter where you end
Axis in this case was 380-680
0-1 y axis.
Manually pick points (you can nudge w/ the adjust point.)
you also have a magnifier in the upper right corner of the working window..

view data ..formatting fixed 5 digits and hit format.
Copy to clipboard and paste it into Notepad++
Will need to save it before you can change it btw.

should go in as 2 columns x number of rows..
You will need to clean the data a bit.

All data points need to be like 500, 0.56

Save and import it into Spectra..

4000k Citizens COB:
380,0
385,0
390,0
395,0.009
400,0.012
405,0.012
410,0.015
415,0.02
420,0.038
425,0.074
430,0.137
435,0.24
440,0.4
445,0.622
450,0.904
455,1
460,0.794
465,0.57
470,0.473
475,0.41
480,0.388
485,0.43
490,0.487
495,0.558
500,0.616
505,0.667
510,0.706
515,0.729
520,0.746
525,0.768
530,0.791
535,0.816
540,0.84
545,0.863
550,0.881
555,0.891
560,0.894
565,0.892
570,0.882
575,0.874
580,0.867
585,0.862
590,0.863
595,0.868
600,0.881
605,0.902
610,0.925
615,0.949
620,0.966
625,0.983
630,0.993
635,0.993
640,0.983
645,0.962
650,0.931
655,0.895
660,0.847
665,0.799
670,0.74
675,0.679
680,0.626
685,0.562
690,0.505
695,0.447
700,0.396
705,0.352
710,0.307
715,0.272
720,0.235
725,0.205
730,0.175
735,0.148
740,0.128
745,0.11
750,0.091
755,0.077
760,0.068
765,0.055
770,0.046
775,0.038
780,0.035

 

[TDEcoral]

Thank you! To change the mW it looks like I would just download the .csv, edit it, then upload?

 

[oreo54]

Thank you! To change the mW it looks like I would just download the .csv, edit it, then upload?

Yes..
You need to adjust the lumens .. mW's will be calculated.. at least that's how I did it.
Trial and error to get the mW level I wanted..

well actually downloaded a "canned" diode in the nm range I wanted.. i.e download 420 "violet" and read the lumen vs mW data..

 

[Jer Davis]

Got home and tested on my Windows machine. Of course, that works. Thanks for your input! Would you have the PC Amber spectrum available to share?

 

[oreo54]

pcamber

 

[TDEcoral]

Just finished putting this 6 channel driver board together. This was my first time ever doing surface mount components and I used a skillet lol. I think the only issue is it looks like there might be a solder bridge on the pca9685 that I'll have to take care of.
The board is designed specifically for the 6x12" rapidled heatsink. It's got input for two temp probes and the heatsink fan.
Not pictured is the D1 Mini with the programming that'll control the lights through the Blynk app.

 

[Steven Garland]

So right now around my array I have 3 XP-E2 Royal,1 430 and 2 405's ran completely separate from the NB array.

How wise would it be to replace the outside diodes with 390-400,400-410,410-420 and a royal for a broad spectrum "actinic" channel ?



I threw this light together for a member on another for for his pico,but he didn't want it. 1 Orasm Cool White,2 405's and 2 Royals.

 

[TDEcoral]

What power supplies have people been using for the luxeon k16? I've been looking at the Meanwell LRS-200-48.

 

[AbjectMaelstroM]

I've been using LRS-350-48's. They're cheap, dependable and have a ton of gas. Depending on how much wattage you need, the 200 will do just fine.

 

[TDEcoral]

I've been using LRS-350-48's. They're cheap, dependable and have a ton of gas. Depending on how much wattage you need, the 200 will do just fine.

Do you calculate the wattage, amps, and voltage of your LEDs and try to closely match with the output of the PSU? I know doing so would increase efficiency and reduce heat, but I'm not sure what current I want to run my strings at yet. I'm thinking of just going with something like the LRS-350-48 so I have room to experiment.

 

[Steven Garland]

You may as well go bigger,better to have more head room to be safe.

 

[AbjectMaelstroM]

Do you calculate the wattage, amps, and voltage of your LEDs and try to closely match with the output of the PSU? I know doing so would increase efficiency and reduce heat, but I'm not sure what current I want to run my strings at yet. I'm thinking of just going with something like the LRS-350-48 so I have room to experiment.

Not really, I just calculated the overall headroom needed for my lights, which is about ~147w at full blast per fixture (x2 fixtures) and allowed a bit of wiggle room.

 

[skyrne_isk]

Hey guys, I'm about halfway through this thread and a lot of the conversation has been about color mixing and generally how to achieve a decently balanced color without too much reds (lime, etc). But for someone who is a neophyte with regards to electricity, can you point to a resource that would lay out the basic principles for how to design an LED fixture? I had thought to ask someone to just post their build process and/or parts list - but now I would rather get my head wrapped around how to DESIGN a light as opposed to how to BUILD a light.

Some of the concepts that would be super helpful:
1. like what mA to drive each type of LED
2. stay within limits of the driver
3. some lights appear to be linked to an app - how do you make that happen?

I have wired up T5's, VHOs and the like over the years but the concepts don't fully answer how to design LED arrays. I have replaced some diodes and parts on my LEDs as well - but again, this is quite a bit different than DIY.

Is there a thread already created that goes over this? Or could some of you guys who have been posting your designs here chime in?

 

[oreo54]

A Complete Idiot's guide to understand LED

For more such tutorials and fishy pictures, visit my website: www.playsofrays.com LEDs are the new ‘IN’ in the lighting world and so is i...

playsofrays.blogspot.com

Start there..
Only real thing one needs to know is
1)V(f) at your chosen drive current (based on what the diode is spec'd to take.. i.e "3W" class diodes could be run at anywhere from 1/2w to 3.2W based on the V(f) at the chosen current) times chosen current.

Sounds complicated but it isn't potential (voltage) changes w/ current.
3.6V(@ 700mA) @ 700mA = 2.52W
W = V X A

Next is to add up V(f)'s to match driver power supplies
10 diodes at 3.6 V needs a 36V power supply/driver
Will be 25.2W

Dimming type (adds to choice of driver) needed determines driver
2 MOST common:
10V analog (easy link to some controllers like Apex)
5V PWM most common controllers like Aduino and aduino like Storm, bluefish ect.

 

[skyrne_isk]

A Complete Idiot's guide to understand LED

For more such tutorials and fishy pictures, visit my website: www.playsofrays.com LEDs are the new ‘IN’ in the lighting world and so is i...

playsofrays.blogspot.com

Start there..
Only real thing one needs to know is
1)V(f) at your chosen drive current (based on what the diode is spec'd to take.. i.e "3W" class diodes could be run at anywhere from 1/2w to 3.2W based on the V(f) at the chosen current) times chosen current.

Sounds complicated but it isn't potential (voltage) changes w/ current.
3.6V(@ 700mA) @ 700mA = 2.52W
W = V X A

Next is to add up V(f)'s to match driver power supplies
10 diodes at 3.6 V needs a 36V power supply/driver
Will be 25.2W

Dimming type (adds to choice of driver) needed determines driver
2 MOST common:
10V analog (easy link to some controllers like Apex)
5V PWM most common controllers like Aduino and aduino like Storm, bluefish ect.

Ah, is this the same as "forward voltage"? Believe I have read up on that before. And I will check out the guide - I knew someone would have it handy

 

[oreo54]

Ah, is this the same as "forward voltage"? Believe I have read up on that before. And I will check out the guide - I knew someone would have it handy

Yes .. Each diode has sort of a pair.. voltage at a part. current..
It's a bit more complicated but it's the main metric in determining string size and power supplies..

IV curves | LEDnique

A device's IV (current versus voltage) curve graphs the relationship between current through a device and the voltage across it. Read and understand!

lednique.com

note small changes in voltage to the LED can create large changes in current (and heating)

 

[naoki]

Some of the concepts that would be super helpful:
1. like what mA to drive each type of LED
2. stay within limits of the driver
3. some lights appear to be linked to an app - how do you make that happen?

It depends on the goal, but my first priority is the efficiency since Alaskan electricity is pretty expensive. You need to understand several basic things about LEDs. The manufactrurers recommend maximum current as well as nominal current. With higher current, there are more light output, but the efficiency becomes low (more heat generated). So to maximize efficiency, you want to use as low current as possible. Then you need to have more diodes to get the same amount of output, so the initial cost becomes more expensive. So the design is the appropriate balance between the initial cost vs the long term cost (initial + electricity cost). The nominal current which manufacturers recommend is based on application of light which is used for shorter duration per day. So in general, we get a better deal by using lower current than the nominal (the benefit depends on the cost of electricity).

Then after deciding the driving current, there is the AC/DC conversion efficiency in the constant current driver. The driver can supply the constant current within a range of voltage (say 18-36V). The conversion efficiency becomes lower if you are not completely utilizing the capacity (i.e. you only need 18V to drive LEDs instead of 36V). So you want to design your system so that the driver isn't oversized.

Heat dispersion is another aspect of design. With active cooling, you can achieve lower operating temperature of LEDs, which increases the efficiency. I used to do it, but now I prefer with passive cooling with greatly under-driven LEDs for the simplicity and eliminating the failure point (fan).

Also, the dispersion of light is another factor in design. If you have a point source light, it creates harsh shadows so the lower branches of corals don't receive light. So a wider emitting surface like fluorescent light can increase the productivity. The advantage of scattered light has been demonstrated in plants, and it should apply to corals, too. So I recently prefer linear modules of med-power LEDs over a fixture with a few high power LEDs. Similarly placing the fixture closer to coral with a wider beam angle (instead of narrow beam angle from far away) can achieve the similar effect. But this close placement of the fixture causes the large difference in photosynthetic photon flux density (PPFD) between the top and bottom of the aquarium.

Here is one of my blog posts which talks about these issues and how to match drivers to LEDs: http://orchidborealis.blogspot.com/2016/11/led-driver.html

 

[oreo54]

Excellent post .....
Only thing I may add is in regards to ps's and separate drivers such as Ldd's..
Your need to be THAT specific on output utilization is sometimes unnecessary as long as one keeps it "reasonable".
anything like 45-100% "utilization" w./ the below ps is.. eer ...usually "good enough" for most.
Ldd's being switching in nature are quite efficient 97% @ full load..
Though that too is a bit tricky..

One can relatively easily design a super efficient array but you would need to know (measure) the exact parameters of the very diodes you picked.. From real v(f) to lumen efficiency vs current...

mostly added the above since you really concentrated on "all in one" drivers.
Power supply plus driver is also an option and very common if one doesn't need 10V analog/10V PWM or pot dimming..

 

[TDEcoral]

Can anyone give me some direction on uploading SSLAC16 to a wemos d1 mini (ESP8266)? I'm somewhat familiar with ArduinoIDE and have uploaded a different program to my d1 mini, but I'm not sure where to start with SSLAC16. I've already downloaded the project zip file.

@Kampo I think I saw you have used it before?

 

[Halo_003]

Not really, I just calculated the overall headroom needed for my lights, which is about ~147w at full blast per fixture (x2 fixtures) and allowed a bit of wiggle room.

Same here, I did a 240W power supply and 4x 48W arrays. On normal settings I probably stay below 120W but I wanted overhead.