Stealthy LED Project - help wanted

[Jopedijoo]

Hi guys!

Hi guys!

I'm back. I'm quite slow mo' as you can see but now the stones are rollin' again...

How has it been, how are you doing?

I had bad luck with missing on ordering those 15w 660nm reds. But as I was busy with real world things, :friends: and my luck changed.. Found two more of those reds and got back in the business!

I epoxied 2x15w warm whites, one on each heatsink, for testing and for future plans. Not going to be using those the first time. Need more reds to balance those whites. Soldered and tested:

Volts: 14.6 14.7 14.8 14.9

WW1: 1.20A 1,29A
WW2: 0.95A 1.00A 1.05A 1.11A

I could propably drive blues at 14.6V or 14.7, does that sound good?

Then I epoxied 2x15w 450nm blues, one on each sink. Soldered and tested:

Volts: 14.6 14.7 14.8 14.9

B1: 0.99A 1.05A 1.10A 1.17A
B2: 0.93A 0.99A 1.05A 1.10A

Here 14.7V or 14.8V is good, right?

Epoxied 8x15W 660nm reds, four on each sink. Soldered and tested. Not sure but I think I got crappy bins for these reds. Correct me if I'm wrong.

Volts: 9.7 9.8 9.9 10.0 10.1 10.2

R1: 0.93A 1.01A 1.07A 1.16A 1.22A 1.29A
R2: 1.05A 1.16A 1.22A 1.22A 1.30A
R3: 1.03A 1.10A 1.17A 1.25A 1.32A
R4: 1.13A 1.21A 1.30A 1.38A
R5: 1.00A 1.07A 1.14A 1.21A 1.29A
R6: 0.90A 0.99A 1.07A 1.14A 1.21A 1.29A
R7: 1.08A 1.19A 1.24A 1.32A
R8: 1.00A 1.04A 1.13A 1.19A 1.29A

Now, I was thinking that I could use two Meanwell PLN 60-12s two drive these reds. Maybe at 10.1 volts have R1(1.22A=12.32W), R5(1.29A=13.03W), R6(1.21A=12.22W) and R8(1.29A=13.03) and having 50.6W power consumption. Is that cool?

For the other PLN at maybe 9.9 volts have R2(1.22A=12.08W), R3(1.17A=11.58W), R4(1.30A=12.87W) and R7(1.27A=12.57W), having a 49.1W load there. Is good, or no?

I remember something about maybe having the emitters that draw most current at the end of the power feed.. Was that something you might have had said or am I just making up stories..?

I got some wire from a friend for this project. Got two kinds, 14 gauge and 20 gauge to use as Giblets suggested, 3-4 inches of 20 gauge from the emitter to a screw terminal to 14 gauge. I had my doubts about that 20 gauge wire because it didn't have any markings and I didn't have anything to measure it with. But I used it anyways and it has worked no problems so far. I haven't connected the emitters together yet though so there hasn't been more load than 1.4A or so. I turned out that the wire is probably more like 24 gauge. Do you think that's good enough or should I change it for fatter wire?

 

[Weezard]

You W*rk too hard.

You W*rk too hard.

OK, I'm way too medicated to slog through numbers tonight.
Giblets is better at that anyway.

But, on the wire size.
AWG 20 will carry one ampere with negligable voltage drop.

And that, tells you how to determine if you need fatter wire.
Just measure the voltage at each end of the wire when it's under load..
(Mo' betta dan a burned finger, yah?)

Then apply ohm's law.
Say, you find a .2V. drop on 8" of wire?
And you are pulling 1.25 Amps through it.
Le's see, <scritch> <mumble>, (carry da rhombic root), should be summat like .16 Ohms.
An' .25 Watts wasted as heat.
Unless, you want a .2 V. drop, you'll need a lower gauge wire.

And yes, I did purposly use a smaller gauge wire on parts of Frankenlight to drop a few tenths of a volt.
Just treated short runs of it as a 0.1 ohm "un-wound wirewound" resistors.
I was using Voltage limit supplies, so I had to jump through hoops.


As to all the VF. readings?
Yer workin too hard brah!

You are using Current limit, power supplies here.

Just set the current to 1.25 Amperes for a series string of emitters.
Each emitter will get 1.25 Amps, and the voltages will be whatever they be.
(R3 will be 10.0V. fer instance.)

As long as none of your emitters exceed any of their MAX limits, you are done.

It's really that simple with current limit supplies.

Aloha,
Weezard

 

[giblets]

Volts: 14.6 14.7 14.8 14.9

WW1: 1.20A 1,29A
WW2: 0.95A 1.00A 1.05A 1.11A

I could propably drive blues at 14.6V or 14.7, does that sound good?

Yes, that's fine. You're talking about the whites, (not blues) though, right?

Then I epoxied 2x15w 450nm blues, one on each sink. Soldered and tested:

Volts: 14.6 14.7 14.8 14.9

B1: 0.99A 1.05A 1.10A 1.17A
B2: 0.93A 0.99A 1.05A 1.10A

Here 14.7V or 14.8V is good, right?

I'd test those blues alla way up to 1.3A. You're safe driving them at 14.8V but you can crank them up still further if you need to fight stretch... Seems like I'm either doing that, or I've got them backed way down for normal flower lighting. I don't run 'em much in their "normal" range...they're either cranked or barely idling, but that's just me.

Epoxied 8x15W 660nm reds, four on each sink. Soldered and tested. Not sure but I think I got crappy bins for these reds. Correct me if I'm wrong.

Volts: 9.7 9.8 9.9 10.0 10.1 10.2

R1: 0.93A 1.01A 1.07A 1.16A 1.22A 1.29A
R2: 1.05A 1.16A 1.22A 1.22A 1.30A
R3: 1.03A 1.10A 1.17A 1.25A 1.32A
R4: 1.13A 1.21A 1.30A 1.38A
R5: 1.00A 1.07A 1.14A 1.21A 1.29A
R6: 0.90A 0.99A 1.07A 1.14A 1.21A 1.29A
R7: 1.08A 1.19A 1.24A 1.32A
R8: 1.00A 1.04A 1.13A 1.19A 1.29A

Now, I was thinking that I could use two Meanwell PLN 60-12s two drive these reds. Maybe at 10.1 volts have R1(1.22A=12.32W), R5(1.29A=13.03W), R6(1.21A=12.22W) and R8(1.29A=13.03) and having 50.6W power consumption. Is that cool?

For the other PLN at maybe 9.9 volts have R2(1.22A=12.08W), R3(1.17A=11.58W), R4(1.30A=12.87W) and R7(1.27A=12.57W), having a 49.1W load there. Is good, or no?

Yes, exactly right! When you first flip the plants to 12/12 and they try to stretch, you may want to run the reds lower while maxing your blues. Once you're solidly in flower, crank those reds as high as you dare and back the blues down...but you've got them "binned" together / matched correctly IMO.

I got some wire from a friend for this project. Got two kinds, 14 gauge and 20 gauge to use as Giblets suggested, 3-4 inches of 20 gauge from the emitter to a screw terminal to 14 gauge. I had my doubts about that 20 gauge wire because it didn't have any markings and I didn't have anything to measure it with. But I used it anyways and it has worked no problems so far. I haven't connected the emitters together yet though so there hasn't been more load than 1.4A or so. I turned out that the wire is probably more like 24 gauge. Do you think that's good enough or should I change it for fatter wire?

I only ran the lighter wire to protect the LED (thermally and mechanically) during soldering and mounting. An inch or three ain't gonna matter if you're running all your 15W leds in parallel, which you should be. (Look at how small the copper trace on the flex-pcb is; it's able to handle the current.) But in general, I like to use as large wire as possible. If you've got any question about the current-handling capacity of any of your wiring, replace it with something known. What's a few inches of quality 20 ga cost, anyway? Pennies? Not worth the potential problems.

 

[giblets]

You are using Current limit, power supplies here.

Just set the current to 1.25 Amperes for a series string of emitters.

But JJ should be wiring all the 15-watters in parallel. Each led is gonna be driven at the (same) selected voltage, which will drive the "softer" leds to draw more current than the "stiffer" ones, yes?

[Unless you're referring to the fact that each 15W led is actually (4) 5W emitters internally connected in series. (So, in a way, each 15W led is its own "series string.")]

 

[Weezard]

But JJ should be wiring all the 15-watters in parallel. Each led is gonna be driven at the (same) selected voltage, which will drive the "softer" leds to draw more current than the "stiffer" ones, yes?

[Unless you're referring to the fact that each 15W led is actually (4) 5W emitters internally connected in series. (So, in a way, each 15W led is its own "series string.")]

See, tol' ya Giblets was da one to ask.

Wee late night zard

 

[Jopedijoo]

Yei!

Yei!

Thanks Giblets and Weezard, once again! That pretty much covered it all, cheers I should be getting those Meanwells this week and then I'm finally done, before the real deal that is. I'll try to post a pic or two of the light once it's working... In a while crocs..

 

[whatissixbynine]

.

 

[Jopedijoo]

now i dont mean to be picky... but where's all the pics?!?

Anyway looks like your project is getting quite exciting over there; good luck!!

Hi 54! I'll post pics once everything is working properly, shouldn't be too long... Hang on there!

 

[Jopedijoo]

Los Problemos...

Los Problemos...

Once again I though I got it all... The Meanwells finally arrived today which is good. What is not is that turned all the way down the other one gives 10.7V (10.67) and the other 10.6V (10.56)! Damn it I say!! The other once should have 9.9V and the other 10.1V. That's max for those reds! What is to be done here? Resistors? Something else? Lucky to have the Mastech, would've destroyed those LEDs without it!

 

[Jopedijoo]

one-twoo-tree

one-twoo-tree

I've been testing the LEDs a bit today and it's been fruityfullytruely. I was just playing so I connected the blues and the whites together and run them with the Mastech. I run them conservatively at 14.7V. I was wondering cause I didn't get enough amps according to my readings when tested the LEDs one by one. So I stick the volt meter at every LED and there there.. at the first LED 14.71V, second 14.53V, third 14.42V, last 14.32. There is quite a lot of voltage drop I'd say. Could it be due to the thin wire at around 24 gauge?

Actually in this case it turned out good, if I ever want to drive those blues and whites with the same driver and that wiring. I put the LEDs in different order, the LED pulling least amps first and the one pulling most the last. This way I could turn voltage higher and it would drop some for the ones following so that they would roughly all get 1.3 amps.

The reds I didn't test this way yet, but I think I might want to replace some of the thin wiring for fatter because the the reds are quite alike and can't play with them the same way as with the blues and whites.

Is there always a voltage drop or should what be taken care of with fatter wire?

 

[Weezard]

Once again I though I got it all... The Meanwells finally arrived today which is good. What is not is that turned all the way down the other one gives 10.7V (10.67) and the other 10.6V (10.56)! Damn it I say!! The other once should have 9.9V and the other 10.1V. That's max for those reds! What is to be done here? Resistors? Something else? Lucky to have the Mastech, would've destroyed those LEDs without it!

I see by your next post, that you already figured it out.
See ya there.
W.

 

[Weezard]

Dat's not trouble, dat's a glitch.

Dat's not trouble, dat's a glitch.

In software jargon.
"One man's bug is another man's feature."
In Mandarin.
Chaos = Opportunity
In Homespunk.
Silver lining, Lemonade, Ill-wind..., yada yada.

I've been testing the LEDs a bit today and it's been fruityfullytruely. I was just playing so I connected the blues and the whites together and run them with the Mastech. I run them conservatively at 14.7V. I was wondering cause I didn't get enough amps according to my readings when tested the LEDs one by one. So I stick the volt meter at every LED and there there.. at the first LED 14.71V, second 14.53V, third 14.42V, last 14.32. There is quite a lot of voltage drop I'd say. Could it be due to the thin wire at around 24 gauge?

Rezackery!
Thin wire + high current = a drop in V.

Actually in this case it turned out good, if I ever want to drive those blues and whites with the same driver and that wiring. I put the LEDs in different order, the LED pulling least amps first and the one pulling most the last. This way I could turn voltage higher and it would drop some for the ones following so that they would roughly all get 1.3 amps.

The reds I didn't test this way yet, but I think I might want to replace some of the thin wiring for fatter because the the reds are quite alike and can't play with them the same way as with the blues and whites.

Is there always a voltage drop or should what be taken care of with fatter wire?

The drop will be proportional to the current and inversely proportional to the resistance of the wire.
It also represents a power loss, converted to heat.

A adjustable, current limit, power supply is the right tool for this job.

Da Weeze always says.
"When dealing with invisible forces, assumptions are ill-advised."

Wanna rush in blindly?
Bring some ketchup fo' da fries.

Ask D.H. 'bout dat.


You got no wolves here, mate.
I'll suggest you cogitate,
Onda game wit' da white an' da blue.
Ima play chess while you think it through.


I think you're doing a superb job here.

Aloha,
Da Weeze

 

[Jopedijoo]

Thank you Weeze! It has been a great project, at times I'm too lazy to lift a finger and like now I'm maybe too anxious to get the job done that I might start to blow LEDs up here Well, hopefully not...

I played around some more. Took some three feet of that presumable 24 gauge wire and pulled it from the Mastech and tried the same set of blues and whites. I had to turn the Mastech up to 16.34V to get 15.20V at the first emitter. The following emitters behaved as before. So the voltage drop using that this wire is more than a volt! That's probably good news..

I'm trying to protect my extinct red babies til the end but now I THINK I know what to do. The current limiter didn't kick in on the Meanwell so I'm not positively sure which way to turn the screw, which way is more and which way is less, but I guess I have to assume it works the same way as the voltage screw. With the same long thin wire I powered the blues and the whites using the Meanwell. As the PLN 60-12 is not really sufficient for the blues and the whites the voltage drop wasn't as big as when worked with the Mastech. Turned down the Meanwell gives 10.56 and there is NO voltage drop at all, even at the last emitter! The LEDs light but the current load is minimal so I guess that's why. When turned all the way up the Meanwell gives 13.23V and 12.93V at the first emitter so the voltage drop is roughly 0.3V. I need more drop for the reds, not much but some more.

I figure if I use the thin wire, turn the current limiter all the way down (the data sheet says you could turn it down 25%= 5A-25%=3.75A...??) and the voltage down too to 10.56V. Now if I understand correctly once there is enough current the voltage should drop on it's way to the first emitter.. If not, bye bye reds! Not one of them can handle 10.6V! The current limited SHOULD keep it safe, but as I can't test it properly I can't be sure...

Do I seem to be thinking strait here? If I could get more 15W reds no problem I could just give it a go.. Now that they are obsolete, I don't want to mess things up here...

 

[Weezard]

Thank you Weeze! It has been a great project, at times I'm too lazy to lift a finger and like now I'm maybe too anxious to get the job done that I might start to blow LEDs up here Well, hopefully not...

I played around some more. Took some three feet of that presumable 24 gauge wire and pulled it from the Mastech and tried the same set of blues and whites. I had to turn the Mastech up to 16.34V to get 15.20V at the first emitter. The following emitters behaved as before. So the voltage drop using that this wire is more than a volt! That's probably good news..

Easy enough to do.
Longer wire = higher R.
Double the length, double the resistance.
Given a tape measure and some wire snips, one can build any value one needs.
Just dont coil it!
That would create inductance and generate a spike with high current "off n onnies".

I'm trying to protect my extinct

Merely endangered

red babies til the end but now I THINK I know what to do. The current limiter didn't kick in on the Meanwell so I'm not positively sure which way to turn the screw, which way is more and which way is less, but I guess I have to assume it works the same way as the voltage screw. With the same long thin wire I powered the blues and the whites using the Meanwell. As the PLN 60-12 is not really sufficient for the blues and the whites the voltage drop wasn't as big as when worked with the Mastech. Turned down the Meanwell gives 10.56 and there is NO voltage drop at all, even at the last emitter! The LEDs light but the current load is minimal so I guess that's why.

Quite correct!

When turned all the way up the Meanwell gives 13.23V and 12.93V at the first emitter so the voltage drop is roughly 0.3V. I need more drop for the reds, not much but some more.

I figure if I use the thin wire, turn the current limiter all the way down (the data sheet says you could turn it down 25%= 5A-25%=3.75A...??) and the voltage down too to 10.56V. Now if I understand correctly once there is enough current the voltage should drop on it's way to the first emitter..

Quite correct, again.

If not, bye bye reds! Not one of them can handle 10.6V! The current limited SHOULD keep it safe, but as I can't test it properly I can't be sure...

Start with low current and increase it while you monitor the Vf. at the emitter with a digital voltmeter.

If you exceed Vmax, current will rapidly drop to zero.


Do I seem to be thinking strait here? If I could get more 15W reds no problem I could just give it a go.. Now that they are obsolete, I don't want to mess things up here...

Of course!
But, I'm guessing Ledengin will make another run if asked.
Unless your measurements on this last batch indicate that they are having problems with multi-die fabrication.

Giblets got your SOS and is prolly composeing a reply while I rattle on.


So...

Aloha,
Weeze

 

[giblets]

First, be cautious about "spiking" the leds with static electricity, or by doing a "hard disconnect" by just removing the wires from the diode. Power down by unplugging or shutting down your power supply. They are designed to "let the leds down easy."

With that precaution in mind, you can troubleshoot the voltage drop across any of your tiny wires by (temporarily) running a heavy wire right along with it. That way you can leave your original wiring intact; the electricity will take the easiest path--the fatter wire--and if your voltage drop vanishes, it was the resistance of the small wire that was causing the drop. I'd like to see a photo or schematic of how you're laying this out. Any drop in voltage due to the length of a small resistive wire should have some correlation to how long that wire is. Longer wire = more drop, disregarding deviation attributable to current variance, etc.

As for the minimum voltage setting on the Meanwells: do you have BOTH adjustments dialed all the way down? (Voltage limit and current limit?) BTW, clockwise increases, CCW attenuates on both features. You will see some interaction there.

Also, what is the input voltage configuration? Are you running 120V AC (like the US) or 220-240 or something else? With a higher input voltage the PLN60-12's may not adjust downward as far.

I've spoken to ledengin within the last 2 weeks. The 660nm 15W emitter is NOT "obsolete." That's just what Mouser calls something when they don't carry it any more.

When you deliberately run (too) thin wire for a distance you are functionally creating your own resistor. I think I'd rather run a short length of nichrome wire, or use a small value resistor, to achieve the desired voltage drop. Remember that as the temperature changes, the electrical characteristics of your components will change as well.

 

[Jopedijoo]

Thanks again Weeze and thank you Giblets!! I guess I've got some anties in the panties, didn't have the patience to go the safe way... But it turned out a'okey. Will get to that in a sec, but first things first..

First, be cautious about "spiking" the leds with static electricity, or by doing a "hard disconnect" by just removing the wires from the diode. Power down by unplugging or shutting down your power supply. They are designed to "let the leds down easy."

I've been trying to play it safe, so far so good. I was a bit worried in the beginning when turning off my Mastech. The LEDs that are connected all flash for a fraction of a second when turned off by the power switch (first turned voltage all the way down). Do you get the same thing? It doesn't happen with the Meanwells.

As for the minimum voltage setting on the Meanwells: do you have BOTH adjustments dialed all the way down? (Voltage limit and current limit?) BTW, clockwise increases, CCW attenuates on both features. You will see some interaction there.

Also, what is the input voltage configuration? Are you running 120V AC (like the US) or 220-240 or something else? With a higher input voltage the PLN60-12's may not adjust downward as far.

That's what I thought, clockwise is mo', CCW is less - thanks for clearing that up!

Yes, my input voltage is 220-240V. I have no clue, but as you said that could be the reason for me not being able to adjust as far down as you do.

I've spoken to ledengin within the last 2 weeks. The 660nm 15W emitter is NOT "obsolete." That's just what Mouser calls something when they don't carry it any more.

Well, maybe they are not exactly extinct, but it sure looked that way when I tried to order a couple more after they became obsolete at Mouser. Tried maybe five different distributors before I found the missing two emitters. So maybe they are not extinct in theory, but in practice.. I guess if you'd order hundred pieces it would be different.

When you deliberately run (too) thin wire for a distance you are functionally creating your own resistor. I think I'd rather run a short length of nichrome wire, or use a small value resistor, to achieve the desired voltage drop. Remember that as the temperature changes, the electrical characteristics of your components will change as well.

I don't know how resistors work and how to calculate what you need, but now I do have a poor man's resistor, the thin wire. It's working good, temporary at least. What would happen in the summer as things heat up, don't have a clue..?

Well, what I did today was similar what I did with the blues and the whites. I took two sets of reds and lined them up: R6, R8, R3 and R4 in the other "line" and R1, R5, R2 and R7 in the other. Could have done it some other way also, but this is how it is for now. Notice the voltage drop. I powered each combo with the Mastech:

R6(10.2V, 1.29A), R8(10.0V, 1.19A), R3(9.9V, 1.17A) and R4(9.8V, 1.21A)

Tried the same set also with slightly higher voltage:

R6(10.3V, 1.37A), R8(10.1V, 1.29A), R3(9.95V, 1.25A) and R4(9.87V, 1.30A)

The other set was tested likewise:

R1(10.2V, 1.29A), R5(10.02V, 1.21A), R2(9.83V, 1.16A), and R7(9.75V, 1.19A)

With higher voltage:

R1(10.3V, 1.38A), R5(10.08V, 1.29A), R2(9.92V, 1.22A) and R7(9.83V, 1.19A)

Maybe it would be possible to arrange the reds better, I still have to think that through, but it's close. The first set I forgot to test how much voltage the Meanwell is putting out before the "thin wire resistor", but the second set at 10.3V at the first emitter gives 11.53V before the thin wire.

I don't have a digital camera of my own, but I'll try to get one borrowed over the weekend, might post a few pics if I'm lucky... See ya!

 

[atlashomeric]

Hey Weezard, I've been following your posts concerning LEDs now on this site and a few others for almost a year. I finally decided to take a leap of faith and build an LED panel using higher watt emitters such as 5w and 10w. I'm working closely with a plant physiologist professor at a near by university here in California concerning light color ratios and their effectiveness. Currently we're designing a new LED that I think is going to produce results comparable to the higher wattage HIDs, however, having read through so many of your posts I have a few questions about using higher wattage emitters: in your opinion do you think that a (8) 5 watt emitters has the same penetration as one 40 watt emitter, or even (4) 10 watt emitters has the same as one 40 watt emitter? We're using LEDengin's emitters and running them close to their Imax. I'll leave this as my first question. Thanks for being one of the first to pioneer LEDs into horticulture bro.

 

[Weezard]

Dave's not here and niether am I. Y'all know why.

Dave's not here and niether am I. Y'all know why.

I would love to see a 40W. emitter.
Give me 4. 40W 660s and a couple 30W. blue emitters with a dimmer, and Ill grow ya some trees.

By now, you've seen da PM.
BCNU?

Weeze

 

[Jopedijoo]

Is two lamps...

Is two lamps...

I'm in a bit of a hurry, but here's a pic of the first test with all emitters light, full throttle Hope it works! I'll try to post more pictures tomorrow...

http://www.icmag.com/ic/album.php?albumid=15902

 

[Weezard]

I'm in a bit of a hurry, but here's a pic of the first test with all emitters light, full throttle Hope it works! I'll try to post more pictures tomorrow...

http://www.icmag.com/ic/album.php?albumid=15902

That link , does not link.
Drat!

Weeze