Cheap LED Strips : A Viable Alternative

[Gpaw]

@funkyfunk

The other is that I could dim differently two sides of the cabinet (if I ever wish so, that’s more of a bonus).

That’s cool, here’s another idea, instead of 4 strips at 3500K, 2 strips of 3000K & 2 strips of 4000K (lets you ‘fiddle’ the spectrum a little). Of course I thought of that after I built my light…

@funkyfunk

Or would I get the same “low” voltage if I was running a 120W driver with 2 pairs of strips in series wired in parallel

You would get the same voltage for the same strip configuration, the only difference would be you would need twice the current for the single driver configuration.
The extreme configurations would be 4 strips in parallel & 4 in series.
4P would need 4.2 A at 27 Vdc (single driver)
4S would need 1.050 A at 108 Vdc.
You want to be careful dealing with 108 Vdc as that could be lethal…
(If I’ve confused you with any of this please ask questions to clarify)

@funkyfunk

I was willing to simply use aluminium strips to mount them and as a cheap cooler. Do you think I should go for aluminium angle rather?

I used aluminum angle because it was convenient and matched the width of my LED strips. I’ve seen these sorts of LED strips mounted in all manner of ways, even baking pans. If it works, it works!

I think DigiKey (electronics parts supplier) delivers worldwide, you might want to use them for local price comparisons.
If you wish to electrically insulate the solder connections, have a look at “liquid electrical tape”. It’s a black ‘goop’ you dab on and it hardens up to form a rubber-like insulation barrier.

Oh yeah, don’t powerup the driver when it’s disconnected from the led strips… They are supposed to be OK doing this but a couple folks actually damaged theirs and had to replace.

Cheers
G

[funkyfunk]

Thanks again to take the time to help @Gpaw . Very much appreciate it

@Gpaw

That’s cool, here’s another idea, instead of 4 strips at 3500K, 2 strips of 3000K & 2 strips of 4000K (lets you ‘fiddle’ the spectrum a little). Of course I thought of that after I built my light…

How did you know my next question? That definitely makes sense now that you say it, I’ll go for that

@Gpaw

You want to be careful dealing with 108 Vdc as that could be lethal…
(If I’ve confused you with any of this please ask questions to clarify)

You’re helping me being rational rather. I think I’m getting it:

• 2 devices in series, double the voltage
• 2 devices in parallel, double the amperage

I’m trying to lower both, because

• low amperage = cooler and easier on the led
• low voltage = well, less chances to die.

That’s why I thought 2 drivers at first (reaching these goals and being able to dim differently)

But if I get it right, I could have the same voltage and amperage by using 2 pairs of strips in series, mounted in parallel on a 120W driver. I’d only loose the ability to dim only one pair of the led strips?

I will check driver prices now, I’m ready to loose this dimming agility for a price drop

@Gpaw

I used aluminum angle because it was convenient and matched the width of my LED strips. I’ve seen these sorts of LED strips mounted in all manner of ways, even baking pans. If it works, it works!

haha I bet! Cooling isn’t really sorted out I admit. I’ll probably follow your advice and try to find better than plain aluminium strips, depending on the prices.

@Gpaw

I think DigiKey (electronics parts supplier) delivers worldwide, you might want to use them for local price comparisons.

Yep I did look a bit there. They have a lot to propose, to the point I feel a bit lost even. I’m using torbrowser for this researches, don’t want “authority” to know I’m looking that much on “gardening leds” But they block torbrowser so it does not help searching there. I may get the driver(s) there still, they are difficult to source it seems and digikey has some.

@Gpaw

If you wish to electrically insulate the solder connections, have a look at “liquid electrical tape”. It’s a black ‘goop’ you dab on and it hardens up to form a rubber-like insulation barrier.

That’s good to know, I didn’t think about that yet, you’re filling the holes in advance and preventing possible mistakes

@Gpaw

Oh yeah, don’t powerup the driver when it’s disconnected from the led strips… They are supposed to be OK doing this but a couple folks actually damaged theirs and had to replace.

Crap! Having amplifiers, I’m used to devices needed to have a load plugged in otherwise they blow. I may have thought about that. But now I’m sure I will.

Thanks!

[Gpaw]

Just found this article:
From physics to fixtures to food: current and potential LED efficacy

https://www.nature.com/articles/s41438-020-0283-7

Interesting read…

Cheers
G

[Jdem075]

so I just built a 4x4 led light. I bought enough parts to make two. it doesn’t seem bright enough. here is what I bought and the finished light. both adjustments on the driver are all the way up.

what do you think of my light?

[Uprangewilly]

I like it. How did you wire it up? Parallel or series? Any pictures with it lit up?

[Jdem075]

it’s weird in parallel, he’s a pic on.

[Uprangewilly]

Looks good to me. Do you have a par meter or app? Can you comfortably look directly at it while it is on? Do you see spots after glancing at it?

[Jdem075]

I have a par meter on my phone, just don’t know how reliable it is. I definitely see spots after looking at it. when using the app on ppfd setting, it only shows 16k

[Tejas]

Nice job on the light. I use an app called Photone to check DLI and PPFD, it’s free. The only thing you need to do is cover the camera while using.

[Jdem075]

so I hung the light. I have some $80 store bought square lights that test about 750 ppfd at 12 inches. my light only gets to 175 at 12 inches. I’m confused.

[Jdem075]

I think I put twice the amount of strips on this driver. the strips are 23.5v and max voltage input is 305. am I wrong thinking that it will only power 12 strips? or is it a wireing issue? series instead of parallel?

[Uprangewilly]

The input side is for the wire coming from the wall. As long as your using regular 110volt outlet, your good. The lights effect the output side, and I believe your still in spec with the amount of strips you have.

Let me do some reading to see how people typically wire up that driver. I have not used a 480h in my builds. It should work in parallel, I wouldn’t change that.

[Jdem075]

I think I might have figured it out. there are two outputs from the driver. I used them both 12 and 12. I think I need to just use one or use them both for all the strips. I’ll check tomorrow

[Uprangewilly]

That’s one of the things I’m curious about as well.

[Gpaw]

Let me start by saying first, there might be nothing wrong… but here are some possible issues:

The spec. numbers suggest that you might be low on the DC supply voltage to the strips. (I’m not familiar with these, I used the Gen 2)

That’s the EB ‘edge’ series, 570mm long? Page 4 (Table #2) shows the min/typ/max forward voltage range to be: 21.9/ 23.5/ 25.1Vdc.

The HLG-480H-24 lists 24V @ 20A, so lots of current.
If you think the light output is low check the voltage across a strip. Anything below 24V should be OK.
You have the “A” option so there is a small adjustable pot (hidden under a protective cover) that you can use to tweak up the voltage to a max of 25.2 Vdc (if necessary).
Another possible issue might be the wire gauge. Each strip looks like 700mA (nominal) but there’s 24 strips so a total of 16.8A. Depending on how you are handling the ‘fan out’ you might be adding copper losses to the forward voltage. You should notice the wire being slightly warm if this is an issue. A solution to this would be to use a heavier gauge (16AWG) in the initial fan out.
I see they recommend 24~26AWG (page 9, table #5) so you definitely need heavier wire before the final fan out.

Here’s another thought for you, you could have the driver external to the tent (to remove that heat source)…

Cheers
G

[Jdem075]

yep, they are the eb edge series gen 3 570mm long
the driver is the A version, and i did adjust it up all the way.
i’m using 18 gauge for all the wires, so ill take a look at that.

the driver has two outputs to the LEDs. so this morning i tried to wire all 24 to one output, same result. then all 24 to both outputs, same result. then i tried only 12 strips in all the variations, same result. kinda stumped.

maybe since these LEDs are on row per strip, the LED density is an issue? all the other strip lights i see are 3 to 5 rows per strip. another thought is to connect one strip to the driver and see how bright it is. i just don’t want to burn it out.

[Gpaw]

@Jdem075

maybe since these LEDs are on row per strip, the LED density is an issue? all the other strip lights i see are 3 to 5 rows per strip.

There are lots of us that built them with various single strips, both gen 2 and gen 3 Bridgelux etc with good results…
I know the commercial units run multiple row strips (usually something like 100W each) but they are relying on serious thermal management to deal with the heat.
Usually we are using a “B” or “AB” driver models for the dimming feature.
Careful about running fewer strips with that model of driver. These strips and drivers are ‘constant current’ and that means the driver is going to try to ‘push’ max current (20A) independent of the number of strips. The strips have a max current rating of 1.4A ea. (nominal is 0.7A).

Maybe I’m missing something, perhaps @Mr.Sparkle could have a review and see if he has some insights I’m missing…

Cheers
G

[Uprangewilly]

Yeah, I’m stumped as well. I would definitely do like @Gpaw suggested and increase the thickness of the branch wires.
Have you tried the other driver?

[Natea]

Man, everytime I see people asking or explaining this electrical stuff, my mind shuts down lol. I am making my own light right now and hope I got everything right. Just waiting on a dimmer to come in the mail

[Mr.Sparkle]

been watching just time and such

So couple things, first just as a point the best edge gen3s are only as efficient as your normal eb2’s “175lm/w”, likely due to diode count, and layout ect.

The edges run bit higher voltage and in your case if your using that full 20a and 24 strips that puts it at 833ma approx each strip that will cause your forward voltage of each strip to jump up a bit say just north of 24v “24.2ish by the charts” so you will need to adjust that Vo potentiometer to supply more than the base 24v, say set it at 24.5-24.8 if you have a multimeter, really cause your current limiting the voltage will max out to a set point and even drop once things heat up, but that Vo setpoint will act as a second backup.

Should the output leads matter as for as how things are wired up, i dont think so as just seems to be same output as far as i can tell spec sheet wise for the 480’s so its just a convenience thing to provided two output leads but i could be wrong there.

As for the Io potentiometer if that was fiddled with you could be supplying too little current for what you want, so if you happen to have a wall watt meter thats the safest and easiest way to see if that driver is pulling and using what it needs and adjusting that Io pot to suit, Voltage can be measured directly with a multi meter, now consider though that 480w to the strips will mean about 510w from the wall as the driver is about 94% efficient on 120v.

18awg should be fine and you can look up info for that and consider your wiring as chassis wiring for, resistance and gauge sizing for amperage, the wago’s “quick connects” though… they work but fewer the better and the lower the amperage they have to see the better.

Now more into the meat of it.

How your measuring and what your measuring light wise, first consider what your measuring and how and the light design, so first if your not measuring in say a sealed reflective environment of course your numbers are gonna be low as all the light that fixture makes is being spread out by design and say filling the room around you, also a single strip of diodes wont have the spot intensity for say a light that has all its diodes in one place so your other lights could potentially seem brighter on your app at 12" directly under it but say a foot and half or two off center from that its likely a different story.

So if say that fixture is for a 4x4 tent, id test it in said tent or space first before measuring just to get a bit more tellign numbers, will it be as high as say a spot lamp no but its distributed so its a different story as it’s covering more area

but again go over the amperage and voltage stuff first and see if there is actually that 480w getting to the strips or being pulled from the wall, then measure in applicable environments so your results arent skewed.