LEDgardener

Hi,

I've been through a few resources in the community and I'm looking to get started with my first LED build. I'm going to build an herb box for my apartment, and I was planning to hang a single LED strip over the top.

The Plan
I was going to aim for a box about 24x8in in size, with 4 plants in square pots inside. Most likely basil, mint, lettuce, and maybe a small hot pepper or mini tomato plant (although I'm fine without if they require too much light). I was going to hang the light about 18in above the soil, and wire up a dimmer. Cost is not a huge concern since it's a relatively small build, so I don't mind spending a little more for better components. A few questions...

1. Will a single Samsung F-Series Gen 3 strip get the job done? Would the strip with the single row of LEDs be bright enough or do I need the double row?

2. I typically hear that 5000k+ lights are recommended for growing herbs. However, I was thinking about going with 4000k so the lighting isn't too blue but instead a little more pleasing to the eye in the house. Do you think this will be fine?

3. I'm debating how to mount the strip. I was leaning towards using an LED profile so it looks finished. I've had a bit of trouble trying to find LED profiles that fit these Samsung strips since most of the products seem to be designed to fit narrow flexible strips. I've seen some wider ones where I could probably mount a Samsung F-Series strip, but I'm now wondering about heat. There's obviously not much airflow inside an LED profile, and they usually contain strips that don't get very hot. If I mount a Samsung F-Series strip to a profile with thermal tape, and the profile is enclosed on the sides and with a diffuser, do you think it would overheat? Should I think about getting the wider strip mentioned above with more LEDs, and running them at less power? That brings me to my last question.

4. What driver should I go with for either of the above strips? I would like to wire up a dimmer and I know Mean Well has lots of options to choose from, but I'm a bit overwhelmed with the choices.

Thanks for any suggestions!

cg_grow wrote: ↑

Fri Jan 08, 2021 9:18 am

A few questions...
1. Will a single Samsung F-Series Gen 3 strip get the job done?
2. ... 5000k+, ... 4000k... Do you think this will be fine?
3. I'm debating how to mount the strip... do you think it would overheat? ... running them at less power?
4. What driver should I go with for either of the above strips?
Thanks for any suggestions!

1. Yes, a single Samsung F-Series double row 560mm Strip (LT-F564B) can provide adequate PPFD coverage for Veg to Flower.

2. Correlated Color Temperature (CCT) is a simplistic indicator of Percentage Wavelength Distribution, 5000K having more Blue (400 - 499 nm) wavelengths than 4000K, anything above ~ 3500K will have a "natural / normal" appearance and Color Rendering Index (CRI) above 90 will appear more "vibrant" while providing better Spectrum for growth due to increased Red (600 - 699 nm) and Far Red (700 - 780 nm) wavelengths... download/file.php?id=4521
The Bridgelux Vesta 2750 LED Strips can provide both high 90+ CRI and 2700, 4000 or 5200K CCT... download/file.php?id=4385&mode=view

3. Samsung and Bridgelux LED strips operating at less than 50% "Maximum Rated Amps" (< 0.5 * Max. Amps) require minimal to no heatsinking and can be easily mounted on Aluminum Sheet, Bar Stock or C-Channel, with the addition of a clear Plexiglass Lens that can decrease the light output by up to 10%.

4. Any LED Driver should be "Sized" to provide an adequate "Range" of output Watts, +/- the "req'd" Watts (+ = Reserve, - = Dimming). The -AB suffix XLG and HLG series Meanwell Drivers can be "Current Limited" down to 50% (-A) and then Dimmed between "10 - 100%" (-B), e.g., XLG-50-AB can be current adjusted down to 25 Watts (-A, 50%) and then also Dimmed 2.5 - 25 Watts (-B, 10 - 100%) with a connected 100K Ohm Pot.

Some Calculations:
24" * 8" = 192 / 144 (sq in) = 1.33 sq ft , ~ 1.5 sq ft or 0.15 m2
1.5 * 40 PPF (/sq ft for veg) = 60 PPF req'd
1.5 * 60 PPF (/sq ft for veg - flr) = 90 PPF req'd

60 PPF / 2.5 PPE = 24 Watts req'd
90 PPF / 2.5 PPE = 36 Watts req'd
12 - 36 Watts ~ 20 - 60 PPF per sq ft (200 - 600 PPFD)...
24 * 1.25 = 30 Watts (sized)
36 * 1.25 = 45 Watts (sized)

a. Selected LED Strips;
One (1) LT-F562B, F-series Gen 3, 560mm single row = 4500 Lm * 0.014 = 63 PPF @ 26 Watts

a. Selected Driver;
XLG-50-AB @ 24 Vdc... https://www.digikey.ca/en/products/deta ... QEIgF0BfIA


b. Selected LED Strips;
One (1) LT-F564B, F-series Gen 3, 560mm double row = 9000 Lm * 0.014 = 126 PPF @ 52 Watts (~ 79.8 PPF @ 30 Watts)

b. Selected Driver;
XLG-50-AB @ 45 Vdc... https://www.digikey.ca/en/products/deta ... QEIgF0BfIA
Or an XLG-75-H-AB @ 45 Vdc... https://www.digikey.ca/en/products/deta ... wCMQBdAXyA


c. Selected LED Strips;
Two (2) Bridgelux Vesta 2750 Gen 2, 560mm double row = 6400 Lm * 0.016 = 102 PPF @ 50 Watts (~ 73.5 PPF @ 30 Watts)
BXEB-TL-2750G... https://www.digikey.ca/en/products/deta ... 13/7899252
... download/file.php?id=4396
... download/file.php?id=4401

c. Selected Driver;
XLG-50-AB @ 24 or 48 Vdc... https://www.digikey.ca/en/products/deta ... QEIgF0BfIA
Or an XLG-75-H-AB @ 48 Vdc... https://www.digikey.ca/en/products/deta ... wCMQBdAXyA
(48 Vdc are wired in 2Series/1Parallel circuit... download/file.php?id=4687 )


Notes:
1. Grow Lights should be "Sized" by Grow Area and Plant Specific Growth Stage... download/file.php?id=4438

2. Nominal Efficiency of current LED Strips is 2.5 PPE and the LED Driver "Sizing" factor or multiplier used is 1.25 (125%) of the LED's Watts for "Reserve Capacity" .

3. Samsung and Bridgelux LED Strips run at or below 50% max current require minimal to no heatsinkining...
Samsung LT-F564B... viewtopic.php?f=32&t=5872
Bridgelux Vesta 2750G... viewtopic.php?f=32&t=5761

You're welcome.

I suggest 4000K CRI90 strips if available, more pleasing to the eye and more balanced spectrum

Thanks Peter, that post was really helpful. Would this configuration make sense?

One LT-F564B strip, F-Series Gen 3, 560mm double row
https://www.digikey.ca/en/products/deta ... WW/6624007

HLG-40H-48AB
https://www.mouser.ca/ProductDetail/Mea ... 52bUG2AQ==

I could run the driver at 100% for 0.84A or about 39W / 6750Lm from the strip (75% capacity for what the strip is rated). If it's still generating too much heat in my setup, I could then use the driver's built-in potentiometer to reduce those numbers all the way down to 0.5A if necessary. From what I understand I could then wire up a 100k ohm potentiometer with a 10k resistor to dim between 10-100% of the set values, and I don't have to worry about overheating when someone in my house turns the dimmer to 100% because I already have the maximum set on the driver.

Is that right? Do you think this would work well for what I'm trying to accomplish?

cg_grow wrote: ↑

Sat Jan 09, 2021 12:10 am

Thanks Peter, that post was really helpful. Would this configuration make sense?

One LT-F564B strip, F-Series Gen 3, 560mm double row
https://www.digikey.ca/en/products/deta ... WW/6624007

HLG-40H-48AB
https://www.mouser.ca/ProductDetail/Mea ... 52bUG2AQ==

I could run the driver at 100% for 0.84A or about 39W / 6750Lm from the strip (75% capacity for what the strip is rated). If it's still generating too much heat in my setup, I could then use the driver's built-in potentiometer to reduce those numbers all the way down to 0.5A if necessary. From what I understand I could then wire up a 100k ohm potentiometer with a 10k resistor to dim between 10-100% of the set values, and I don't have to worry about overheating when someone in my house turns the dimmer to 100% because I already have the maximum set on the driver.

Is that right? Do you think this would work well for what I'm trying to accomplish?

Yes, this configuration can work, just (10 watts) less "reserve" output...
85 Watts is ~ 100% (45 Vdc * 1.8 A) for the LT-F564B (SI-B8T521560WW)... 0.84 A is actually only ~ 46.6%... download/file.php?id=4516&mode=view
Samsung Calculator Tool... https://www.samsung.com/led/support/too ... alculator/

And Yes that is how all the -AB suffix LED Drivers function (XLG-xxx-AB and HLG-xxx-AB), added resistors are not required with XLG Series Drivers.
BTW, I prefer the XLG Series Specs and lower cost.
You're welcome.

PeteR_1 wrote: ↑

Sat Jan 09, 2021 1:14 am

Yes, this configuration can work, just (10 watts) less "reserve" output...
85 Watts is ~ 100% (45 Vdc * 1.8 A) for the LT-F564B (SI-B8T521560WW)... 0.84 A is actually only ~ 46.6%... download/file.php?id=4516&mode=view
Samsung Calculator Tool... https://www.samsung.com/led/support/too ... alculator/

And Yes that is how all the -AB suffix LED Drivers function (XLG-xxx-AB and HLG-xxx-AB), added resistors are not required with XLG Series Drivers.
BTW, I prefer the XLG Series Specs and lower cost.
You're welcome.

Oh, you're right, I misread your previous post and I was basing my calculations on the typ. 1.12A value and not the max 1.8A value. In that case I should go for a larger driver, and the two you suggested seem like the best match.

1. I'm looking over the specifications on the XLG models, and I'm a bit confused by "FULL POWER CURRENT RANGE". The XLG-50 specs say 1A RATED CURRENT, but then 0.53 ~ 2.1A FULL POWER CURRENT RANGE. From what I can see in the lower graph, "Recommend Performance Region", this means it can deliver 1A across the entire voltage range, and it can extend to 2.1A at lower voltages. If I connect the 46V strip and set the driver's built-in potentiometer to min power, will it deliver about 0.53A and max power would deliver about 1.1A?

2. Thanks for mentioning the 0-10V dimming on the XLG models, that's one thing I overlooked and it'll be a useful feature if I can dim the system to turn it off. There's no reason to have a power switch or to unplug the system overnight, and I can safely leave it dimmed to 0% for extended periods of time?

3. Does Samsung no longer make F-Series strips in 90 CRI? I noticed they had documentation for them, but I only see the 80 CRI versions for sale.

cg_grow wrote: ↑

Sat Jan 09, 2021 5:46 am

PeteR_1 wrote: ↑

Sat Jan 09, 2021 1:14 am

Yes, this configuration can work, just (10 watts) less "reserve" output...
85 Watts is ~ 100% (45 Vdc * 1.8 A) for the LT-F564B (SI-B8T521560WW)... 0.84 A is actually only ~ 46.6%... download/file.php?id=4516&mode=view
Samsung Calculator Tool... https://www.samsung.com/led/support/too ... alculator/

And Yes that is how all the -AB suffix LED Drivers function (XLG-xxx-AB and HLG-xxx-AB), added resistors are not required with XLG Series Drivers.
BTW, I prefer the XLG Series Specs and lower cost.
You're welcome.

Oh, you're right, I misread your previous post and I was basing my calculations on the typ. 1.12A values and not the max 1.8A values. In that case I should go for a larger driver, and the two you suggested seem like the best match.

1. You mentioned the XLG-50-AB and XLG-75-H-AB. Is there any reason to go for the XLG-75-H-AB if I don't plan on going above 1A? For example, would reducing the XLG-75-H-AB from 1.4A to 1A cause it to run noticeably cooler than the XLG-50-AB at the maximum of 1A?

2. Thanks for mentioning the 0-10V dimming on the XLG models, that's one thing I overlooked and it'll be a useful feature. If I simply dim it to 0% it'll turn completely off? There's no reason to have a power switch or to unplug the system overnight, and I can safely leave it dimmed to 0% for extended periods of time?

3. Does Samsung no longer make F-Series strips in 90 CRI? I noticed they had documentation for them, but I only see the 80 CRI versions for sale.

Got some good guys in here helping you already, but just wanted to point out the thrive strips as a possible higher cri option. You would need to get multiple strips, but three thrive strips is only a few dollars more than the one f-series strip on digikey. The thrive strips run at around 20V so your driver options will be a little different as well. Maybe something like the hlg-60h-24a if you decided to go this route since you would be limited to how you could wire just three strips, so no viable option using the xlg drivers and 3 of these strips. Again this would add a little extra to both the price and build, but something to check out as a possibility.

Sorry I found myself lurking around the forums and checking out some strips again. I am no great source of info, but figured I'd just throw it out there since there aren't too many readily available options in the 90+cri and small quantities it seems. I personally like the higher cri spectrums for the extra boost in red compared to the 80cri spectrums.

https://www.digikey.com/en/products/det ... 3/13181804 For reference in case you wanted to take a look.

cg_grow wrote: ↑

Sat Jan 09, 2021 5:46 am

Oh, you're right, I misread your previous post and I was basing my calculations on the typ. 1.12A value and not the max 1.8A value. In that case I should go for a larger driver, and the two you suggested seem like the best match.
1. I'm looking over the specifications on the XLG models, and I'm a bit confused by "FULL POWER CURRENT RANGE". The XLG-50 specs say 1A RATED CURRENT, but then 0.53 ~ 2.1A FULL POWER CURRENT RANGE. From what I can see in the lower graph, "Recommend Performance Region", this means it can deliver 1A across the entire voltage range, and it can extend to 2.1A at lower voltages. If I connect the 46V strip and set the driver's built-in potentiometer to min power, will it deliver about 0.53A and max power would deliver about 1.1A?
2. Thanks for mentioning the 0-10V dimming on the XLG models, that's one thing I overlooked and it'll be a useful feature if I can dim the system to turn it off. There's no reason to have a power switch or to unplug the system overnight, and I can safely leave it dimmed to 0% for extended periods of time?
3. Does Samsung no longer make F-Series strips in 90 CRI? I noticed they had documentation for them, but I only see the 80 CRI versions for sale.

The "Selected" larger Drivers are for future expansion or to increase output to overcome any losses due to Miscalculations, Voltages, Lenses, etc. Also all LED Drivers will run cooler (measured temperatures at Driver Tc) below their max rated outputs, e.g., the 50 Watt Driver outputting 50 watts will be operating warmer than the 75 watt driver at 50 watts output, I've measured a noticeable Driver Tc difference (increased temps) above ~ 85% max output.

1. Yes, The XLG-50-xx has a full 50 Watts output at 24 - 54 Vdc (page 3 of the specs), Max output... 24 V * 2.1 = 50.4 Watts to 54 V * 1 = 54 watts, the Adjusted Min at the (-A) internal pot is ~ 50% of Max. BTW my Primary selection criteria for LED Drivers is Output Watts (CC) and then DC Voltage not Amps. IMO selecting for Amperage will create a more difficult "Moving Target" when properly sizing the LED Driver.

2. IMO a switch or "supervised" contact (Timeclock, Relay, etc) should always be used for a true "Off" or positive disconnect.

3. Don't know, have not seen any available 90 CRI F-Series, but am a newbie to LED Strips.

wuwuorganics wrote: ↑

Sat Jan 09, 2021 7:37 am

Got some good guys in here helping you already, but just wanted to point out the thrive strips as a possible higher cri option. You would need to get multiple strips, but three thrive strips is only a few dollars more than the one f-series strip on digikey. The thrive strips run at around 20V so your driver options will be a little different as well. Maybe something like the hlg-60h-24a if you decided to go this route since you would be limited to how you could wire just three strips, so no viable option using the xlg drivers and 3 of these strips. Again this would add a little extra to both the price and build, but something to check out as a possibility.

Sorry I found myself lurking around the forums and checking out some strips again. I am no great source of info, but figured I'd just throw it out there since there aren't too many readily available options in the 90+cri and small quantities it seems. I personally like the higher cri spectrums for the extra boost in red compared to the 80cri spectrums.

https://www.digikey.com/en/products/det ... 3/13181804 For reference in case you wanted to take a look.

Thanks for the suggestion on the strips. Let's say I did go with a higher number of strips and a larger build, such as...

5x EB Series Gen 3 Thrive
https://www.digikey.com/en/products/det ... 3/13181804

1x HLG-120H-24AB
https://www.digikey.ca/en/products/deta ... B/10659948

Please let me know if I understand this correctly. I would wire those 5 strips up in parallel. On the driver I would set the voltage to 20.3V. Each strip would use about 960mA, meaning 4.8A in total which is below the driver's rating of 5A. I've heard a bit about thermal runaway, but there should be no concern about it in this type of scenario, right? If one strips gets too hot and starts pulling more current, the driver would quickly hit the 5A limit and start reducing voltages, which would lower the temperature of the overheating strip. Is there anything I'm overlooking?

Went from 2x Bridgelux 50w COBs to a single 48w 96 diode R spec samsung sundaddy strip. IR + far red/deep red.
20 days later:
1x 120mm pc fan, 2x 200mm fans on top for exhaust, powered by a 12v battery. Lined with recycled pieces of grow tent, heatsink cut out of an old Gull wing reflector. Proof of concept more than anything else and for the lulz