F Series driver recommendation

Prawn Connery

Well-Known Member
Application: Pure veg
Room: 2.5'x2'
LED strips: 4x F Series 5000K, 559.70mm L x 39.80mm, SI-B8R521560WW
Driver: ???

I've decided to buy four 2' strips - the equivalent of two QB288 boards - and mount them on some aluminium U channel for my veg chamber. My understanding is these are max 48.4v/1.8a boards that are usually run around 60%, or 46v/1.12a.

https://www.digikey.com.au/product-detail/en/samsung-semiconductor-inc/SI-B8R521560WW/1510-2224-ND/6624008

I'm looking at a Meanwell HLG-240H, but would likely dim them down to about 180-200w total draw, or 46v/1.05a or any combination thereof.

Initial thoughts are to run them 2s 2p with a 2.1a driver for 92v (or thereabouts) total. But I could simply run all four in parallel with a 48v CV driver and dim the amps. Or I could go the other way and run all four in series with a 1.05a CC driver.

What would you suggest and why? I'm also open to the option of running something like a HLG-185H-C1050A with everything in series, but the 240 gives me the option of stepping up things - though I'm not sure how much they can be dimmed. I'm assuming a 240 can be dimmed down to, say 150w total.

I chose the F Series based on cost, coverage, and the fact strips allow you to use a "skeleton" hangar (each 40mm U channel would be spaced about 100mm or 4" apart) for better airflow. Heat maintenance is a primary consideration in my grow chamber. I could go with three strips, but I'd rather run four for the more even coverage and efficiency.

Caveat: I have many years of growing experience, but I have not played with LEDs before, so am not familiar with constant current vs constant voltage pros and cons. I just want something I can play around with as an introduction to LED that is safe, reliable and not too hot. Cheers.
 

nc208

Well-Known Member
The trick to selecting driver for samsung chips is to know they can handle a max current of 200ma per diode. The strip you selected is set up with 16 series and 9 parallel. So whatever Current you choose divide by 9 to see how much your giving to each string.

If your running a 1050 ma driver let's say constant current then you would be driving them at 116.6667 ma per diode. That's the exact same efficiency I drive mine.

Constant voltage you wire in parallel and split the current by how many strings your running.

Or do constant current and add up voltages for each board and pick a 1050 ma cc driver.
 

Prawn Connery

Well-Known Member
I get that bit. I guess what I'm asking is, what are the pros/cons of running, say, a 48v constant voltage driver with the four boards in parallel, or a 1050ma constant current driver with the four boards in series, or a 2100ma constant current driver with two boards in series and two in parallel?

What are the advantages of constant current vs constant voltage and high voltage/low current vs high current/low voltage vs medium current/medium voltage?

For example, there might voltage limits on the wago connectors, or perhaps constant current is more stable or possibly some other reason for me to choose one driver over another that I don't understand.

What would you suggest and why? Thanks.
 

Prawn Connery

Well-Known Member
Strips are on their way. I'm now leaning towards the HLG-185H-C1050A to drive the four strips in series.

Will the HLG-185H be more efficient than the HLG-240H? 180w is enough for my application, but should I get something like the HLG-240H-C1400A and dial down the amperage to leave a bit more power up my sleeve if I need it?

I'm guessing the HLG-240H-C1400A would drive the boards at about 78% (156ma per diode) at 44.75v, which is within spec - have I got those numbers right?

Is it preferable to keep voltage on the low side of specs to reduce heat? As mentioned, heat will be more of an issue in my grow room than overall wattage or efficiency. This will be for a dedicated veg/cloning chamber, so plant maintenance and medium growth is what I'm aiming for.
 

CoB_nUt

Well-Known Member
All great questions Prawn. Hopefully some of the gurus will chime in. I 'd definitely like theto see the responses and answers.
 

nc208

Well-Known Member
Bigger is better. You dim it and it will run softer in the driver vs a smaller driver on full blast.

HLG series are very good. ELG are also good if you want to save a bit of cash. Definitely go with the 240 over the 185. If you want to use a dimmer then get the b version. The A version has screw on bottom. In terms of CC vs CV I don't think it'll make a difference when only running 4 strips. CC or CC + CV will be easier to locate than a cv I found when recently shopping for drivers. Stick with the 1400 ma or look at using a 48v 5 A and wire in parallel for 1250ma per string which works out to 138.8 ma per diode. I maxed mine out at 116.6667 ma because my space is small so if your lighting a bigger area having more power can be handy.
 

nogod_

Well-Known Member
Higher voltage (constant current) is more dangerous although I run all my strings of cobs on constant current drivers at ~280v and I'm still alive.

Constant voltage technically leaves you open to thermal runaway if one of your strips has significantly higher voltage than the others. This causes that one strip to heat up more which in turn causes it to increase voltage more which in turn causes it to draw more and heat up more than the other strips in the circuit. Hence "runaway".

If your cooling is sufficient it is unlikely that thermal runaway will be an issue. You can also crank down the voltage on a cc/cv driver to just over your normal operating voltage to prevent runaway.

TL:DR - I like constant voltage drivers for strip builds.

I get that bit. I guess what I'm asking is, what are the pros/cons of running, say, a 48v constant voltage driver with the four boards in parallel, or a 1050ma constant current driver with the four boards in series, or a 2100ma constant current driver with two boards in series and two in parallel?

What are the advantages of constant current vs constant voltage and high voltage/low current vs high current/low voltage vs medium current/medium voltage?

For example, there might voltage limits on the wago connectors, or perhaps constant current is more stable or possibly some other reason for me to choose one driver over another that I don't understand.

What would you suggest and why? Thanks.
 

RandomHero8913

Well-Known Member
Application: Pure veg
Room: 2.5'x2'
LED strips: 4x F Series 5000K, 559.70mm L x 39.80mm, SI-B8R521560WW
Driver: ???

I've decided to buy four 2' strips - the equivalent of two QB288 boards - and mount them on some aluminium U channel for my veg chamber. My understanding is these are max 48.4v/1.8a boards that are usually run around 60%, or 46v/1.12a.

https://www.digikey.com.au/product-detail/en/samsung-semiconductor-inc/SI-B8R521560WW/1510-2224-ND/6624008

I'm looking at a Meanwell HLG-240H, but would likely dim them down to about 180-200w total draw, or 46v/1.05a or any combination thereof.

Initial thoughts are to run them 2s 2p with a 2.1a driver for 92v (or thereabouts) total. But I could simply run all four in parallel with a 48v CV driver and dim the amps. Or I could go the other way and run all four in series with a 1.05a CC driver.

What would you suggest and why? I'm also open to the option of running something like a HLG-185H-C1050A with everything in series, but the 240 gives me the option of stepping up things - though I'm not sure how much they can be dimmed. I'm assuming a 240 can be dimmed down to, say 150w total.

I chose the F Series based on cost, coverage, and the fact strips allow you to use a "skeleton" hangar (each 40mm U channel would be spaced about 100mm or 4" apart) for better airflow. Heat maintenance is a primary consideration in my grow chamber. I could go with three strips, but I'd rather run four for the more even coverage and efficiency.

Caveat: I have many years of growing experience, but I have not played with LEDs before, so am not familiar with constant current vs constant voltage pros and cons. I just want something I can play around with as an introduction to LED that is safe, reliable and not too hot. Cheers.
My vote is for the Constant Voltage driver. The HLG-185H-48A will power your four strips at just under 1amp per strip. You could bump up to the HLG-240H-48A and have 5amps to play with. So you'll need to turn down the current to get you at your desired running amperage. Also, all of the Constant Voltage drivers allow you to adjust the current so if you need to turn them down for seedlings or veg you can. The 185H can power down to 1.95A running your strips at .4875ma each and the 240H can go down to 2.5A running your strips at .625ma each.

I think the best part of Constant Voltage drivers running strip lights is that it's so easy to just add another strip to your setup without worrying about going over the voltage limit. And for every strip you add you'll gain some efficiency.
 

Rider509

Well-Known Member
LED strips: 4x F Series 5000K, 559.70mm L x 39.80mm, SI-B8R521560WW
Driver: ???

I've decided to buy four 2' strips - the equivalent of two QB288 boards
I'm not saying that you're wrong, but I'm curious as to how you determined that four of those 24" F Series Gen3s is the equivalent of two QB288s? They both use the LH561C LED chip. Four F Series would have 192 leds. Two QB288s would have 576 leds.
 
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nfhiggs

Well-Known Member
I get that bit. I guess what I'm asking is, what are the pros/cons of running, say, a 48v constant voltage driver with the four boards in parallel, or a 1050ma constant current driver with the four boards in series, or a 2100ma constant current driver with two boards in series and two in parallel?

What are the advantages of constant current vs constant voltage and high voltage/low current vs high current/low voltage vs medium current/medium voltage?

For example, there might voltage limits on the wago connectors, or perhaps constant current is more stable or possibly some other reason for me to choose one driver over another that I don't understand.

What would you suggest and why? Thanks.
I prefer running parallel with CV drivers. If you have a problem in one strip it does not affect the others. Wit CC and series, one problem can take all the board offline, then you have to try to figure out which board has the problem.

Other than that there really aren't a lot of pros/cons one way or the other, IMO. Its really just a matter of preference.
 

nfhiggs

Well-Known Member
I'm not saying that you're wrong, but I'm curious as to how you determined that four of the 24" F Series Gen3s is the equivalent of two QB288s? They both use the LH561C LED chip. Four F Series would have 192 leds. Two QB288s would have 576 leds.
The 2" wide double row F-series in 560 mm length have 144 diodes each (16s x 9p). I think you are looking at the single row H series which have 48 diodes each. This is why the F series was so eagerly anticipated when they were announced - 50% higher diode count at a lower price point, plus double row option, which the H series did not offer.
 

Rider509

Well-Known Member
The 2" wide double row F-series in 560 mm length have 144 diodes each (16s x 9p). I think you are looking at the single row H series which have 48 diodes each. This is why the F series was so eagerly anticipated when they were announced - 50% higher diode count at a lower price point, plus double row option, which the H series did not offer.
Ahh, yes, you're right. Those double row F Series kick ass. It makes sense now.
 
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Prawn Connery

Well-Known Member
Thanks for all the replies so far. You guys wouldn't believe the amount of info I've gleaned on these boards over the past few weeks. For an old-skool grower like myself wanting to get back in the game, it's fascinating!

I've been doing a bit more reading, so I think I'm starting to get this . . . but please correct me if I'm wrong!

So I've ruled out running 2s 2p with the 2.1a CC driver because, from what I understand, parallel circuits with constant current drivers are susceptible to thermal runaway. What happens is the current is split between two sets of boards. Without a current mirror or over-current protector, there is the risk one board set will draw more amps than the other. This in turn lowers the voltage, requiring more amp draw. The extra amperage is taken from the other board set, which raises its voltage, requiring less amp draw. Eventually, one board set is hogging the amps and burns out (thermal runaway) and when it does, all the power goes to the other board set, which also burns out. Unless the total amps in the circuit are less than 50% of the maximum amperage of each board, in which case there may still be an imbalance between each parallel board set.

That leaves 4 parallel boards with CV or 4 in series with CC . . .

Running all boards in parallel with a constant voltage driver means one or more boards may still be drawing more amps than the others, but there is no risk of thermal runaway. But it may still create imbalances in each board, as well as individual leds. In addition, as each board heats up, it requires more amps for the same set voltage, and efficiency is lost through the ballast resistors.

(Correct me if I'm wrong, but the spec sheets I've read state forward voltage drops with higher temperature - not the other way around.)

The main advantages to CV that have been pointed out are that you can add boards without exceeding driver voltage, as well as the ability to identify, isolate and/or bypass individual boards if there are problems.

The last point is worth noting: I guess with a CV driver you could test each individual board without exceeding amperage - you can't do that with a CC driver. Or can you (by winding down the amperage)?

I have no experience with these drivers, so I don't know.

What I do know is I'm not planning on adding any more boards to this set-up, nor playing with the output between cycles, as it is purely for vegging/cloning - it will be a dedicated light source - and the 4 boards I've purchased are more than enough for my needs, and will likely need to be driven at about 55-60% for the desired output. That's plenty of room to grow (pun intended!).

That just leaves the constant current driver.

What's the difference between the A and B drivers?

And finally, I've posted a spec sheet link below. On page 21 you can see the relationship between current and voltage. I've worked out that at 1.08a, each board will drop 46v (2.75v/120ma per diode).

http://www.samsung.com/global/business/business-images/led/file/product/lighting/201511/Data_Sheet_LM561C_Rev.3.2.pdf

This seems to be my sweet spot. So my question is, if I had a HLG-240H-1400, and I dialed it down to 1.08a, would the resulting series voltage of 184v exceed the driver maximum output voltage of 179v - or is there a buffer, or should I be conservative and simply run the HLG-240-1050?

EDIT: OK, I think I've answered this one ^. Apparently the HLG-240H-1400 will hold the total voltage at 179v (maximum) and lower the current - which means at its maximum voltage output, it becomes a constant voltage driver. To keep voltage below 179v, I'd need to drive each diode at about 2.8v/75ma (44.8v per board) for total output of 0.675a.

Is this right?
 
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Prawn Connery

Well-Known Member

Prawn Connery

Well-Known Member
I'm hoping Digikey still has some in December when I get my bonus...
Awesome company to deal with so far, I must admit. Placed my order last night and got a text a few hours later saying they were on their way, DHL. Free courier shipping to Australia, too! If they arrive in one piece, I'll be more than happy.
 

3GT

Well-Known Member
That's Mr Connery to you. Or James Pond :bigjoint:

Seriously, thanks mate. But what's the diff between the ELG and HLG? By a process of elimination - and with my limited knowledge - it seems the 240-1050 driver might be most suitable for my application.
Beg my pardon Mr Connery, the difference is $25au ($63 vs $88) and 0.5% efficiency (93% elg vs hlg 93.5%).

A version has an internal potentiometer for dimming via flatblade screwdriver

B version has external dimming leads to connect a pot to? I went B version for all my drivers :) $2 100k ohm pot from jaycar soldered on and you're in business.

I think elg series drivers aren't as popular here since running them on 110v derates the output.. For anyone on 240v you're crazy to go HLG unless youre chasing .5% efficiency? IMO buy 1 more strip for the price difference and you'll probably gain that 0.5% back anyway?
 

3GT

Well-Known Member
Awesome company to deal with so far, I must admit. Placed my order last night and got a text a few hours later saying they were on their way, DHL. Free courier shipping to Australia, too! If they arrive in one piece, I'll be more than happy.
Future buying tip; Try searching arrows website for part numbers before buying at digikey or mouser since they're normally cheaper :D
 

3GT

Well-Known Member
Anyone ever had a coughing fit right after ripping a bong, just before going for a shit that's about to fall out? I just about broke my bowl
 
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