COB efficiency Spreadsheets

Organic Miner

Well-Known Member
See that's what I don't understand but i get it so basically its a 185 700 with those two strings running at 700ma
Well, this only true because you are basically using "identical" cobs for both paths. The voltage across each path is identical, but the current through each path may vary depending on the threshold voltage of each cob in each path (not to go all gweaky on you). The total current must 1400 mA, but it maybe 750 in one path and 650 in the other. You will notice this if one set of cobs is brighter than the other. This because thresholds are not linear and may vary cob to cob. Hope this didn't confuse.
 

TogiX

Active Member
If one were to do two strings of two LED's per string, what type of driver does it have to be? CC, CV, CC+CV?

Asking because there aren't any ~70V driver options for Vero 29 Type C in CC+CV.
 

Organic Miner

Well-Known Member
If one were to do two strings of two LED's per string, what type of driver does it have to be? CC, CV, CC+CV?

Asking because there aren't any ~70V driver options for Vero 29 Type C in CC+CV.
upload_2017-1-12_17-10-48.png

The HLG-185-1400 can provide 143V across the 2 paths of 2 COBs each, and provide 700mA (2x700mA=1400mA) for each path. The 143V is MAX output, so you will be fine with 2x70v.
 

wietefras

Well-Known Member
I believe it notes the high voltage version. All HLGs are constant current and some of them (A versions) can work as constant voltage as well.
If you take the HLG-185H-C1400A:
The "H" denotes high input voltage. The "C" denotes constant current (with the current in mA next to it).

Drivers without the "C" are constant voltage and have the voltage as the last number. Like HLG-185H-36A for the 36V model.

The A or B (etc) at the end refers to the method of dimming (A for built-in pot and B for "external" dimming).
 

alesh

Well-Known Member
If you take the HLG-185H-C1400A:
The "H" denotes high input voltage. The "C" denotes constant current (with the current in mA next to it).

Drivers without the "C" are constant voltage and have the voltage as the last number. Like HLG-185H-36A for the 36V model.

The A or B (etc) at the end refers to the method of dimming (A for built-in pot and B for "external" dimming).
I was probably wrong about what the letter C meant.
But I'm pretty sure that HLG's w/o C are combined constant current and voltage as well (you can check its data sheet). I'd like to hear how is ie HLG-185H-36B a constant voltage driver. I think it's actually (the B version) CC only. Or is there something I'm missing?
 

wietefras

Well-Known Member
I was probably wrong about what the letter C meant.
But I'm pretty sure that HLG's w/o C are combined constant current and voltage as well (you can check its data sheet). I'd like to hear how is ie HLG-185H-36B a constant voltage driver. I think it's actually (the B version) CC only. Or is there something I'm missing?
The point is that they don't run at a fixed mA value, but at a fixed voltage. In the end it's constant current in the sens that xW at yV together have the same amperage.

That 36B driver runs at 36V. The mA per COB will depend on the number of COBs connected.

Anyway, it's more semantics I guess, but you do connect the HLG-C drivers differently from the ones without the other HLG drivers
 

alesh

Well-Known Member
The point is that they don't run at a fixed mA value, but at a fixed voltage. In the end it's constant current in the sens that xW at yV together have the same amperage.

That 36B driver runs at 36V. The mA per COB will depend on the number of COBs connected.

Anyway, it's more semantics I guess, but you do connect the HLG-C drivers differently from the ones without the other HLG drivers
Now I'm pretty confused.
How can be (ie) HLG-185H-36B a constant voltage source? You can't directly regulate voltage on it I believe. It puts out 5.2A in the 18-36V region. If your load needs 20V to pull 5.2A through the driver will adjust o/p voltage to 20V. You can change set current which will result in driver changing its output voltage to match it. Isn't that what CC sources are supposed to do?
 

ledgardener

Well-Known Member
Now I'm pretty confused.
How can be (ie) HLG-185H-36B a constant voltage source? You can't directly regulate voltage on it I believe. It puts out 5.2A in the 18-36V region. If your load needs 20V to pull 5.2A through the driver will adjust o/p voltage to 20V. You can change set current which will result in driver changing its output voltage to match it. Isn't that what CC sources are supposed to do?
I have not yet played with one of these CV+CC drivers, though I would really like to get one, just to see how they actually work.

According to the data sheet, it operates as a constant voltage driver (and there is a pot to adjust output voltage from 33V-40V on the "A" type, as well as one to adjust the current) up until the point where the load draws the max amount of current, at which point it holds the max current steady in constant current mode. I think the 18-36V constant current region in the data sheet refers to the fact that once you hit the max current ability of the driver, it will only hold it steady between those voltages.

If I understand this correctly, if you configure your driver to output 36V, then hook up 5 COBs that draw 1 Amp each at 36V, you'd still be running in CV mode, and the driver would hold its 36V output and provide 5A of current. If you then added one more COB in parallel, you'd enter CC mode and be left with the max current of 5.2A to distribute among the 6 COBs.

The part I'm trying to figure out is where that 18V figure from the constant current region spec would even come into play, since you can only adjust the voltage down to 33V. My best guess is that if you were to turn down the current all the way to minimum (2.6A), this would become the new point at which the driver switches to CC mode, and voltage adjustment range would then scale down with it as well. Now, maybe the driver would hold 2.6A in constant current mode down to 18V. Would love to hear somebody who has one chime in and clarify, since I've wondered this for awhile.
 
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