LT lurker here, want to pick your brains for specific answer without the trolls and grief? :)

[Sliranax]

Here is what i've purchased

Meanwell HLG-185H-54B
CLU056-1825C1-40AL7G4 X 2

I think I made a mistake because the min current rating for this led is 2250 ma my research leads me to believe that a circuit cannot start with less than the min current rating is that correct? If so i'll order another driver etc. What I cannot seem to grasp is how hot at the max current of the driver - 3450 ma is a pot going to get just wired in series with the cobs? If its manageable i'll go that route but my buddy who's much more electronically educated than I am told me to use a PWMcircuit because a pot would eventually meltdown basically? Idk, I simply do not know enough about math and the electronics to figure it out on my own, so after that in short.

Do you need the min current of a cob to make it turn on as i'm thinking?
And is it feasible at close to the max current of my driver say? 3200ma to use simply a pot or should I do the research and employ a PWMcircuit, which I actually happen to notice Meanwell makes a DALIto PWM converter the.. Dap-04, is all that even necessary though?

Thank you in advance for your time & effort

 

[CanadianONE]

Here is what i've purchased

Meanwell HLG-185H-54B
CLU056-1825C1-40AL7G4 X 2

I think I made a mistake because the min current rating for this led is 2250 ma my research leads me to believe that a circuit cannot start with less than the min current rating is that correct? If so i'll order another driver etc. What I cannot seem to grasp is how hot at the max current of the driver - 3450 ma is a pot going to get just wired in series with the cobs? If its manageable i'll go that route but my buddy who's much more electronically educated than I am told me to use a PWMcircuit because a pot would eventually meltdown basically? Idk, I simply do not know enough about math and the electronics to figure it out on my own, so after that in short.

Do you need the min current of a cob to make it turn on as i'm thinking?
And is it feasible at close to the max current of my driver say? 3200ma to use simply a pot or should I do the research and employ a PWMcircuit, which I actually happen to notice Meanwell makes a DALIto PWM converter the.. Dap-04, is all that even necessary though?

Thank you in advance for your time & effort

2250ma is the nominal current not the minimum. I had a look at the datasheet and those LED's have a 125ma minimum.

 

[CanadianONE]

Here is what i've purchased

Meanwell HLG-185H-54B
CLU056-1825C1-40AL7G4 X 2

I think I made a mistake because the min current rating for this led is 2250 ma my research leads me to believe that a circuit cannot start with less than the min current rating is that correct? If so i'll order another driver etc. What I cannot seem to grasp is how hot at the max current of the driver - 3450 ma is a pot going to get just wired in series with the cobs? If its manageable i'll go that route but my buddy who's much more electronically educated than I am told me to use a PWMcircuit because a pot would eventually meltdown basically? Idk, I simply do not know enough about math and the electronics to figure it out on my own, so after that in short.

Do you need the min current of a cob to make it turn on as i'm thinking?
And is it feasible at close to the max current of my driver say? 3200ma to use simply a pot or should I do the research and employ a PWMcircuit, which I actually happen to notice Meanwell makes a DALIto PWM converter the.. Dap-04, is all that even necessary though?

Thank you in advance for your time & effort

You will not be able to run this driver at 3450ma because it has a maximum output of 54v and that led will draw roughly 56-58v so it will never hit 3450ma because there isn't enough voltage to support it. You should however be able to run 2000-2500ma

 

[DocCox]

Yes, the driver is not a good pairing with the LED as stated. These citizen COBs look to be built to run hard, and don't have major gains from running soft. Find a driver with a couple more V and you will be golden. Find a dimmable driver and you can put the POT or just a resistor on those leads - no need for pwm. I don't think I've seen any melted POTs, the dim+ and - are hardly putting anything out.

On a side note: I've been looking for the larger V4 COBs from citizen and am having a hard time finding them. Can you share where you nabbed them from and what the costs were?

 

[Sliranax]

You will not be able to run this driver at 3450ma because it has a maximum output of 54v?

I dont understand, the datasheet Im looking at says min 47.8v, typ 52.0 and max 56.2, and perhaps this goes back to my lack of any practical experience but how and why would it pull 56-58 as you say? That drivers specs also tell me it has a maximum output voltage of 54 volts which seems to be within the range of the specs of the cobs, this is why I chose these two. I guess what i'm asking Canadian is are you speaking from experience? I guess what I want to say is I need to be able to trust what I read. Excellent news on the min current that alone saved me tons of research I may or may not have been able to understand to a point to convince myself it was safe and no i'm not looking to maximize efficiency I just pulled the trigger on these because its the largest cob within my budget. Based upon what i've read here I thought I did a decent job within what I could spend, I wouldve prefered to push them harder. Can you confirm canadain? is it possible to use just a simple pot and this is a dimmable driver Doc HLG-185H-54B

 

[DocCox]

Well, hook it up and see how many mA it's pushing to the COB. The moment your a tiny fraction over the voltage the driver can deliver your amperage will drop until the driver can deliver. If everything runs perfect you might be A-ok.

 

[DocCox]

Sorry: yes the B at the end of a mean well driver means it's setup for external dimming (pot, resistor, or pwm). The A versions have a built in dimmer on the driver I think, if that a what you like. You want the driver to have a higher output voltage than the maximum your COB can pull - so that driver is very close but not quite there.

2.2v is a noticeable difference. Citizen LED s are uncommon so I'd like to hear more about how it performs. It may just be your chips use the low end of the spectrum and your fine to use that driver.

 

[Rahz]

Look at the cob datasheet and check out the current -vs- voltage chart. That will give you a good idea of what current you can get out of the driver. At 3000ma it want's about 55 volts. The driver will drop the current to limit the voltage. It's possible the driver won't be able to supply 3.45 amps.

The B series drivers have separate wires for connecting the pot. Scroll down to page 2 on the driver datasheet for a diagram of the driver to help identify which wires the pot connects to.

 

[Sliranax]

And this is why i've hesitated so long to ask questions, I know I cannot run the driver wide-open, you did mention something interesting I didn't realise it was a trade-off between voltage and current, yes I fully understand how to connect a potentiometer to this driver its quite self explanatory, what I need to know is it going to burn the pot and or driver up? That's all i'm asking....

 

[CanadianONE]

And this is why i've hesitated so long to ask questions, I know I cannot run the driver wide-open, you did mention something interesting I didn't realise it was a trade-off between voltage and current, yes I fully understand how to connect a potentiometer to this driver its quite self explanatory, what I need to know is it going to burn the pot and or driver up? That's all i'm asking....

A normal 1/4 watt potentiometer will be more then enough without any issues at all. The potentiometer doesn't have to sink very much current at all on the dim + and dim - wires. The current being supplied to the LED's is not going through the potentiometer. Current and Voltage have a direct relationship, the more current you push the more voltage you need. The numbers you keep stating from the datasheet are just the typical numbers. So the min, typ & max are all based on running @ 2250ma not more not less.

 

[Rahz]

Lol, you mentioned running the pot in series with the cobs... and at max current. Then you asked whether or not the driver is dimmable... but you fully understand how to wire it...

And this is why i've hesitated so long to ask questions, I know I cannot run the driver wide-open, you did mention something interesting I didn't realise it was a trade-off between voltage and current, yes I fully understand how to connect a potentiometer to this driver its quite self explanatory, what I need to know is it going to burn the pot and or driver up? That's all i'm asking....

 

[Sliranax]

Well I was assuming the dim leads were in series with the power circuit, wouldn't have guessed they were seperate all together does that mean that a PWM is built into the meanwell power supply? appreciate that canadian that was the answer I was looking for I still find it odd though, why when theres a better option would I want to use a pot over the much more efficient pwm circuit? Other than cost prohibitive reasons. And no I didn't ask if it were dimmable Hmm, I'm feeling like i'm going to need more of a driver, this brings up another question if I plug this psu in the wall and check the leads with a meter the readings will be different than when I have the cobs wired in series on the psu correct? Since from my understanding all circuits are simply resistive to the flow of electricity, so in order to get a correct reading i'm going to have to endanger my cobs?

 

[CanadianONE]

Well I was assuming the dim leads were in series with the power circuit, wouldn't have guessed they were seperate all together does that mean that a PWM is built into the meanwell power supply? appreciate that canadian that was the answer I was looking for I still find it odd though, why when theres a better option would I want to use a pot over the much more efficient pwm circuit? Other than cost prohibitive reasons. And no I didn't ask if it were dimmable Hmm, I'm feeling like i'm going to need more of a driver, this brings up another question if I plug this psu in the wall and check the leads with a meter the readings will be different than when I have the cobs wired in series on the psu correct? Since from my understanding all circuits are simply resistive to the flow of electricity, so in order to get a correct reading i'm going to have to endanger my cobs?

Do not plug this driver in without a load attached to it. I suggest you go back to the datasheet and read from front to back because many of these questions you ask will be outlined in the driver's datasheet. Then after that if you still have questions come back and post and someone will gladly answer them.

 

[Sliranax]

You are assuming I have any understanding to be able to draw a conclusion from a table of data, and you are wrong lol, i've poured over the datasheets for both of these for days before deciding and somehow I still managed to miss the 125ma being the minimum current required to make the cob turn on, I feel like if the pot will work as youve stated and I feel safe that it will, then how am I going to know what i'm getting without endangering my cobs?

 

[CanadianONE]

You are assuming I have any understanding to be able to draw a conclusion from a table of data, and you are wrong lol, i've poured over the datasheets for both of these for days before deciding and somehow I still managed to miss the 125ma being the minimum current required to make the cob turn on, I feel like if the pot will work as youve stated and I feel safe that it will, then how am I going to know what i'm getting without endangering my cobs?

Your COB's can handle more current then your driver can supply. There is no risk of damaging your COB's but it is my understanding that an LED driver should never be switched on without a load. As far as the potentiometer goes it will work no issues there. I believe most diy builds are using the potentiometer method rather then PWM or 0-10v PSU.

 

[Sliranax]

Agreed those cobs can definately handle more than my driver can supply, it was the largest driver the distributor I found had in stock without having to wait 2 months for one to ship from china etc. Not switching the driver on without a load I would not have guessed so that was certainly useful information I appreciate that. And the pot dimming solution I agree seems to be the most popular just didn't want to use it if the only reason it was more popular was cost. So yeah, when my cobs arrive i'll be wiring them up in series, and then testing for voltage and current and watching to see where the sweet spot is, so basically i'm wanting to keep turning it up until my voltage tries to fall out of range? Keeping the voltage in range and just using as much current as my driver can push with that voltage, I looked at the voltage vs current chart again and yeah I can read it, but theres a huge gap between 2000ma and 4000ma kinda hard to guesstimate a reading on that chart. i'm assuming from the data-sheet a 100k pot will work

 

[CanadianONE]

Agreed those cobs can definately handle more than my driver can supply, it was the largest driver the distributor I found had in stock without having to wait 2 months for one to ship from china etc. Not switching the driver on without a load I would not have guessed so that was certainly useful information I appreciate that. And the pot dimming solution I agree seems to be the most popular just didn't want to use it if the only reason it was more popular was cost. So yeah, when my cobs arrive i'll be wiring them up in series, and then testing for voltage and current and watching to see where the sweet spot is, so basically i'm wanting to keep turning it up until my voltage tries to fall out of range? Keeping the voltage in range and just using as much current as my driver can push with that voltage, I looked at the voltage vs current chart again and yeah I can read it, but theres a huge gap between 2000ma and 4000ma kinda hard to guesstimate a reading on that chart. i'm assuming from the data-sheet a 100k pot will work

You plan to run more then one COB in series from this driver?

 

[Sliranax]

Correct I have two of the CLU056-1825C1-40AL7G4 on order, something else i'm grappling with now is i'm looking at this diagram in the datasheet for my driver and I can't figure out why I need a switch and a relay wired on one lead of the ac side of the driver in order to turn it on and off, is it not possible to have a simple mechanical switch to turn this thing on/off as I choose? And if in fact I need both, well theres about a billion different relays on the market? Theres something fundamental i'm not understanding here

 

[CanadianONE]

Correct I have two of the CLU056-1825C1-40AL7G4 on order, something else i'm grappling with now is i'm looking at this diagram in the datasheet for my driver and I can't figure out why I need a switch and a relay wired on one lead of the ac side of the driver in order to turn it on and off, is it not possible to have a simple mechanical switch to turn this thing on/off as I choose? And if in fact I need both, well theres about a billion different relays on the market? Theres something fundamental i'm not understanding here

You will not be able to run two of these in series off this driver. When you wire COB's in series the voltage adds up and the current stays the same. Just as an example each COB requires 45v @ 2A you would need a driver that could supply minimum 90V @ 2A. You can plug the driver into a timer or connect with any switch on the AC side to swith it on and off. The diagram that shows the relay is if you want to be able to dim the light until it shut completely off.

 

[Sliranax]

Hmm, well that's unfortunate after you asked that I was actually wondering if it would halve the voltage or double it I knew something had to be wrong in my thinking for you to ask that. And i've read that you shouldn't wire them in parallel which would? do exactly the opposite? halve the voltage and double the current?