Current will ALWAYS be regulated by varying the output voltage

GrowLightResearch said:
Why would you do that? Do you not care how much current is flowing?
Click to expand...
Why would I do that? IT WAS A TEST! No, I was not concerned with the current level, IT WAS A TEST!

In the other thread you said "With a max current output of 16.7 Amps that will smoke a Citi 1212 in a millisecond if connected with out the HLG being current limited."

I just proved that operating at 37.8 volts constant voltage WILL NOT smoke a citi 1212 in a millisecond without being current limited!
 
1212ham said:
just proved that operating at 37.8 volts constant voltage WILL NOT smoke a citi 1212 in a millisecond without being current limited!
Click to expand...

All I knew about the CoB is it was a Citi 1212. But that did not matter, I presumed that the proper diver was chosen for which ever 1212 Vf. I did not realize that you guys did not know how to choose the proper driver.

For a CLU048-1212C4 the driver should have been a 42v HLG.

So why do you use a 36v HLG for a CoB with this Vf curve? A 36v diver is about 4v short.
This is obviously a job for a 42vn HLG. Or with a max Vf @ 1080 & 25°C of 37.5v?

Untitled.jpg


BTW the post was about running the CoB at 1800mA. The burn was a tangent. And if the proper driver was being used "likely it would burn".
 
GrowLightResearch said:
All I knew about the CoB is it was a Citi 1212. But that did not matter, I presumed that the proper diver was chosen for which ever 1212 Vf. I did not realize that you guys did not know how to choose the proper driver.

For a CLU048-1212C4 the driver should have been a 42v HLG.

So why do you use a 36v HLG for a CoB with this Vf curve? A 36v diver is about 4v short.
This is obviously a job for a 42vn HLG. Or with a max Vf @ 1080 & 25°C of 37.5v?

View attachment 4073187


BTW the post was about running the CoB at 1800mA. The burn was a tangent. And if the proper driver was being used "likely it would burn".
Click to expand...
The reason I had even mentioned the 1800ma was just hypothetical because someone a few pages back was insinuation that a CC driver can not over power a led. And when I say "power" I am referencing watts. I thought CC drivers could overpower leds hence the whole reason most people advise against parallel wiring because if something happens to one COB or led than the others will have to share the additional load.
 
GrowLightResearch said:
All I knew about the CoB is it was a Citi 1212. But that did not matter, I presumed that the proper diver was chosen for which ever 1212 Vf. I did not realize that you guys did not know how to choose the proper driver.

For a CLU048-1212C4 the driver should have been a 42v HLG.

So why do you use a 36v HLG for a CoB with this Vf curve? A 36v diver is about 4v short.
This is obviously a job for a 42vn HLG. Or with a max Vf @ 1080 & 25°C of 37.5v?

View attachment 4073187


BTW the post was about running the CoB at 1800mA. The burn was a tangent. And if the proper driver was being used "likely it would burn".
Click to expand...

Absolutely nothing wrong with using the HLG-600H-36B to drive a bunch of citizen 1212s in parallel. The driver will limit the voltage to around 36 - 38 volts and the cobs will run just fine without risk of runaway. The current will be around 1800 to 2000 ma.
 
GrowLightResearch said:
All I knew about the CoB is it was a Citi 1212. But that did not matter, I presumed ....
"likely it would burn".
Click to expand...
Good spin, spoken like a true politician.

You stated "With a max current output of 16.7 Amps that will smoke a Citi 1212 in a millisecond if connected with out the HLG being current limited."

Now you say "All I knew", "I presummed", "likely it would burn"
 
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GrowLightResearch said:
So why do you use a 36v HLG for a CoB with this Vf curve? A 36v diver is about 4v short.
.
Click to expand...
I didn't say I use a 36v HLG. While a 36v driver will not push a 1212 gen5 to it's absolute maximum current, most run them close to nominal current.
If you want to assert that's improper, I don't give a damn. I'm done with you. Rather than presuming things, I have actual hands on experience and read the datasheets!
 
nxsov180db said:
Just curious as to which driver you used?
Click to expand...
With no doubt the 42v. Just by looking at the graph in my previous post it is obvious the 36v is inadequate to operate the CoB over its full range.

Taking into consideration these number are for 1080mA @ Tj= 85° C. Other numbers in the datasheet are specified at Tcase= 25° C (e.g. the graph in my previous post).

Untitled.jpg

The way to choose the driver is to fit the min-max into the range of constant current operation as shown above.
Except you wanted 1800mA. These values are for 1080mA. You would use the graph in my previous post to find the typical Vf @ 1800mA then add and subtract 3v for max and min values.

All the min-max values for this CoB fit better in the 42v driver's 21-42v range. They do not fit in the 18-36v range of the 36v.

Untitled2.jpg

Your wattage is way too high. A 600 watt driver is not very efficient for a single CoB.

I have attached a PDF. I do not expect you to fully understand. You may pick up some things. If you have any questions I can explain anything in this document.

Section 1,2, and 5 are applicable.

Section 1 backs what I have been saying. The CoB is an InGaN LED. The sense resistor is internal to the HLG and is how the current is monitored.

In section 2 a HLG is a Buck Driver. This explains why the 42v is a better pick than the 36v.

Section 5 is about the complexities of Vf.
 

Attachments

PurpleBuz said:
Absolutely nothing wrong with using the HLG-600H-36B to drive a bunch of citizen 1212s in parallel.
Click to expand...
:roll:

The min to max Vf of this CoB fits much better in the 42v HLG. the 36v is not the correct selection for this CoB.

Do as you please. Just letting you know the 42v is a much better choice. Do with that tidbit as you please.

Absolutely nothing is taking it a bit too far. The 36v does not operate within the full capabilities of the CoB. The 42v does. If you'd rather be a cripple, be a cripple.
 
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nxsov180db said:
The reason I had even mentioned the 1800ma was just hypothetical because someone a few pages back was insinuation that a CC driver can not over power a led.
Click to expand...

A driver should be able to operate over the full operating characteristics of the CoB. This usually means the driver can over power and burn the CoB. The datasheets are only typical values. Getting the values for yuor specific application is not a trivial task. You must consider how the current and temperature affect the forward voltage.

For example this CoB's datasheet gives the min and max only at 1080mA. You have to use the other characteristics to calculate the value for your application.

I should tell you CoBs are no longer a good option for a DIY grow light. But I will not, otherwise the CoB snobs will attack.

You must consider how many µmols of photons you want to reach your plant. Then you need to select the optimal distance between the canopy and grow light. This requires selecting the µmols at the canopy top and the µmols desired inside the canopy. I suggest 1000-1500 µmols.m²/s at the canopy top and at least 500 half way through the canopy. This can economically be done with LED strips. It cannot be accomplish very well with CoBs due to their lack of uniformity.
 
The Dawg said:
Come On Guys Dont You Recognize Who This Is?? When We Pull The Curtain Back GrowLightResearch Is Non Other Than NoFucksToGive
Click to expand...
Little late to the party. That was never a secret. But guess what? I still have no fucks to give. Some how I always thought you were old enough to understand me. But no, you don't get it. You seem too grouchy. Still I like how you do things here. You know what you are doing. Many others here do not. I especially liked your experiments with the Décor 1750K.
 
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1212ham said:
Now you say "All I knew", "I presummed", "likely it would burn"
Click to expand...
I started with "likely" it would burn.
Carefully chosen because I did not have all the necessary information. Now it's should have burned. It would if the proper driver was chosen. You can use whatever driver you want. I do not care. I'm only saying the 42v is the far superior choice to the 36v. Take it for what YOU think it is worth. I do not care. I'm just the messenger.
:blsmoke:
 
So an HLG-600H-42B Connected to 1 citi1212 undimmed would blow the cob from too much current? No I do not want to run single COB off of a 600 watt driver it is a hypothetical question from a member a few pages back on cobkits thread whom made it seem as though it is not possible to supply an led/cob with too much current from a MW CC driver.
 
GrowLightResearch said:
I started with "likely" it would burn.
Carefully chosen because I did not have all the necessary information. Now it's should have burned. It would if the proper driver was chosen. You can use whatever driver you want. I do not care. I'm only saying the 42v is the far superior choice to the 36v. Take it for what YOU think it is worth. I do not care. I'm just the messenger.
:blsmoke:
Click to expand...
good god dude you just can't admit that you are wrong
GrowLightResearch said:
:roll:

The min to max Vf of this CoB fits much better in the 42v HLG. the 36v is not the correct selection for this CoB.

Do as you please. Just letting you know the 42v is a much better choice. Do with that tidbit as you please.

Absolutely nothing is taking it a bit too far. The 36v does not operate within the full capabilities of the CoB. The 42v does. If you'd rather be a cripple, be a cripple.
Click to expand...

bullshit
If I choose to run the cobs at around 1800 - 2000 ma in parallel its the perfect combo.
 
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