Dimming Mean Well drivers for Dummies (ie. me)

[Rabbitlicker]

I hereby fully admit that I'm absolutely clueless when it comes to this sort of stuff, so I'm seeking some input/knowledge from the cognoscente. I've done some research, but reading the technical stuff does my head-in.

I have a Mean Well HLG-480H-54A driver that powers the LED array in my flowering tent, but I want to be able to dim it & not fry the plants (as happened in my last grow).

The Driver has two potentiometers built-in (Io & Vo), which I can adjust, but my question is WHICH ONE?

Do I need to dial-back the CURRENT, or the VOLTAGE????

I know this is going to seem like a fucking stupid newbie question to some of you, but this is where I'm at right now.

Please be gentle with me & use VERY BASIC language (ie. no jargon or acronyms) that even I can understand.

 

[Goonie Goat]

Get a kill-o-watt meter to plug the light into.

Select the voltage option then take your VO plug out, the light specs should say whether it's 48v, 42v, 24v etc.

Dial it to that number on the killowatt (if that makes sense), then you can plug vo up and leave it.

Then just dim with I/o, the amps or watts should show on the meter if it's that necessary but that's just how I do mine,

If doing it by eye just crank the Io and vo to full blast and dial the vo back until it dims and then dial forward a bit if that makes sense

 

[Rabbitlicker]

Get a kill-o-watt meter to plug the light into.

Select the voltage option then take your VO plug out, the light specs should say whether it's 48v, 42v, 24v etc.

Dial it to that number on the killowatt (if that makes sense), then you can plug vo up and leave it.

Then just dim with I/o, the amps or watts should show on the meter if it's that necessary but that's just how I do mine,

If doing it by eye just crank the Io and vo to full blast and dial the vo back until it dims and then dial forward a bit if that makes sense

How did I know you would be the first to respond to this?? I should've just PM'd you in the first place!!

You have just successfully achieved fucking with my head!!

OK, please, let's get this as simple as possible so I can understand (since I'm a complete plonker when it comes to this stuff). I'm not stupid, just ignorant when it comes to the technical stuff in regards to lights.

For this reason, I deliberately bought a plug & play light array, rather than build my own.

The Mean Well Driver is this one:

https://www.meanwell-web.com/en-gb/ac-dc-single-output-led-driver-mix-mode-cv-cc-with-hlg--480h--54a.

That tells me it's 480W & 54V. Type-A (which is dimmable/adjustable).

In order to dim it via the in-built potentiometers (Io & Vo) with a small screwdriver, which one do I need to fiddle-with? Io or Vo?

Please keep it KISS for me!

Lighting technicals just sucks me into a vortex of WTF!?!?!?!?!?!?

 

[Goonie Goat]

How did I know you would be the first to respond to this?? I should've just PM'd you in the first place!!

You have just successfully achieved fucking with my head!!

OK, please, let's get this as simple as possible so I can understand (since I'm a complete plonker when it comes to this stuff). I'm not stupid, just ignorant when it comes to the technical stuff in regards to lights.

For this reason, I deliberately bought a plug & play light array, rather than build my own.

The Mean Well Driver is this one:

https://www.meanwell-web.com/en-gb/ac-dc-single-output-led-driver-mix-mode-cv-cc-with-hlg--480h--54a.

That tells me it's 480W & 54V. Type-A (which is dimmable/adjustable).

In order to dim it via the in-built potentiometers (Io & Vo) with a small screwdriver, which one do I need to fiddle-with? Io or Vo?

Please keep it KISS for me!

Lighting technicals just sucks me into a vortex of WTF!?!?!?!?!?!?

What kind of light is it?
This might help

Think your driver is more suited to constant current setups.

Each of my led strips pull 37 volts, but my driver can dish out 42 volts or probably more. That's basically why I set the voltage to 37v and just mess with the current i/o screw instead.

It gets to a point where my lights brightness tops out, but I can still dial VO a quarter or so of a turn more, which is just basically wasting more power, creating more heat for no gain at all.. I guess there's no right or wrong answer here, for me it's just finding the sweet spot on the voltage dial, leaving it, and dimming with IO. At this point I couldn't care less about it though so I just pump both dials to the maximum

 

[VinDeezle]

The boards PCB layout is the deciding factor when it comes to voltage (diodes in series X diode forward voltage). Think of the voltage potentiometer as a voltage offset. If the potentiometer is in the middle of its range, the driver will output the boards voltage dictated by the amount of diodes in series. Dialling that voltage potentiometer will apply an offset to the voltage in either direction so it's the current load (lo) you will want to use when dimming.

My meanwell elg-240 48a will run between 42-51v (roughly) with the Vo potentiometer dialled up or down. Pretty sure your Vo offset range is 46-57v if the PCB input is 54v.

Your driver's constant current range is between 27-54v and it's load adjustment is from 4.4a to 8.9a. meaning at 27v PCB voltage, the driver will output 120w-240w, at 36v it will output 160-320w and at 54v it will output 240-480w with the Lo potentiometer adjustments.

 

[VinDeezle]

TLDR, just adjust the current load (lo) not the Vo. Just leave that in the middle as it's an offset to PCB voltage.

 

[HomeBound_Hound]

TLDR, just adjust the current load (lo) not the Vo. Just leave that in the middle as it's an offset to PCB voltage.

TLDR representative here haha

 

[VinDeezle]

TLDR representative here haha

I get a bit ahead of myself sometimes.

 

[HomeBound_Hound]

I get a bit ahead of myself sometimes.

Nah I just ment I very often write out long ass replies that r definitely TLDR worthy hence TLDR representative

 

[Rabbitlicker]

TLDR, just adjust the current load (lo) not the Vo. Just leave that in the middle as it's an offset to PCB voltage.

Thanks for the simple answer. I just had a fiddle with the two potentiometers to see where they were "factory-set".

The Io was already set to "Max" (ie. fully clockwise) & the Vo was set just a crack back from "Max". Maybe 1/8th of a turn. The printing on the two LED boards says "Maximum Board Rating: 48V @ 5A". Since the driver is 54V, I guess this is why the Vo was dialled-back a crack?

I plugged the driver into a basic power meter & it was only pulling 2.1A from the wall, so I'm guessing I'm fine there?

If my understanding of your advice is correct (please confirm if I'm wrong!), in order to dim the lights' intensity, I need to adjust BOTH potentiometers & not just one (ie. Io):

The Vo should be set to 1/2 of its available range & then adjust the light intensity by dialling-back the Io?

What would happen if I was to leave the Vo where it was factory-set & ONLY adjust light intensity with the Io potentiometer? Any problems with that? My own research tells me that drivers work most efficiently when pushed/cranked-up?

Again, apologies for what may seem like "bleedin' obvious" to folks that understand this stuff. I just & simply don't. Hence my questions & why I bought a "plug & play" unit in the first place.

I know my weaknesses about this stuff..

Thanks for your help.

 

[HomeBound_Hound]

Thanks for the simple answer. I just had a fiddle with the two potentiometers to see where they were "factory-set".

The Io was already set to "Max" (ie. fully clockwise) & the Vo was set just a crack back from "Max". Maybe 1/8th of a turn. The printing on the two LED boards says "Maximum Board Rating: 48V @ 5A". Since the driver is 54V, I guess this is why the Vo was dialled-back a crack?

I plugged the driver into a basic power meter & it was only pulling 2.1A from the wall, so I'm guessing I'm fine there?

If my understanding of your advice is correct (please confirm if I'm wrong!), in order to dim the lights' intensity, I need to adjust BOTH potentiometers & not just one (ie. Io):

The Vo should be set to 1/2 of its available range & then adjust the light intensity by dialling-back the Io?

What would happen if I was to leave the Vo where it was factory-set & ONLY adjust light intensity with the Io potentiometer? Any problems with that? My own research tells me that drivers work most efficiently when pushed/cranked-up?

Again, apologies for what may seem like "bleedin' obvious" to folks that understand this stuff. I just & simply don't. Hence my questions & why I bought a "plug & play" unit in the first place.

I know my weaknesses about this stuff..

Thanks for your help.

Only 1 way to learn brother

 

[VinDeezle]

You won't need to touch the Vo potentiometer at all to just dim the current load.

If your boards are 48v, they'll be running at 48v on your driver end as well, not 54v. The Vo potentiometer will just add an offset to that 48v. The 54v of the driver is it's max constant current voltage (it can run anything from 27-54v at 4.4-8.9a via Lo potentiometer, and that 27-54v is decided by the boards diode count in series, not the Vo potentiometer if that makes sense). At 48v you'll be putting out 4.4a (211w) with the Lo at min and 8.9a (422w). Hence why they have close to a full positive offset on the Vo to push the output over 420w.

In constant current mode the driver will always output 4.4-8.9a (via the inbuilt potentiometer) at whatever voltage the boards are running at. The Vo potentiometer will just add a small + or - offset to the boards voltage.

Sorry if I get a bit complicated.

 

[Rabbitlicker]

Only 1 way to learn brother

I've tried doing my own research on this, but I don't honestly understand what I've read. That's why I'm asking questions of people that do understand. I don't think that's unreasonable.

I REALLY don't want to "have a go" & blow-up a light/driver that I shelled-out over $1000 for & potentially burn down my shed, when I can get some good & simple advice from people willing to guide me through my acknowledged ignorance.

Analogy: "Here's a parachute, the aircraft is warming-up over there. Never jumped before? No worries mate! Just have a go! Only 1 way to learn........".

 

[SAW]

You’re doing ok Bunny licker. I could understand their answers if I applied myself, but could understand you perfectly so I think you’re on track

 

[VinDeezle]

I've tried doing my own research on this, but I don't honestly understand what I've read. That's why I'm asking questions of people that do understand. I don't think that's unreasonable.

I REALLY don't want to "have a go" & blow-up a light/driver that I shelled-out over $1000 for & potentially burn down my shed, when I can get some good & simple advice from people willing to guide me through my acknowledged ignorance.

Analogy: "Here's a parachute, the aircraft is warming-up over there. Never jumped before? No worries mate! Just have a go! Only 1 way to learn........".

Luckily nothing's going to explode, and there's nothing wrong with being cautious. Turning any of those potentiometers to any extreme will not do anything that will cause any safety risks. The voltage offset the driver will apply is still within voltage tolerance of the diodes in your case.

The Vo potentiometer adds a small offset to the board voltage and the Lo potentiometer regulates the voltage output multiplied by 4.4 at its minimum and 8.9 at its maximum.

 

[VinDeezle]

So with your current setup, dialing everything to max accidentally is not a real safety issue. However, dialing the Vo all the way down will run a forward voltage for each diode a bit low. The Lo is all you'll need to dim the lights.

 

[HomeBound_Hound]

I've tried doing my own research on this, but I don't honestly understand what I've read. That's why I'm asking questions of people that do understand. I don't think that's unreasonable.

I REALLY don't want to "have a go" & blow-up a light/driver that I shelled-out over $1000 for & potentially burn down my shed, when I can get some good & simple advice from people willing to guide me through my acknowledged ignorance.

Analogy: "Here's a parachute, the aircraft is warming-up over there. Never jumped before? No worries mate! Just have a go! Only 1 way to learn........".

Yeah but how did ya learn to ride a bike... jist saying eventually even after research ya still have to get ya toes wet... and if ya jumped on ya own I bet u wouldn't forget where ya rip cord is lmfao

 

[Rabbitlicker]

Thanks for everyone's input here & allowing me to get this stuff cemented in my own head (even 'though it's been like trying to understand a fucking cricket or AFL score with all the numbers & terminology!!).

Yeah but how did ya learn to ride a bike... jist saying eventually even after research ya still have to get ya toes wet... and if ya jumped on ya own I bet u wouldn't forget where ya rip cord is lmfao

Dear Sir/Madam,

FYI, I've jumped many times. From balloons, helicopters, small/medium aircraft, Caribou's & C-130's.

Multiple times, at night from less than 500ft with more than my own body-weight attached, carrying a shitload of radio gear & a loaded weapon.

I've also skydived naked from 15000ft. I kid you not. I've got it on video somewhere.

I am not without experience.... Hence the analogy I used.

I also fully acknowledge/understand where my ignorance needs help & guidance from people more knowledgeable on a particular subject & seek their input until it sinks-in.

Hey! Could I interest you in an evening of unbridled passion & whipped-cream fights??

 

[HomeBound_Hound]

Thanks for everyone's input here & allowing me to get this stuff cemented in my own head (even 'though it's been like trying to understand a fucking cricket or AFL score with all the numbers & terminology!!).


Dear Sir/Madam,

FYI, I've jumped many times. From balloons, helicopters, small/medium aircraft, Caribou's & C-130's.

Multiple times, at night from less than 500ft with more than my own body-weight attached, carrying a shitload of radio gear & a loaded weapon.

I've also skydived naked from 15000ft. I kid you not. I've got it on video somewhere.

I am not without experience.... Hence the analogy I used.

I also fully acknowledge/understand where my ignorance needs help & guidance from people more knowledgeable on a particular subject & seek their input until it sinks-in.

Hey! Could I interest you in an evening of unbridled passion & whipped-cream fights??

Yeah I think you've stated that before haha hey more power to ya sounds amazing but just food for thought someone had to be the first

As for the evening ya barking up the wrong tree there bud

 

[HomeBound_Hound]

The original comment was never ment to offend just FYI