adjustable current driver for Citizen CLL040

Hi,


I have a citizen CLL040 LED that I need to find a suitable driver for. Looking at the data sheet, it seems to use between 50-60V, and current is between 250mA and 2160mA. I could either get an AC/DC driver, or a DC/DC driver accompanied by a AC/DC power supply. For starters I'd like to be able to adjust the current with a simple turn knob, though later it would be cool to control the LED intensity via an arduino or something similar.


Practically, I simply need to know the correct terminology and good places to look to find a pre-made unit to drive this LED, or if it's not too complicated, how to put together a driver myself.


First off, I'm a bit confused by terminology; if I want to find a pre-manufactured unit for this, should I be looking for a 'variable current led driver' or a 'boost up converter' or a 'buck converter' or something else?? What specs and terminology should I be using to find what I'm looking for on the web? I have seen several buck converters that say adjustable, vs continuous adjustable, what's the difference? Also, I've seen units that say they're both voltage and current adjustable; it's not possible to specify both at the same time is it? My understanding is that you can set one (V or A), but then the converter gets to adjust the other to maintain what you asked for.


Most of the led drivers I see on the web, in web stores, etc aren't rated for such high voltage, and when I search for 'led driver' on the big electronic parts stores, such as digikey, the search results seem to be mostly IC chips that an electronics engineer can incorporate into their projects, and I get dizzy looking at the datasheets on these things


How complicated would it be to put together my own driver? Could i use one of these IC chips that's specifically designed for driving LEDs? I only have beginning knowledge with circuits but do enjoy DIY projects!

" it seems to use between 50-60V, and current is between 250mA and 2160mA."
- that's a challenging voltage range. I don't know of any that go that high, whereas you can get ones for $18 to drive 32 volt LEDs. I'd be changing LEDs.

" 'variable current led driver' or a 'boost up converter' or a 'buck converter'"
- You need a constant-current or current-limited supply. Boost means the DC output voltage must always be higher than the input. Buck is the opposite.

" I've seen units that say they're both voltage and current adjustable; it's not possible to specify both at the same time is it? My understanding is that you can set one (V or A), but then the converter gets to adjust the other to maintain what you asked for."
- Supplies can set the MAXIMUM voltage or the MAXIMUM current. When you reach one limit the LOAD will determine how the other changes e.g. if you reach the current limit, the load will determine what the voltage across the load will be at that current.

If you really want to build something yourself, I would suggest starting with an existing supply designed for a higher voltage and modifying it to deliver a lower voltage and setable current limit.

There are a number of drivers out there that will fit the bill. Thomas Research, Inventronics, and a few others have 150W drivers that will output the current and voltage that you would need for this LED. I warn you though, they aren't cheap

If you list the specific model number of the LED, we can help narrow down your selection, as I'm sure you don't need a 10v swing in voltage.

Building a driver is a little tricky if you don't have electronics experience. I'm in the process of doing this myself for a large Bridgelux RS array. The simpler ICs won't be able to deliver the current required, as the power switching is done internal to the chip. You then have to start looking at external switch driver designs. For the most part, using TI/Nationals Webench software on their website is the best way to get a design quickly. Be warned though, as their designs are all surface mount, and converting to through hole parts isn't always the easiest. You also start getting into ground loop issues with component placement.

thanks to both of you for the good info. I wonder why Citizen's COB leds have higher forward voltage than comparable LEDs from other manufacturers? I also looked at CREE, and Bridgelux for example, and if I remember right, they were in the 30-40V range, with higher current of course.

The specific LED part number I'm looking at is CLL040-1818A1-50KL1A1. Looking at the datasheet, It's 144.3W max, and the forward voltage min and max is 50.4 and 59.8 respectively, so it is very nearly a 10V range!

I'll look into those brands mentioned. I also found this, which seems like it should do the job if I'm using it in combination with an appropriate AC/DC power supply to power it from mains.

danieruz said:

thanks to both of you for the good info. I wonder why Citizen's COB leds have higher forward voltage than comparable LEDs from other manufacturers? I also looked at CREE, and Bridgelux for example, and if I remember right, they were in the 30-40V range, with higher current of course.

The specific LED part number I'm looking at is CLL040-1818A1-50KL1A1. Looking at the datasheet, It's 144.3W max, and the forward voltage min and max is 50.4 and 59.8 respectively, so it is very nearly a 10V range!

I'll look into those brands mentioned. I also found this, which seems like it should do the job if I'm using it in combination with an appropriate AC/DC power supply to power it from mains.

Click to expand...

Higher voltages lend themselves better to custom power supplies and also higher power of course.

Cree/Bridgelux may be targeting Class-II designs, <100W, < 42V in most places (allowed higher in the U.S.). It makes certification easier, isolation easier, etc. Perhaps Citizen thought if we are over 100W already, we may as well just go for Class-I? Though under 100W, I believe still classII in U.S. ... need to look up.

There are high voltage drivers from the likes of Philips Advanced, but you may be in voltage no mans land.

Semiman

I am also interested in that particular led for studio lighting in broadcast video . 90 CRI and 3000K fits my application nicely especially with dimming capability.
I did make a unit using 8 Cree MTG's in hi CRI 3000K clustered together for an awesome 12000 lumens that can be powered off batteries or AC.

perhaps something like this

http://www.wntpower.com/productdetail.asp?id=460

The WSS-150-2A15W model is just perfect

Sounds like building a driver may be beyond my current knowledge/experience!

Yes, the wintek driver looks like it fits the bill. I also found another one: Mean Well HLG-150H-54, DC output, like was mentioned earlier, these get pricey! Is AC or DC better for driving these LEDs?

danieruz said:

Sounds like building a driver may be beyond my current knowledge/experience!

Yes, the wintek driver looks like it fits the bill. I also found another one: Mean Well HLG-150H-54, DC output, like was mentioned earlier, these get pricey! Is AC or DC better for driving these LEDs?

Click to expand...

It's always DC at the LED, just matters what you intend to power it from.

I would go Meanwell, at least you have some guarantee of both quality and safety though if that 54 is the max voltage it is not high enough.

Semiman

It's always DC at the LED, just matters what you intend to power it from.

Click to expand...

Hmm, this is a bit unclear to me then. From looking at specs on a lot of different drivers, transformers, where input is mains AC, it seems that unless explicitly stated as DC output (like the Meanwell drivers), it's implied that since the input is AC, the output will be AC as well, (like the wintek drivers?) and if that's the case, then for the case of the wintek drivers, one couldn't directly connect the LED to the driver but would need additional circuit part, like a rectifier to convert to DC, right? But this would surprise me since I'm sure they don't want to market and sell units that can't be directly connected to drive the LED.

danieruz said:

It's implied that since the input is AC, the output will be AC as well, (like the wintek drivers?) and if that's the case, then for the case of the wintek drivers, one couldn't directly connect the LED to the driver but would need additional circuit part, like a rectifier to convert to DC, right? But this would surprise me since I'm sure they don't want to market and sell units that can't be directly connected to drive the LED.

Click to expand...

Unrectified AC to the LED will be 'on' with forward current and 'off' for reverse current. Most diodes have a higher reverse voltage breakdown than a forward voltage. For this reason, LEDs are assumed to run on DC or rectified AC.

I'm using Hyperboost driver from TaskLed for this LED. I made garage light recently with CLL040-1818A1-303M1A2. Use onboard trimpot to limit current to max you want (current Hyperboost will go up to 3.2A), then external pot to dim. You can also PWM it so you will have choices when controling it with microcontroller.
Input current should not be higher than about 5A for Hyperboost so keep you input voltage high enough, 36V or around for that LED is good (AC/DC constant voltage power supply for Hyperboost driver)

I'd go with the Thomas Research/Inventronics drivers (they are both pretty much the same, as Inventronics makes the drivers for TRP). I've been using them for years now, and find that they are more compact, more efficient, easier to use (especially is you want dimming), and more robust than pretty much any equivalent Meanwell driver. You also get a broader range of voltage and current setups, of which you will easily find a version that will work with the Citizen LED in their 150W range. They tend to be a hair more expensive, but I find it to be worth it.

I'm sure that Wintek driver will be cheaper, but where are you going to buy it? I didn't see any easy routs to purchasing the driver. Thomas Research drivers are available at Digikey, while Inventronics drivers are available at Future Electronics.

AnAppleSnail said:

Unrectified AC to the LED will be 'on' with forward current and 'off' for reverse current. Most diodes have a higher reverse voltage breakdown than a forward voltage. For this reason, LEDs are assumed to run on DC or rectified AC.

Click to expand...

OK, it's making sense now. That would in effect make it 'pulse DC' at 50Hz in my case

Use onboard trimpot to limit current to max you want (current Hyperboost will go up to 3.2A), then external pot to dim.

Click to expand...

trimpot is slang for a potentiometer, right? As I understand it, there are several different kinds, which did you use?

Lots of good info and several options to look into, thanks everybody!

danieruz said:

Hmm, this is a bit unclear to me then. From looking at specs on a lot of different drivers, transformers, where input is mains AC, it seems that unless explicitly stated as DC output (like the Meanwell drivers), it's implied that since the input is AC, the output will be AC as well, (like the wintek drivers?) and if that's the case, then for the case of the wintek drivers, one couldn't directly connect the LED to the driver but would need additional circuit part, like a rectifier to convert to DC, right? But this would surprise me since I'm sure they don't want to market and sell units that can't be directly connected to drive the LED.

Click to expand...

Virtually every LED driver is DC output. It may not say it, but it is implied. The Wintek are certainly DC output and it does say that.

Semiman

danieruz said:

trimpot is slang for a potentiometer, right? As I understand it, there are several different kinds, which did you use?

Click to expand...

I think so English is my second language but I believe trimpot is short for trimmer that is a potentiometer, i.e. trimmable potentiometer.
Hyperboost has one on board, you use it to set maximum current.
For diming you can use another external potentiometer (50kOhm logarithmic is recommended) or PWM.
I used big potentiometer that I had on hand. Garage light does not really needs dimming, I just wanted to be able tune it down if needed, have it passively cooled, running right now at about 80W and I wasn't sure how hot it will get (heatsink is pretty huge extruded aluminum about 18x8 inches with about 1 in fins)

Go to taskled website and read techical section about Hyperboost, everything is well explained.