Choosing the correct driver

StonerCol

StonerCol

Well-Known Member
Hello guys n gals....
I was wondering how I would go about choosing the correct driver for a DIY build I'm doing soon? I ask this specifically rather than wanting someone to say "Just use driver xyz, it'll be fine." I'm no electrician but I've kinda sussed out the relationship between Volts, Amps and Watts but wouldn't really have an idea how the theory works?
Thanks in advance for the help.

:peace: :weed:
 
Nugachino

Nugachino

Well-Known Member
Okay so here's an example. I was only going to be purchasing 1 Vero 29C (69.4v) for my 1400mA driver. But it turns out the minimum voltage on the driver was 8volts short of being able to fire up that cob. But in order to have it work properly. I either had to add in another cob. Or swap the driver.

Adding the second cob of choice to the fray made it far too high a current for that driver. I ended up picking another driver whose minimum and maximum voltages and output current matched up with what the two cobs would need to operate properly.

So when a driver says it can run 1x 36v cob at 1400mA. Basically it means you're limited to cobs that only take 36v to operate. And they also have to be able to handle that 1400mA (1.4A) drive current.

Hopefully this makes some sense to you. I'm not that great at explaining things.
 
StonerCol

StonerCol

Well-Known Member
Nugachino said:
Okay so here's an example. I was only going to be purchasing 1 Vero 29C (69.4v) for my 1400mA driver. But it turns out the minimum voltage on the driver was 8volts short of being able to fire up that cob. But in order to have it work properly. I either had to add in another cob. Or swap the driver.

Adding the second cob of choice to the fray made it far too high a current for that driver. I ended up picking another driver whose minimum and maximum voltages and output current matched up with what the two cobs would need to operate properly.

So when a driver says it can run 1x 36v cob at 1400mA. Basically it means you're limited to cobs that only take 36v to operate. And they also have to be able to handle that 1400mA (1.4A) drive current.

Hopefully this makes some sense to you. I'm not that great at explaining things.
Click to expand...
Thanks for the reply....tbh your example didn't help me understand the theory but I do appreciate that you took the time and effort to reply :)
 
Nugachino

Nugachino

Well-Known Member
For my setup. I've got a 1.5 x 1.5 ft square. It takes about 30-50w of light per sq foot. So anywhere between 90 and 150w to light my space.

This is where things get tricky. You can run two, four or however many cobs you want in that space. But the less cobs you've got. The harder they have to be run in order to output enough light to cover the area.

The more cobs you've got. The softer they can be run. Soft run typically means more efficient output and better light spread. But it also means a more complex build. And typically a higher starting cost to get said light up and running.
 
Nugachino

Nugachino

Well-Known Member
Honestly. Choosing the right driver depends on what area you're looking to light up. And how efficient you want those lights to be running. The other thing is budget. More parts usually means more cost.
 
Nugachino

Nugachino

Well-Known Member
I started out like you. I didn't know shit about cobs. I thought blurple was as good as whites. Turns out those newer Veros crap on my old blurple. Not only because there's two cobs to the blurple lights one cob. But, their overall output per cob actually makes my old light looks like an over priced toy in comparison.
 
StonerCol

StonerCol

Well-Known Member
Nugachino said:
Honestly. Choosing the right driver depends on what area you're looking to light up. And how efficient you want those lights to be running. The other thing is budget. More parts usually means more cost.
Click to expand...
Yeah, that's why I want to understand the theory/process so I can make informed choices and look for other alternatives to the Meanwell drivers :)
I'm expecting the answer to be something along the lines of adding up Watts/Amps/Volts of the light blah blah blah......
:peace: :bigjoint:
 
StonerCol

StonerCol

Well-Known Member
ganjafather27 said:
Have you watched any growmau5 videos on YouTube? He explains everything you want to know plus more
Click to expand...
Yes but not for a while and I must have missed the one(s) where he explains this issue...I'll go back to those and have another watch...that's a good call...thanx man :)
 
nc208

nc208

Well-Known Member
I grabbed this from RAPID led's led university.
"
How Do I Know Which Drivers To Use?
The first decision to make is whether you want a dimmable or a non-dimmable driver. Dimmable drivers have a few advantages:

  • Tweak color temperatures to your liking (if you have multiple drivers)
  • Acclimate tanks more easily
  • Compatible with many reef controllers (ie. Apex, Reef Angel, etc) for sunrise/sunset simulations
Once you know which type of driver you need, you’ll need to look at the current (mA) output of the driver. For non-dimmable drivers they will only output one current level. For example, the LPC-35-700 driver will output 700mA at all times, regardless of how many LEDs are attached to the driver (assuming you’re running one string in series off the driver, as opposed to say multiple parallel strings).

Dimmable drivers on the other hand have variable current levels. Please check the product description page and/or technical data sheets for the current range. For example, the ELN-60-48D driver outputs a current of 0-1.3A. Since the driver can output a max of 1300mA, this driver may be too powerful for some LEDs (ie. Red and UV LEDs can only handle 700mA) unless you dial down the maximum output current via the driver’s SVR2 knob (Mean Well drivers only).

To figure out how many LEDs a driver can run, you’ll need two pieces of information: the driver’s voltage range and the voltage required by the LED at the given current level that you would like to run the LEDs at. As an example, the LPC-35-700 driver has a voltage range of 9-48V. The XP-G Cool White LED requires 3.05V at 700mA (remember this is the current output of the LPC-35-700 driver). Thus, the minimum number of LEDs required is 9V divided by 3.05V. 9/3.05 = 2.95, thus we round up and the minimum number of LEDs is 3. For maximum LEDs, we divide 48V by 3.05V and get 15.74. We round down and get 15 LEDs. Typically we play it safe and thus on our product page we list the range on the LPC-35-700 driver as ~3-14 LEDs. Keep in mind the voltage required by each LED can be quite different so you may need to do these calculations for each of your strings."

source" http://www.rapidled.com/led-university-1/
 
nogod_

nogod_

Well-Known Member
Every cob has a set voltage that really doesnt vary much. You control the current and in doing so you control the power.

So really all youre doing is picking how hard you want to drive each component (10watts? 50watts? 100watts?) And then dividing that wattage by the set voltage of the component to get your drive current.

If youre using a 36v cob and you want to run it at 50watts then youre going to pick a driver that can supply your 36v cob with 1400mA of current.

There are two ways of picking a driver at this point.

One is to pick a constant-current driver that will always supply your string of cobs with 1400mA. In this case you will be wiring your cobs in series because in series no matter how many cobs you add or subtract, the current remains the same. With every cob you add or subtract from the string, only the voltage changes. For a 200watt string of 4 x 36v cobs wired in series, the cumulative voltage would be 144v. So you would need to find any constant current driver with an output of at least 144v (more to be safe) and a fixed current of 1400mA.

The other option is to wire in parallel. In this case you will be looking for a constant voltage driver with a fixed voltage output. In the case of the 36v cobs you will be looking for a driver with a 36v output. You determine your drive current by taking to total output current of the driver and dividing by the number of cobs you are trying to power. In the case of the 36v cobs that you want to run at 50watts using 1400mA of current, you need to find a driver with 5.6amps of output.
5.6amps/4cobs = 1400mA per cob

Hope this helps, there are many ways to play with combinations of series/parallel to make your driver work, but thems the basics.

StonerCol said:
Hello guys n gals....
I was wondering how I would go about choosing the correct driver for a DIY build I'm doing soon? I ask this specifically rather than wanting someone to say "Just use driver xyz, it'll be fine." I'm no electrician but I've kinda sussed out the relationship between Volts, Amps and Watts but wouldn't really have an idea how the theory works?
Thanks in advance for the help.

:peace: :weed:
Click to expand...
 
Moflow

Moflow

Well-Known Member
StonerCol said:
Hello guys n gals....
I was wondering how I would go about choosing the correct driver for a DIY build I'm doing soon? I ask this specifically rather than wanting someone to say "Just use driver xyz, it'll be fine." I'm no electrician but I've kinda sussed out the relationship between Volts, Amps and Watts but wouldn't really have an idea how the theory works?
Thanks in advance for the help.

:peace: :weed:
Click to expand...
What chips/strips/boards are you thinking of using?
:cool:
 
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