NorthernHize
Well-Known Member
I currently have two cxa3070's, I also have two meanwell lpc 60-1750. Could I power a pair of my cxa's per driver and still have good results. So in other words have 4 cxa's and my two drivers?
Led driver dilemma
- Thread starter NorthernHize
- Start date
AquariusPanta
Well-Known Member
You'd need to run the CXAs in parallel in order to share the available potential (voltage) delivered from the driver (34V).
But does the 3070 version run that low in voltage, despite the low amperage? You might have to try using the LPC-60-1400 instead (42V high).
NorthernHize
Well-Known Member
The cxa certainly runs off my driver and is quite bright I have them hooked upright now. So in parallel the voltage stays the same and the amps get divided. The amps are my question for driving two cxa's per driver.
AquariusPanta
Well-Known Member
I imagine you could run multiple CXAs off a single driver, all ran in parallel, as long as the driver could satisfy the COBs' voltage needs.
NorthernHize
Well-Known Member
I agree, I am just wondering if there is a formula to figure out if the available amperage will produce enough light for two cxa's in relation to growing our little girls.
NorthernHize
Well-Known Member
Good point, thank you.
nogod_
Well-Known Member
The lower the amperage, the higher the efficiency. If youre running 2 x 3070s @ 875ma they are going to outperform 1 x 3070 @ 1750 in every way [Spread, heat, par]
Your driver may power your chips @ 34v but youre probably shooting the drivers efficiency by doing so. Over the course of many cycles a more efficient driver pays for itself so most of the time cannibalizing parts is really just about saving more plastic crap from ending up in the landfill than it is about saving $$$.
Your driver may power your chips @ 34v but youre probably shooting the drivers efficiency by doing so. Over the course of many cycles a more efficient driver pays for itself so most of the time cannibalizing parts is really just about saving more plastic crap from ending up in the landfill than it is about saving $$$.
NorthernHize
Well-Known Member
So just find 4 drivers with a higher voltage rating and half of my amperage?
SupraSPL
Well-Known Member
Yep, you could use these $11 drivers and get 880mA with 90-91% driver efficiency
http://www.fasttech.com/product/1320606-85-265v-30w-high-power-constant-current-led-driver
Lots of 700mA drivers on eBay if you prefer an enclosed driver.
http://www.fasttech.com/product/1320606-85-265v-30w-high-power-constant-current-led-driver
Lots of 700mA drivers on eBay if you prefer an enclosed driver.
Mechmike
Well-Known Member
For a few dollars more you could have the best. You might consider the Meanwell HLG-185H-C1050B. >92% efficiency, dimmable, and it can drive from 3-5 CXA3070s at that efficiency. Check out the spec sheet...
NorthernHize
Well-Known Member
I figure that driver and my four 3070's in my 3x3x4 grow box would kick ass!
reasonevangelist
Well-Known Member
i reckon that's some good figurin'
Mechmike
Well-Known Member
It would. Dimmable drivers are super nice because a plant's need for light varies over the growth cycle and dimming provides a way to match those needs. I have a Kill-A-Watt meter plugged into every light I built so I can see exactly how much power it uses and I also use a Apogee quantum light sensor to measure the intensity. With these 2 tools and a dimmable driver I can give the plant exactly the amount of light it needs at every stage of growth and save power too.
UKpeanuts
Well-Known Member
Would you mind explaining this a little more, I'm not sure I really understand;
If we take 2 drivers with the characteristics;
d1 = 1000mA @ 34V - 34W
d2 = 1000mA @ 37V - 37W
As far as the COB is concerned at a 1000mA its going to output the same amount of light energy irrespective of the driver voltage.
This means that we will get best efficiency from the system if we allow the COB to operate at its highest acceptable voltage?
Thanks, UKP
JavaCo
Well-Known Member
With Constant Current drivers we have no control over the forward voltage. Resistance of the COB powered on is what sets the Forward voltage. So if you have a COB with a Vf of 36 volts and you put it on a driver that has a max of 34 volts it wont run. Now say you have a COB that has a Vf of 32 volts it will still run at 32 watts on either one of those drivers. amps multiplied by voltage gives you watts so 32 volts x 1 amp = 32 watts.
NorthernHize
Well-Known Member
One thing I want to say from personal experience is that the 3070 has a vf of 38v. But I currently only drive it with 32v and it runs fine
JavaCo
Well-Known Member
cant be both if your driving it @ 32 volts it has a Vf of 32 volts.
Mechmike
Well-Known Member
Most drivers have a bit of headroom voltage wise. So, if the rated output is 32v, the driver may not register a fault and go into 'hiccup' mode until it hits a higher than rated output. Sometimes they will work when pushing more than rated voltage but there is usually a cost in terms of amperage.