DiY LEDs - How to Power Them

If you have an accurate voltmeter you can check the voltage drop on each side of the wire. That allows you to calculate the efficiency loss. For a short run it would be fine but for a long run it might cost you some nugs.

ok, .. (looking for a simple way to use mains power) any reassurance or laughter welcome, am I on the right track -thinking- I can use a suitable step down driver off a main power supply (driver)?

eg. Power supply puts out 20-210V driving 4 CXA (@700mA) with in series meanwells LDD, input 9-56V output 2-52VDC/700mA... and then...
driving fans or UV or whatev off that driver.. ie anything up to high 40v's collected?.. just drawing the voltage they need (@700mA)??

rather than 'needing' to use separate 12v power supply/wiring for fans etc

I don't fully understand what you wrote but I am guessing you want to power the fan basically in parallel with the diode array. It could be done but is going to involve some more electronics if you care about efficiency. You could just use a series resistor in the fan lead but you will be taking 100s of milliamps to do it and have to rob current from the array to do it. Save a lot of hassle and use a separate fan psu.

cheers ballist, i nearly lost what I was trying to say myself. Yes, basically (i guess the LDD acts as a series resistor). Then to run 2 x 12v /1.6 watt fans and maybe a couple of supplementary strings (8 or 10, 3w/) through low voltage timers.. and It just works out well (for me) wiring wise.

my way to run the fan(s) and leds. old stuff from 2012

the fans are running at 50 mA. set by the diode/resistor.

the LDD is not build for driving fans.
better use the SCW12C-12 / SCW05C-12

Ok, there are big gaps in my knowledge, trying to see to far ahead maybe. So- thanks goud, and thanks for chasing up the drivers. I'd have to buy a new one anyway so might just get a bigger mains > 12v supply and run supplementary lights through 12v drivers (which I have).

hi SupraSPL ............can i link or post your thead/s or pics or vids in my spanish thread?...



saludos

Here's my micro cabinet. 2x Vero 18 at up to 1.67A - close to 100W at full speed.

I've been having so many problems with really bad chlorosis on top leaves, clawing leaves and red stems - complete growth stall.

It was too much fucking light. So I dialed it down.

Right down.


One vero 18 at ~840mA. Total less than 25W.

I used to have 240W of CFL in there.




Hope this gives yall some idea of the output of these in a small space.

Ha, I came here to look then ask what others are doing with COB seedlings. About to put two under a CXA @ 25w but it only has about 18" max under the light..
Is that too close? Was under 25w CFL.. normally wouldn't hestiate but don't want to fry them to find out what distance you at smokey?

smokey the cat said:

I've been having so many problems with really bad chlorosis on top leaves, clawing leaves and red stems - complete growth stall.

Click to expand...

Smokey do you give extra magnesium (and calcium), they need a lot with so much light. I think red stems are normal and clawing is N overfert.

MrFlux said:

Smokey do you give extra magnesium (and calcium), they need a lot with so much light. I think red stems are normal and clawing is N overfert.

Click to expand...

Definitely agree with your diagnoses of the nute symptoms, but my testing showed that it was unrelated to what the plants had their roots in.
I've played around with no food, more food, epsom salts, ph etc etc etc with a decent number of different plants. This is a clone I've grown for about 6 years now.


I think the light intensity was seriously fucking with the plant's ability to run chlorophyll in the top layer of growth. I think tissue testing would show exactly what was going wrong, but my theory is that the intensity meant the the plant was unable to process magnesium, sulphur or iron which lead to a cascading series of deficiency symptoms. There would eventually be compete breakdown and interveinal chlorosis would turn to necrosis.

As light intensity dropped the leaves straightened, newer stem growth returned to green, and chlorophyll flooded back into the healthier leaf tissue.


Hasten to add that this is not confirmed scientific fact. This is just one grower's experience with a single cloned variety. Perhaps hydro, a more competent soil grower, or different strain that wasn't selected for low light performance, would behave entirely differently. Perhaps spraying the foliage with a silica supplement could have helped protect the leaf's metabolic processes. Maybe the narrow cab and Mylar are no beuno. And maybe a bluer light source wouldn't have dumped so much energy into the top layer of tissue (3500k tested).

And of course, I don't have a light meter! Duh... haha. Too fucking easy!

At some point light intensity must be too much for normal leaf operation - my testing seems to show that in my tiny cabinet I was way over the limit with a single Vero 18 @ 50W.

Just to give you an idea of what changed as light intensity lowered - this is one of the test plants that I've kept on as a mum. You can see the deep red stem colour at the bottom changed completely, and how the lower growth still exhibits major damage.



Long internodes as this plant has spent the last month kicking around the house with indirect late winter light.

Tazbud said:

Ha, I came here to look then ask what others are doing with COB seedlings. About to put two under a CXA @ 25w but it only has about 18" max under the light..
Is that too close? Was under 25w CFL.. normally wouldn't hestiate but don't want to fry them to find out what distance you at smokey?

Click to expand...

I only have 90cm (36") from floor to ceiling in my cab and the mylar-LED combo might be more trouble than it's worth.

Harden them off and keep a close eye on them is my advice. You'll soon see if things are going wrong and a day or two of damage isn't the end of the world in veg.

You'll find that CFL to LED is amazing in terms of power efficiency - you'll be shooting 100% of the photons towards the canopy, where CFLs only expose half their tube to the leaves at best.

smokey the cat said:

I think the light intensity was seriously fucking with the plant's ability to run chlorophyll in the top layer of growth. I think tissue testing would show exactly what was going wrong, but my theory is that the intensity meant the the plant was unable to process magnesium, sulphur or iron which lead to a cascading series of deficiency symptoms. There would eventually be compete breakdown and interveinal chlorosis would turn to necrosis.

Click to expand...

For what it's worth I've seen what you describe with some older clones that were kept severely rootbound. The roots can keep the plant fed at lower irradiance but start to come up short when the light increases. No idea if that applies to your situation.

MrFlux said:

For what it's worth I've seen what you describe with some older clones that were kept severely rootbound. The roots can keep the plant fed at lower irradiance but start to come up short when the light increases. No idea if that applies to your situation.

Click to expand...

These were pretty fresh transplants, and I tried to account for over (and under) nutrition and hardening to the light. But then I'm certainly not a good grower when compared to a master like you - your cab is insane. Anyone who hasn't seen it should take a look at what I consider the best grow cabinet on the planet.


I'd be interested if someone else finds their light over-saturation point and how the plant breakdown looks like compares to what I saw. I'm picking that too much red light would be the way to do it - get the the photons to dump their energy right in the first layer of leaves.

And you better believe that on my next veg cycle I'm going to be ramping the lights back up again - "moar power!" Such a shame to have to run at 25% of designed capacity, haha

I was wondering, now that I have finished all the soldering; if the wire gauge I used is too thin. I have 4x 3070 that will be driven by a HLG-185H-C1050*, so around 150VDC total. The length of the series loop will be around 24' from + to -, I did the soldering with 18 AWG 300V insulated copper twisted wire and then realized that the drivers have 16 AWG. Right now there is only about 3 feet of 18 gauge in the 24' loop, the rest is 16 gauge.

My question is, should I swap out the 18 gauge for 16 gauge? What are you guys using?

I think it should be fine I'm just looking for others opinions.

...epic this maybe help you...

http://www.rapidtables.com/calc/wire/index.htm

http://www.rapidtables.com/calc/wire/voltage-drop-calculator.htm


thanks for your like SupraSPL... but then... ...can i... yes or not?...


saludos

Id be honored Salmontin, thank you for asking

EF, your 300V 18ga wiring is sound as far as voltage, current and length, no worries I use 18 gauge for all my runs as well and some have been up to 1.4A with no significant voltage drop.

BIG THANKS SupraSPL

..."solo" me queda BuenoTime y SDS... ...poco a poco...

...haste kills...

saludos

DQ no: 5
hmmm, two cobs running off a driver.. no worries. So then I put a switch on one and instead of switching off it still glows off but glowing! No drama like, but is that ok, glowing (in wondering)? Maybe the switch isn't good enuff...

DQ no:6
I put some fans on a dimmer, this one , it was only a cheapy but maybe it's underpowered, it comes from a 16w power supply and the PS starts to whine as soon as any real dimming happens

Edit: no;5 switch was (somehow) cactus