DIY 150-900W fully modular LED lighting driver

[PicassoCT]

And LEDs are the actually best alternative. Those energywasters the herb-growers utilize, they are to wastefull.

[varikonniemi]

Today i finally finished the 300W module. I had some trouble with the current regulation, but managed to make it work in the end.

This is 27000 additional Lumens shining down on my chilis :)

Next up is experimenting with the bag of 1W 90 Lumen 660nm LEDs

[varikonniemi]

Now this is a prime example of how it is easy to go wrong while buying stuff from china/taiwan/korean manufacturers.

90 Lumen / W is theoretically impossible at 660nm, as the Lumen is defined as based on the sensitivity of human eyes. The theoretical maximum is 43 Lumens / W @ 660nm, assuming 100% efficiency. Good LEDs typically have efficiency of ~50%.

It was a good thing i only buy stuff from sellers that are covered by ebay's buyer protection. I contacted them and mentioned this, and they immediately apologized for presenting the wrong information "they had got from the product manufacturer" and promised full refund and i get to keep the item :)

[Beherith]

How many and what color temperature/combination of colors would you suggest for a 200L aquarium that has lots of well growing plants with 2x30W 4200K old fluorescent tubes?

It draws more than 100w at the plug as measured by a power meter, (a lot of heat from the ballasts) and I want to reduce this to 1/3 while keeping light intensity (and also adding pwm control for dawn/dusk/moonlight simulation instead of current off/on timer)

[varikonniemi]

A 50W Actinic hybrid LED is probably what you would want to look at, they are especially developed for that use. Some commercial dimmable 50W LED driver is not that expensive either.

Look around eBay and search for "50W actinic led" and you will find many options. Of course this is by some measure the DIY way, as you have to mount the LED and figure out how to cool it (actively or passively) and connect the wires from the driver to the LED.

I have no idea about "plug and play" ready made aquarium LED lights, i focus on DIY

And remember, buy from someone who has earned ebay buyer protection coverage, that way you minimize your risks.

[Beherith]

Im pretty handy with DIY stuff, I can solder SMD and code in AVR assembly. Ill look into 'actinic', thanks!

[zerver]

Nice to see someone doing almost the same thing as I am. Although I have no *cough* "chilis" but I am more interested in normal household lighting.

The currently available LEDs with regular socket designed for line AC voltage are a truly sad story. The AC/DC module built into EVERY lamp has a much shorter life than the LEDs themselves and they are ridiculously expensive.

The solution is indeed to have a separate power module for the whole house. My plan is to install dimmable LED strips in every room, along every wall, near the ceiling. You can get them cheap on ebay.

I hope more people will realize this is the way it should be done, but I fear the average user is to lazy to install some new power cables to supply DC to lights around the house.

[PicassoCT]

You all could use some weed to fight those coughs you get when pronouncing words like chili..

[zerver]

Chilis are strong, of course they cause cough.

Bayer Heroin "the sedative for coughs" is a better remedy

[varikonniemi]

Yes!


I have 3 Naga Morich chilis (the smallest ones), they are the hottest chili in the world =)

And some others...

[Saxena]

Any reason you went for white leds instead of the red/blue mix that most led grow lamps use? led strip lighting
led strip lighting outdoor
12v led light bars
Looks cool, your electrical know-how is impressive.

[varikonniemi]

Any reason you went for white leds instead of the red/blue mix that most led grow lamps use? led strip lighting
led strip lighting outdoor
12v led light bars
Looks cool, your electrical know-how is impressive.

Sorry i did not catch your question earlier. What drove my design was primarily price, and those white 50W and 100W modules are half the price compared to colored ones from same manufacturer, not to even mention more credible manufacturers. And they do not make the correct 660nm red but only 620nm.

I figured the warm&cold white combo would be a nice wide-spectrum natural-ish light source and so far these have exceeded my every expectation.

The light has been in 24/7 operation since it was finished, with a combined downtime of under 15 minutes in 7 months (changing the initial under-rated 12V psu for the fans.)
(no, i have not finished integrating it as was planned, i have not really worked on this project after i finished the 300W module. (I got a bit frustrated with the bizarre behavior of the lm350 when running at high voltages, as the voltage level should not affect anything, but it clearly does.)).

[Beherith]

An LM350 can be super inefficient, have you tried current limiting with a powerFET?

[varikonniemi]

I have used the lm350k extensively in the past as it has excellent features and the performance has been adequate up till this point. And i just so happen to have a bag full of them and cooling elements with pre-drilled holes for the mounting and pins. The double diode method i ended up using on the 300W module is only the second current limiting model i have ever built.

What kind of circuitry do you have in mind?

edit: i just realized i hd mixed up the names of the zener and double diodes version, fixed now. This is what i currently have, do you think what you suggest would improve on it in any meaningful way?

[Beherith]

I like this method of driving power leds: (this is only feasible up to approx 1-2 amps, because it needs accurate and small resistance values)



The transistor opens at about 0.55V, so if you want to drive 1 amp of current through the powerfet, then you need to set Rs to 0.55 Ohms. Rg can be anything in the range of 10K-1M.

The advantage of this circuit is that it accepts a wide range of input voltages, and can drop as little as 0.6 volts, so you waste less power. It is also quite resistant to ripples and spikes in the supply. Transistor can be any generic one you have laying around.

[varikonniemi]

Yeah, 2 amps was also fine with the lm350. I got to about 2.6A before it started oscillating and at 2.8A it stopped regulating altogether and leaking unlimited when running the leds at 115V. It worked fine to 3.5A with a load resistor and ~80V so there was something very odd about the failure mode.

I need 3-3.2A.

I would like to believe that what i have is good design because of http://en.wikipedia.org/wiki/KISS_principle :D

[Beherith]

Using a fet isnt much more complicated, and an Rs resistor of 0.15 ohms is still relatively easily obtainable. Also, you can add diodes between the emitter and the ground to increase the voltage drop between the fet source and the ground, so you can use larger Rs resistors.

Though 80V at the gate of the FET might be too much, and may need and additional resistor between the emitter and collector of the transistor to drop it..

The above fails KISS.

[varikonniemi]

Well this is something rare, i finally get to announce a completed project!

After one and a half year of searching i finally found a suitable PSU and decided to finish this. The LED guard i came up with is something i am especially proud about since similar level of protection is found only in the most expensive commercial lights.

For all your engineering needs you can always count on varikonniemi. That is if you are not in a hurry.

[hoijui]

what are you doing with it?
you just create and test it, or are you gonna grow plants for real, with it?
from the photos, it looks like you are just testing.
.. or will you give it to someone else?

[varikonniemi]

I have grown some chilis, and this winter i am going to try growing tomatoes. I already ordered some tasty varieties. I would love to have a room dedicated for indoor gardening but the best i can do currently is one corner in the basement.

I certainly would not need anywhere near this much power, but you know what they say...

Actually i have to admit that i have been thinking about rebuilding the regulation lines to use 3x300W isolated rails but i have not yet been able to justify to myself the purchase of three more LEDs even if they are dirt cheap nowadays