"Home made" LED grow lights...

[MajorCoco]

Hey Rasser. I'd be interested to see how that circuit worked when pushed to high wattages. Like you, I thought the simplicity was nice and it looked to me like a sort of current "pressure valve" safety system.

It would be good to model it first though before testing it out on a $100 85W led...That's quite a step-up from it's original design wattage.

Either that, or see someone else trying it out first of course

 

[Gastanker]

That bud looks great imo. Yum.

 

[Rasser]

Ok...I got a little impatient this evening.

View attachment 2214017

That looks quite smokable

, a little pale perhaps, nothing unusual but I'm a little bit focused on that, at the moment
after watching 3 plants loosing a bit of there dark greenness when exposed to HPS for a couple of days.
And it's also visible on this picture of two finished plants grown under HPS and LED(right).

Another thing I note is the burning at the tip of the leaf, is that heat damage or light damage ?
I see the same on some of my leafs growing under LED, and I usually only see it at the top
of the plant very close to the HPS bulb and seeing it there I thought that it was heat damage.

Hehe don't we all, on my 2nd. grow I think I fast dried 75% of the buds, starting with the bottom buds and working my way up
and by harvest time not much was left. Running dry 2 week before harvest can make the grow room looks like a wasteland.

 

[Rasser]

Hey Rasser. I'd be interested to see how that circuit worked when pushed to high wattages. Like you, I thought the simplicity was nice and it looked to me like a sort of current "pressure valve" safety system.

It would be good to model it first though before testing it out on a $100 85W led...That's quite a step-up from it's original design wattage.
Either that, or see someone else trying it out first of course

Yes I'm gonna try that, buying some 100 amps and power resistors,
I hope the circuit scale up so that the 9W LED can becomes 90W and the 0.3W heat is only raising to 3.0W.
I was connecting the 12V water heater to a PC PSU via a DC watt meter and saw it drew 130W so no wonder the tiny mosfet
got a bit hot when I was using that to dim the voltage. I also got a energy meter on the mains and that said 160W, so the psu was waisting 30W
Thats to much, but it was an very old 300W psu that barely could deliver the 10 amps to the heater, a newer and bigger on wasted "only" 15W
so that more acceptable,

Using these smaller psu may work more well for loads under 160 Watts
12V 10A 120W Fanless Switch Mode Power Supply
£14.99 on E-bay UK -360W 36V for 45£ I wonder what real CC drivers costs in the totaling 360W

But I think it's only real fun if one already have to psu from leftovers instead buying new ones.

A Pressure valve is a ok analogy, it's a self correcting system, a feedback loop, from the current going through R3
Ohm law says V= I*R , so as the current goes up so dos the voltage over R3 and thats feeds the base on the transistor
witch responds with pulling the gate down towards ground, the fet responds with turning down for the voltage to the LED's
witch draw less current now, so the voltage over R3 goes down, and the loop continues.

If you wanna play with the basics of Ohm's "Law" and electronics then this online Java app is straight forward.
A guy on youtube is explaining it's functions Here
Lots of apps for phone / tables for electronic also btw.

Click image for site.

 

[gaztoth]

looking good man

 

[MajorCoco]

Cheers Gaz

 

[MajorCoco]

Ok, they've been flowering for 60 days now. More than I was expecting, but I think we're nearly there. A good thing too, because they aren't looking too clever at the moment. Most of the leaves are shot to hell, and although the damage is all old, it makes them look a bit sorry for themselves. I'm hoping that the extra flowering time is because I have a little less wattage than I should, and because these phenos just aren't the really fast ones. I've read some partial grow reports on this strain, but nothing conclusive on flowering times or phenos. Generally speaking, I'm of the opinion that the longer a plant takes to finish, the nicer the end result will be. With hybrids indy/sats it's always nice to have a touch of the sativa in the pheno, even if that means a longer flower...in my opinion.

On the plus side, I finally have some properly dried bud from a few days ago that is definitely picking-up in potency! It's the top cola from the frosty littlest lady, so I'd be pretty pissed if it did nothing. It's not exactly a great stone or high, and the buzz doesn't last long, but at least I know I'm not wasting my time.

Looks better than it smells also in my opinion, though I guess without a cure that isn't surprising.

Anyway...The plan is to chop the little'un in 3 days, then the others in a full week.

Very rough guesstimate of yield is around 3/4Oz from 2 of them, and maybe 1.5Oz from the other.

Here are the latest pics: (almost dead-centre of the first photo you can see the white stem where I topped the little'uns' main cola a few days ago)

 

[thatsmessedup]

I dont know about this grow... Kinda hopping that it would be more crystaly and white. But, pictures can be deceiving... what are your thoughts.

 

[foreverflyhi]

Keep it up homie, it looks great to me, those little bumbs u ran into are just a stepping stone to perfecting your grow

Im going to read and reread your journal

 

[MajorCoco]

I dont know about this grow... Kinda hopping that it would be more crystaly and white. But, pictures can be deceiving... what are your thoughts.

They look pretty good in real life. I'll try to get some better shots...but...
I'm not planning on growing this strain again any time soon, if that's what you're getting at. Don't get me wrong...I'm not writing them off totally. They are resilient, short and pretty easy to grow in dirt and the yield is good considering how small they are.
They are also more frosty than they look, but it don't mean a thing if it ain't got that zing...and that's probably what I'm most worried about. They don't seem to have much bite in them despite all the frost.
I may retract that statement once I've checked out the other phenos and these have had more time, but yeah. I'm a bit like...whatever about this. My big mistake was only growing one strain! I'm not doing that again. I got so pissed off waiting for these suckers that yesterday I popped 4 new seeds onto paper:
- AK47 (regular seed) - serious seeds
- Chernobyl fem - subcool TGA
- NLxBigBud autofem - World of seeds
- Lemon OG Kush - DNA Genetics

 

[Chronikool]

MajorCoco....you are an inspiration to me with your lights and your girls and your patience!

 

[MajorCoco]

MajorCoco....you are an inspiration to me with your lights and your girls and your patience!

Hehe. Thanks my friend. I'm really stoked I'm giving people the positive DIY vibes!!

The growing has been pretty easy actually...the patience bit has been the toughest!!

 

[Rasser]

Hehe. Thanks my friend. I'm really stoked I'm giving people the positive DIY vibes!!

The growing has been pretty easy actually...the patience bit has been the toughest!!

LOL yes, And that is properly what's behind 50% of the over watering and over fertilized plants problems seen,
the need to "help" the plants can be hard to resist.

Your thread has certainly put a equal sign between white LED's and good vegetative growth,
I don't think I would have ordered 4 pcs. 10W white LED flood lights, without having the pictures of your green plants in my head.

But having said that, I think using at least half of the wattage in the blooming phase on red LED light instead would have produced
better and would not bleach the plants as much as seen on the last pics.

I'm thinking about the 2700K CFL's spectrum witch don't 'bleach' much, they don't put out anywhere near the amount of green light that a white 2700K LED does.

In this image I guess the Philips bulb is covered with something,
and the first two CLF's are without.

Your are a pioneer and they often gets a few scornful remarks on the way,
and have a few set backs, that's the price, for being the first to do something new,
and if it works or it later turn out they where right, they get to be heroes.

 

[MajorCoco]

Ok, the deed is done with little miss frosty. I've had all 4 new seeds pop now, and my Lemon OG has broken the surface so I need to start making room.
(If anyone's interested, all but one of the seeds popped within 24hrs: DNA Genetics and Serious seeds first, then the World of Seeds freebie.....and finally, thank god..my Chernobyl finally popped last night!)

With this plant I have a feeling she would have kept on going and maybe filled-out a touch more, but she's well overdue, and I'm not sure the quality of the smoke merits giving her another week. I keep seeing amber trichs, but only on the sugar leaves, which is why I think she could have gone longer...

I'll try to get better bud shots when they're properly dried. Not massive buds, but they are heavier than they look. We'll see what the yield turns out to be. I've also thrown some popcorn into a paper bag with some trim, so there's a little missing from these photos...but not a lot.

Here are the pics...

 

[thatsmessedup]

Those pictures look a lot better then the last ones. Good job!

 

[MajorCoco]

Cheers! Got nice any sticky while chopping, so I'm happy!!

Of course..I'm guessing at least half of this won't survive through to a proper cure, but I'll try not to test too much before I weigh in at least!! It's good to have a harvest complete anyway. I'm already looking forward to a bit more variety in my next grow though. And some more fruity smells too...

 

[Rasser]

Cheers! Got nice any sticky while chopping, so I'm happy!!

Of course..I'm guessing at least half of this won't survive through to a proper cure, but I'll try not to test too much before I weigh in at least!! It's good to have a harvest complete anyway. I'm already looking forward to a bit more variety in my next grow though. And some more fruity smells too...

Congratulation on your harvest, and your appetite is understandable.
Just to recap, how did the grow when a long light wise, cold white LED 0-x weeks and then both LED x-harvest ?

 

[Slixxor]

I feel obligated to post! NEVER run high power LEDs I.e 1-5w without a constant current driver. Using just resistors will cause the led and the resistor to overheat. As a resistor heats it's resistance decreases increasing the current across the led. Even if you increase the resistance to to decrease the output current for the led the resistor will only produce more heat.

 

[Rasser]

I feel obligated to post! NEVER run high power LEDs I.e 1-5w without a constant current driver. Using just resistors will cause the led and the resistor to overheat. As a resistor heats it's resistance decreases increasing the current across the led. Even if you increase the resistance to to decrease the output current for the led the resistor will only produce more heat.

That would be new to me, if that was the case, checking ... Nope, at least not the normal kind of resistor we normally use.
But you can get PTC Resistors and NTC Resistors, both very much dependable on temperature.

A 10 Ohm resistor gets fried while measuring.

Since what you are describing is called 'Thermal Runaway effect' a quick search got me this:

There are resistors whose resistance increases with temperature (positive temperature coefficient). There are also resistors whose resistance decreases with temperature.


You have a constant voltage across the combination of a diode and a resistor in series.

How much of the constant voltage drops across the diode and how much of it drops across the resistor has to do with the relative resistance of the two components.

If temperature increases, the effective resistance of the diode drops.
Then, a smaller portion of the voltage will drop across the diode. A small reduction of voltage for a diode results in a significant reduction of its current (exponential IV characteristic). That is what stops thermal runaway.

So, even a resistor whose resistance decreases with temperature can still stop thermal runaway since a resistor has a linear IV(current volt) characteristic.

Source: http://forums.anandtech.com/showthread.php?t=1868907 - Thermal Runaway prevention.

Edit: and it's the combination of cheap DC volt and a constant current driver that looked interesting,
it still depend on the actual waist when using many smaller PSU's vs- a single.

 

[MajorCoco]

Congratulation on your harvest, and your appetite is understandable.
Just to recap, how did the grow when a long light wise, cold white LED 0-x weeks and then both LED x-harvest ?

I've basically been running with all of the lights, all the time! So really we need to compare my grow of 170W LED + 150W CFL against a 300W CFL-only grow to see what benefit the LEDs are giving...

I'm not sure that we can take too much "scientific evidence" away from this except to say that it looks likely that mixed-white LEDs can provide excellent results in veg, and good results in flowering, but that you still need to have 25000 lux minimum for a really great grow result.