Turning coal into...Ok ..Silver!

There are some people out there who have bought 'Eastern Originating " led grow lights .
Which in most of cases ...
Well they didn't 'live up to their myth' ,as the latter was advertised...
The treasure proved to be nothing more than coal ...
And they ended up in dark storage rooms ,or as vegging lights ...
Or to shine along with some awful HID lamp...

Can they be turned into something decent ?

Not gold,but at least silver ?

Well ...Do not expect miracles ,but yes they would be able to veg and flower,way better than before ....

What it takes to do it ?

For starters some basic paste/glue applying skills and some basic soldering/desoldering skills.
And some new cheapo leds ...

Later if one wants to mess further with drivers and cooling
(Let's name it "Second Stage of Tunning of A $hiity led light " ),
maybe some basic wiring and drilling skills might be helpful ...

Let us stay for present ,in the First Stage of tunning ....
Changing the leds ( Light Quality wise firstly and then Light Quantity ) ...


Why those led fixtures did not work firstplace ?
Why they gave such poor growth and final yields ?

Well ...That's a tad complicated ...
It's rather a series of ....really bad designing faults...

The history of led utilisation in horticulture starts like an old movie...
Not black and white..Not with shades of grey ...
But in Blue and red ..With shades of violet/magenta...
Weird extraterrestial light...
Always reminded me of Dr.Who tv-series ...
(I do not know exactly why's that so ...)

First researches with leds regarding horticultural utilisation ,
were done with the available then leds.
Only monochromatics .

With promising results ...

Yes.But on which kind of plants and in what growing methods in particular ?
And for which final purposes ?

Promising results where shown in green leafy plants vegetables and herbs ...
In bedding cultivating methods ..
Tests and experiments done 90% with plants that do not need great amounts of light in order to be cultivated ..
That was then ..

The idea of using leds as a supplemental greenhouse illumination was there from the start.
Space Exploration people also were interested in leds,in order to provide food and oxygen to Star sailors ,
while getting rid of CO2 and..the rest of human secrements ,feeding them to plants ....

As a greenhouse supplemental light or as main light source for non- light needy plants ( <200umol/m^2) Red and Blue leds are
more than ideal and enough.And at their maximum efficiency working state.

Blue leds are the most electrically efficient leds ,Deep Reds are following ( OSlon Hyper red bin T4 :49% efficiency @350mA )..
No question about that .

Greenhouses do not have reflective walls .
Light cones of leds should be 'concentrated' focused at the plant beds beneath them,with the least possible light escaping sideways...

Why all that prologue?

Ha! In order to understand what happened and still happens next ....

So..
What happened next ?

Ha-ha-ha ..

Now it starts to get comical and tragical...

First 'serious' and world-known companies released led horticultural fixtures for the
horticultural industry.Not for the average home-grower ....

These early led fixtures where at 99% ,combinations of blue and deep red leds along with narrow beam lenses .
Specially designed for large greenhouses.Not for grow-tents nor even for 9' tall grow rooms .

Spectra was and still is the minimalistic ,most-electrically efficient supplemental light to natural sunlight ,
or as the only light source for young and/or non-light needy plants .

( Later researches came to show that as light intensity increases ,then red and blue wls ,are not enough by themselves.
Plants won't grow normally under 1000umol/m^2 of magenta light...
Neither the yields are worthy of the power spend ...
Plants need all the rest wls of PAR from certain levels of irradiance and up.
Let alone the photomorphogenic and rest biological value of these missing wls.
Specially for flowering and fruiting ,light-thirsty or even 'bulimic' plants..like mj is. )


And here starts the misunderstanding ....

Smaller companies start to pop-up ,seeing the opportunity of profit...
But their target is not the greenhouses ,but the average home grower...

Those companies lack almost any scientific knowledge about horticulture.
In many cases they lack any knowledge about leds ,whatsoever ...
Or they simply do not care to apply it ...

So they start mimicking the 'giants'...

And massively bringing led lights to the home-growing market ,
with a wrong spectrum that is intended for other uses not as sole light source,
or for totally different plant species and cultivating methods if used that way...

Yes..ufos are wonderful..for parts that is

Slowly,it was revealed that home indoor growing with leds ,
is not done successfully by red and blue leds alone.
No matter if cheap or expensive leds .

Many grows using other wls or white PC leds ,showed that things are totally different ,than what was previously and commonly believed...

"Hey,green light is useful(if not mandatory ) when you hit your plants with >1000umol/sec/m^2 .."
Swedish scientists speaking..

"Hey ,you need ambers and lower reds ,also,as power increases ..."

"hey,you need this ..."

"that ..."

In short ?

You need white light .
All the PAR range .
At least for that particular species of plant,that you're growing,bro..
If it was carrots ,I would suggest you otherwise...

Mainly (but not only )'Eastern" led light companies,
really think many people are totally stupid.
Well..They ain't that far from truth,anyway...
All people can behave stupidly at occasional cases/circumstances...

So they constantly try to sell BS as wonder growing lights ....

....

Why those light suffer ?

For many reasons which add up ...

1) Spectrum: Even if it's not just red and blue leds ,but some 'multi-band light ,still things won't just get better.
If narrow beam lenses are used ,things just get worse...
It is way tricky to design a multiband monochromatic led light.
Uneven heating -different voltages/currents-and the most serious the uneven wls distribution.
Light lacks 'diffusion' ,'homogeneity'...Different parts of canopy get different relative spectrum peaks ..
Messy ...

2) Blue leds ....Even the eastern cheapos are powerful enough for flowering mj ...
They mess everything up,in flowering with their extreme blue radiant power...

3) Red leds ....Usually not made of efficient chips(the eastern ones ) except those made by the Taiwanese Epistar.
As cooling design is also poor in those led lights ,red leds drop really much in output power and efficiency after some operation time.
Blue ,which do not have such big problem like reds ,start to 'dominate' ..
Things just get worse and worse ...Specially during flowering ...

At vegging...Well that's why they veg so good,those cheap eastern BS ...Not any FR ,low reds and lots of blue ...
Way compact growth with huge dark green leaves.And all the nitrogen / water vanished from tank ...
(Due to increased protein synthesis and widely opened stomata,leading to excess transpiration,respectively..)

4) Poor cooling ("sample" of a heatsink,good only for keyring.....crappy noisy fans ..bad,restricted airflow,etc )

5)Poor driving ( Not utilising CC drivers but resistors and zener diodes,unefficiently high- driven or even overdriven leds. )


Those are the main reasons ....
Let us try to "fix "the first three ones ....

Ok...Now I will wait for a volunteer ,to show me an 'Eastern' worthless led light ,to have it as a tunning basis and as an example...

And further analyse which leds should be replaced by which and why to use those and not these...

While waiting ,I will expose some personal experiences with the famous 8mm Eastern( cheapo ) leds ...
(Also called 'Seoul Type " )



Anatomy of a led : Their case is made of a thermoplastic polymer,usually white.
Inside at the case center sits a 'mirror cup'..
That is because their chips are "volume emmiting " and
not Thin /top-layer/film emmiting like the more expensive,smaller(and efficient) ceramic cased branded leds .

They are covered with a PMMA lens usually providing an 120-140° emmision light cone.
Inside the chip is enclosed in a super-transparent soft silicone hemispheric blob...

Lenses tend to come off pretty easy.

It has two silver plated copper connection pins ,usually with the cathode marked " - " ,
but not so rare the anode is marked also with a " + " ...

Underneath there is a silver plated copper circular base ,the thermal pad.
It is in direct contact with the led chip ,so it is not electrically isolated !



There's a country with a long wall ,that can be seen from space,
that manufactures these leds in millions of pieces ...
People's Republic of ...
Ya know...

And they are in trade business for thousands of years ...
Long experience.
And they are thirsty for profit.
They are part of the B.R.I.C.K. team....


So ,they do anything,with profit in mind.
Even regarding leds designing ,manufacturing and selling...
Specially there.
A huge market with luminus future.

Let me reveal some secrets of their 'trade' ...
How they master the art ,to make profit ....

For the very few members of this site that went against the majority of posts here, and bought a Chinese low end light thinking they were getting value for money ...?
2 choices really, ...... use the light for some other purpose, germing, mother plant, fish?...or sell it, or as sailor recommends.............. rebuild it...?

I know what I will do ...."Stick with the majority and never have that shit in the first place"

LISTEN TO THE ADVICE AT RIU.org..................... ITS FREE!

By now ,many if not most of the small or bigger led factories there ,somewhere south-west in that country,in the 'la-led land' ,
they use patents selled or released from Bridgelux for the blue dies .Also they have great experience into making red chips ,at
the range of 620-640 nm . Their <620 nm ambers and >640 nmm deep red chips,really suffer efficiency-wise even today,as we ...speak..
(Sort of .. )

So they do make decent blue chips ( 430-470 nm ) and red ones ( 620-640 nm ) ....
All the rest of the chips they made/make suck.Except if they are making them,for third party ,
with quality standards set by another ( Western ) company.
That is another -long - story ...

Let us focus to what they sell ....

In order to make profit ,they cut down expenses in led manufacturing procedures ...

Plastic is cheaper than ceramic .
But case is way bulkier,thermal resistance ( R &#952; )increases ,chip is further away from led base,etc,etc..

Volume emmiter chips need simpler technology and equipment to make .
Easier to make them led devices,than smaller ceramic ones .
(Oslon leds fit completely under the lens of the 8mm led ! )

But the biggest cost is ..phosphors ...
And volume emmiters need much more phosphor material than thin film layer dies ...
Way much more...Ten times more material...
The most expensive raw material in led manufacturing ....

So they make their PC white leds ( PC: Phosphor Conversion ),with cutting down the amount of phosphor material in mind ...

In what ways exactly?
And how that affects the selection of the right leds ,to be used in a grow light ?

Now things start to get interesting and weird .. ...

As was mentioned before ,our beloved plant grows way better when she eats the "whole meal"...
So to overcome several difficulties and severe obstacles,white leds should/could be used in order to have
a trully operational led light ..For our purposes ,at least....Able to grow rich thick flowers ....

Let us start then from the PC white leds ....

The cheapo eastern ones ...
The 'tech' ( guh-guh-guh...) behind them ....

As there is no binning (you think so ? Ha..... You're wrong .... ) in those leds ...
We'll have to 'categorize' them in three categories ...

Cool -Neutral- Warm whites .....

So how exactly they are made and how that affects the purpose of use ?


oh $h...
Now I'm bored to continue...
Give me a moment to roll one ...

To be continued shortly ...

What do you want "them" to do with all those generic encapsulated leds then..............how many traffic lights are left to retrofit??? lol

yeah, my big concern is growers buying these crappy floodlights (630/640/660nm) and expecting them to accurately emit a certain wavelength=====problem

PSUAGRO. said:

What do you want "them" to do with all those generic encapsulated leds then..............how many traffic lights are left to retrofit??? lol

yeah, my big concern is growers buying these crappy floodlights (630/640/660nm) and expecting them to accurately emit a certain wavelength=====problem

Click to expand...

Well ,that concern of yours,brother ,is not of a great importance really.
Mj loves diversity...She really likes all the red wls given to her...
Specially while flowering ...
I'll get (soon I hope ) to the real concerns regarding monochromatics...

subscribed...some peeps have good runs with Vipars and they are cheapys?

stardustsailor said:

Well ,that concern of yours,brother ,is not of a great importance really.
Mj loves diversity...She really likes all the red wls given to her...
Specially while flowering ...
I'll get (soon I hope ) to the real concerns regarding monochromatics...

Click to expand...

True...............but if your specifically targeting 640/660nm===chl a&b peaks for best efficacy/per watt===== or we go back to eastern methods of brute force

Cool Whites :
At average -most oftenly - those are made by using a 465-475 nm blue chip...(that's where they DO their binning ...I'll explain further )
and a YAG yellow phosphor ( with peak at lower yellow wl range ,usually at 560-580 nm )..

They make cool whites with two things in mind : 1) Brightness and 2) Least amount of phosphor needed .

Caution: I mentioned 'brightness' and not "radiance' ...
They need to juice out as many lumens as possible ,with the least amount of phosphor needed ,in order to make a blue chip emit cool white light ....

Hmm..
So they bin out and select the 465-475 blue chips from the rest ....Why ...
For two reasons ...They are the most electrically efficient and those wls are appear brighter to human eye as being closer to the 555nm green peak of human eye
sensitivity....The 465-475 appear brighter than the 430-440 nm blue ones to the human eye,at the same radiant power.

Ok ..Half part of the problem is solved..
They use longer wl blue for making cool white PC leds.

The crucial part ...The phosphor...

How to use the least amount of phosphor and still have a bright cool white led and not a blue one ?
Oh that is easy ,also....A close to green ,yellow phosphor...
being closer to green is appears brighter to human eyes and has the minimal losses of excitation as also minimal losses of phosphor re-excitation ...

(* a photon of 470 nm ,excites a molecule of YAG phosphor,which then emits a photon at i.e. 550 nm ,which excites again another molecule of phosphor,which
then emits a longer wls photon of i.e. 600 nm ,and so on ...The wider the phosphor conversion curve ,the bigger the losses from phosphor re-excitation .
Yag yellow phosphors are relatively narrow-banded regarding their emission range..So they do not have great losses from re-excitation)

At average Cool whites : 20-30% of radiant power falls in the blue 400-500 nm wls
(depending on chip age,driving current,chip temperature,phosphor aging and consistency ,etc).
~50% +/- 5% power in 500-600 nm green range ..
And 20-30% in the 600-750 nm range.

Peak at blue at average is at 465-475 nm ..
Secondary lower peak at 560-580 nm ...

Logically one should think that CW leds are ideal for providing the needed blue wls ...

Well ..No !
Not these ones .
Not for mj.
For corals or carnivorous plants or I do not know for what else ,they might fit in the scene...
In mj's light,those eastern CW do not fit .... Why ?

1) Not that 'ideal ' blue peak. 465-475 is not as strongly photomorphogenic as lower wls.
Neither is the most photosynthetically active blue wls range ...

2) Cause of 20-30% of power in blue ,fewer pieces of CW should be used than say NW ...
That will cause trouble at vegging with light distributing not evenly,and at flowering ,specially towards the end ,
where maturing trichomes could be -prematurely-fried (brown) under the stong blue wls of the few and dispersed CW leds...

3) As led ages ,phosphor ages too...The blue wls start to increase in power over the rest ....

Are NW leds better for providing the blue wls ,when using those cheap leds ?

Very interesting, class is in session.

That would fall in line with my white china led experiment...didn't veg or flower well. Almost gave up on white after that..lucky I didn't.