V series "Tetras"

Doer

Well-Known Member
No worries,Salm..
Today's Saturday ,outside is raining ,my girlfriend (yes) she's lightly snoring (!) at the couch
(too many joints,she had ,as always)..
And I've made myself a cup of a weird tea mix I've found (probably from an ex,so far beyond it;s expiring date ... )..
It smells good and fruity ,though ..
And just lit up a big fat joint full of my favourite White Russian and some Karelias tobacco ..
No ,i do not feel sad or the least guilty about my lungs ...
They do not deserve such treat -i know all about it- ,but the rest of me ,does really..

Anyway ..
Some post mid-night saturday fever's thoughts....


-The more I work with the Vero 29 arrays ,the more I fall in love with them ...
I mean ,they just need four M3 screws to be securely attached to a heatsink .
The contact force achieved is high enough .No horrible spring-action holders !
Cooling them is another issue ,that is almost jaw dropping .
Ok they have 156 dies under a 29 mm Dia. LES ,so of quite low density ,a COB array ...
Nevertheless ,the aluminium substrate is rigid and durable enough ,while it posses a high thermal conductivity.
Thus the 0.11-0.13 C/W thermal resistance from junction to case ...
Amazing COB ...A "noble monster" ...A "kind giant " ...

Haven't actually measured with a lux meter ,but to my eyes the difference in brightness ,
between a VERO 29 and a CXA3070 Z4 bin @ 2200 mA ,is quite noticeable.Maybe more than that .
The Vero 29 really seems to be outputting much more light ...And ,trust me ,it's not just me saying that ,is plenty of people
,close friends and relatives ,suggesting same,when witnessing the comparison ...


-Anyway.Change of subject.

Joint's side -effects you see...

BTW ..

"Lux meter "...

Is it just stupid me or if one has digitised the relative spectral power distribution graph of a LED or COB ,into y values /nm and have them further "analysed" in a spreadsheet then .....
Then ...

If one uses a lux meter or similar ,but not a PAR meter ...
If the units measured by the hand-held equipment are lumens or lux (lumens/m^2 )
Then ...

If really that hand held measuring device's sensor is CIE1924 Photopic V(λ) calibrated ..
One can transform the readings ,via the spreadsheet ,into Watts ,W/m^2o, umol/sec or umol/sec/m^2 ..
With quite good precision ..

And correct me if I'm wrong ...
PAR meters are way much more expensive( ten fold the price ? ) than Lux meters ,ain't so ?
Hmmm...

How come ,I haven't thought that before ?
A good luxometer ...Photographers' equipment and parafernalia then ....

https://www.trotec24.com/en-de/measuring-instruments/emission/bf06-lux-meter.html?gclid=CNvVjuCqq8MCFWPmwgodRxsAkQ
I just got a dandy lux meter for iPhone. It is the most expensive app I've ever bought.
$8.00 !! :)

What it does is pretty trick, but you tell it everything up front. Type of light source, LED, sunlight, etc. Stated watts, distance from measuring surface and the angle of view for your camera. There are a dozen sources to choose. And it has a digitized
SPD graph with total color temperature read out.

It works with the camera settings and knows about the lens and CCD, etc to calculate the compensations.

It works off a white card reading you take a photo of. It lacks totally accuracy like they all do, if under $5000 USD. But, for compares of distance and color, it seems pretty good.
 

Doer

Well-Known Member
And some quick notes & observations ,
regarding the spectrum of emitted light from Vero 29 versus CXA 3070,
both @ 3000K 80Ra .


.................................................................

1) The PPF percent distribution of the two COBs,for the range 380-780 nm is as follows
( BL 380-499 nm - GR 500-599 nm - R 600-699 nm -FR 700-780 nm ) :

Vero 29 3K80Ra : 10.67% - 40.73% - 44.04% - 4.57% LER: 320-322 ( typ:321 )
CXA3070
3K80Ra :10.62% - 41.37% - 43.71% - 4.3% LER: 324-326 ( typ:325 )

And their PPF spectral distribution graph in comparison (Both @ 2200 mA & Tc=50C ).
View attachment 3374197

The differences seem rather minuscule..Ain't so ?

Well ...
Those of you that have both of these COBs try a small test ...
Illuminate firstly a mj plant with one of the two COBs.
Try to record in your mind ,the actual green shade of the leaves reaching your eyes ...
Then illuminate the same plant with the other COB ..
What do you see ?
The difference of the green hue from the leaves is not minuscule,but rather great ,this time ....

(Under the CXA3070 the photosynthesizing leaf tissue has a yellowish-lime green hue,
while under the Vero 29 the same photosynthesizing leaf tissue has a dark green -purplish hue ! )

What assumptions we can make out of that ?

Well ...For starters ,the photosynthesizing leaf tissue is NOT GREEN ,actually ...
It's just the fact that our vision that " translates" the reflected light into "green " ....
Human vision ,in well lit situations ,is most sensitive to green 555 nm light (Photopic )

But human vision can not perceive as "light" E/M radiation over ~780 nm ..
(Although some people are able to see up to ~800 nm )

But what wls plants do reflect actually ?
Well ..Let's see our beloved plant...
View attachment 3374212
(Vegetative Growth phase )


View attachment 3374209
(checkout the green curve :Leaf Lamina Absorptance - of alive tissue and not some kind of diluted Chlorophyll )



15 % reflection of green ....Actually peaking close to..555 nm !!!
Still over 50% reflection is taking place over ~740 nm ...
So ,actually photosynthesizing leaf tissue ,would had a rather brownish /reddish hue,
if only ,we humans could perceive the NIR /FR E/M radiation as light being able to see the " whole picture".
But we can't ...
So ,due to limited range of E/M radiation perceived as light by human vision and
due to it's high sensitivity to green light ,plants seem to be green ..


Well..They are not green .

So next time one will say to you that green light is reflected and not absorbed ,
just laugh . It's a good ol' joke !


2) Both of these COBs can be used for vegging with great results .

Just do not place them near the plant tops,'cause your plant(s) will stay extremely compact (short ) ...
And that will have a negative impact on yield ..(Trust me,on that one ) .
Later in flowering ,COBs and plant(s) can have a smaller distance between them .
No need for extra monochromatic LEDs .Just give raw power (more COBs ) if you want bigger yields.
Nothing more is needed .

Cheers.
:peace:
OMG!!! That's it! Of course. The human eye is evolved so that it detects the slightest movement, even a subtle change of shade. It is evolved to see the most shades from the most dangerous area, the foliage.

So, although the plant is not actually and technically reflecting green, the brain chooses green to see, for fine grain survival.

And why green? Green is easiest to "see" after blue is filtered. What filters the blue?
Water in the eyeball. So, that is why there is not some clear oil filling the eye.

Oil doesn't filter the blue and let those green shades pop, so we can zig or zag.

Nature. And I have been wondering about all this in the back of my mind for years.

Thank you!
 

AquariusPanta

Well-Known Member
OMG!!! That's it! Of course. The human eye is evolved so that it detects the slightest movement, even a subtle change of shade. It is evolved to see the most shades from the most dangerous area, the foliage.

So, although the plant is not actually and technically reflecting green, the brain chooses green to see, for fine grain survival.

And why green? Green is easiest to "see" after blue is filtered. What filters the blue?
Water in the eyeball. So, that is why there is not some clear oil filling the eye.

Oil doesn't filter the blue and let those green shades pop, so we can zig or zag.

Nature. And I have been wondering about all this in the back of my mind for years.

Thank you!
Thank the Yodamaster!!

;-)
 

guod

Well-Known Member
OMG!!!

And why green? Green is easiest to "see" after blue is filtered. What filters the blue?
Water in the eyeball.
So, that is why there is not some clear oil filling the eye.

Oil doesn't filter the blue and let those green shades pop, so we can zig or zag.

Nature. And I have been wondering about all this in the back of my mind for years.

Thank you!
longer wavelength(Red)filtered by water...not blue
Transparency of Water in the Visible Range
 

Doer

Well-Known Member
The blue is "reflected" and excluded somewhat, by water which absorbs and passes reds, not blues. That is, the water filters the Blue and passes the Red.
But, this is about Green. And of course the deeper you go the more light is absorbed, not filtered.

Reds are absorbed rather quickly. But this is about the eyeball. And the absorption distance for red is non-existent, practically. Just a cm or so to the back of the eye.
 
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Doer

Well-Known Member
Just a cm ,is enough ,to absorb plenty of red photons.

Cheers.
:peace:
And just enough time for our brain to say, meh, whatever. I'm just making it all up for survival anyway. :)

I've read where the brain's "reality" is a mental model that is a full 100 miliseconds in the future. Our brain is constantly refining this model as events proceed.

It is the basis for our Zig vs Zag decisions, and everything else.
 
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stardustsailor

Well-Known Member
Asking for Guod's assistance

Dear brother Guod ,in case you notice that post , I'm on the need of your technical experties,once again.
But first let me make a small introduction to the issue :

Here is a pdf from NASA :

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19960011687.pdf


And here is the excerpts of interest from it ,being the "introduction "
(pages noted are not from the paper itself ,but from Adobe Reader paging ) :

page 19/412 :
Time course of diurnal PPF and integrated diurnal irradiance, combinations of irradiance and
duration, have important effects on photosynthetic carbon metabolism and its regulation.
Of particular importance is the rapidity with which the light begins.
Maximum irradiance level and nthe duration of high irradiance are
important aspects of the time course of diurnal PPF,potentially affecting the degree of
photoinhibition or photoprotection, both of which can lower the efficiency of light use for photosynthesis.
It is important that these aspects of irradiance generally be similar to those under which the plant developed
.

page23/412:
Evolution of photosynthesizing organisms under cyclic diurnal irradiance has equipped
plants to regulate the photosynthetic process in ways that allow carbon to be assimilated
efficiently over the wide range of diurnal cycle irradiance. A particularly important aspect of
this diurnal time course is the fact that irradiance begins slowly, generally matching the time
constants of processes related to photosynthesis. For instance stomata1 opening and induction of
photosynthetic carbon assimilation by the Calvin cycle generally have time constants on the
order of minutes. Induction of photosynthesis involves building the concentration of metabolite
pools and enzyme activities associated with photosynthetic carbon assimilation. Beginning a
photoperiod with rapid, practically instantaneous irradiance can lead to light and water stress

(Geiger et al. 1994).

page26/412:
Consequences of Rapidly Initiated or Gradually Changing Irradiance

Depending upon initial conditions and the path taken to reach stability, different regulatory
elements may assume different degrees of importance. This metabolic flexibility is a result of
probabilistic behavior during regulation, in which the path taken to reach stability cannot be
described by a unique mathematical solution. The general pattern of response will be
conditioned by a number of factors, such as the immediate past history of the plant. This point is
well illustrated by observing the response of carbon assimilation in leaves of a sugar beet plant to
two different light regimes on successive days. Depending upon how fast illumination reached a

maximum at the beginning of the day, different combinations of activation states and associated
levels of metabolites were observed for the three enzymes of the assimilatory segment

(Servaites et al., 199 1 ; Geiger et al., 199 1). Although the leaf maintained similar maximal
midday photosynthesis rates under the different light regimes (Figure 7), considerable
differences in the degree of Rubisco and PRK activation (Figure 8) and the levels of RuBP and

PGA (Figure 9) were observed. Under the gradually increasing light of a diurnal light regime,

page27/412:
the midday level of Rubisco activation state was nearly 100% and the RuBP level was about
twice Rubisco binding site level. By contrast, when light increased to a maximum rapidly, as
often occurs under growth room conditions, the midday level of Rubisco activation state was
maintained at only 60% throughout the day, while the RuBP level was nearly twice that observed

in the same leaves under gradually increasing light. Regulation by light-mediated enzyme
activation was favored under gradually increasing irradiance while metabolite-mediated
mechanisms were relatively more important when irradiance increased rapidly. The different
forms of regulation achieved similar photosynthesis rates through different combinations of
activation states and metabolite levels, an expression of the metabolic flexibility of
photosynthesis. As a consequence of the physiological state resulting from metabolic flexibility
in regulatory responses, plants may respond differently to stress. The response of photosynthesis

to application of glyphosate depends on whether the day began with rapidly initiated irradiance
or under gradually changing irradiance (Figure 10). When irradiance was begun rapidly at the
start of the day, RuBP level was high, Rubisco activation state was only about 70% (Figure 10
A-C). Under these conditions, inhibition of photosynthesis does not occur until about 4 h after
glyphosate is applied, when RuBP level has fallen to a point where its level begins to be a

significant factor determining photosynthesis rate (Servaites et al., 1987).

page28/412:
When the photoperiod begins
with rapid'onset of high light carbon allocation is changed markedly. Under these conditions,
sucrose is synthesized from newly fixed carbon by two biochemical pathways and no starch is

produced for several hours. Similarly, if irradiance remains high at the end of the day starch
synthesis stops and sucrose synthesis and export nearly double. Clearly, carbon metabolism is
changed by departure from the usual daily time course of irradiance. As a result of metabolic
flexibility the plant acclimates to the step time course of irradiance often used in growth under
artificial light but the metabolic state of the plants are changed.


And now ,on to the main issue ...

As you may have understand already ,the main issue is the building of an electronic circuit ,
that will gradually increase irradiance to the pre-selected level .

And here are the allowances & limitations of it :

-The circuit will be powered from the Meanwell PS-05-12 power supply that powers the fan.
So ,once the timer switches ON the fixture ,there is a power source available of 12 VDC and with available current of ~ 250 mA . (~200 mA are used for the fan ) .So the circuit has to dissipate 3 or less Watts.

-The pre-selected irradiation level is achieved via resistors ,as you probably already know.
So PWM or Voltage dimming are not desirable..

-Also not desirable is the use of any kind of MCU / PLC unit or any digital potentiometer IC .
To keep overall cost relatively low ,analog electronic components are most preferable.
MOSFETS,transistors,thermistors,varistors,ICs like 555 timers - 4017 decade counters -etc are
most desirable.

- It would be nice if that circuit had adjustable " rise time " feature up to 30 minutes ,
as also a minimum resistance adjust ( low level threshold ) .

So ,in other words the wished circuit is a circuit that will be powered once the timer switches ON
the LED light fixture ,it will have a (adjustable) minimum resistance (range : 2K5 to 10K ) and via an
adjustable "rise time" ( range: 0-30 minutes) it will reach the pre-selected resistance (selected by fixture's
rotary switch ) .And then the circuit may remain powered ,but at an "inactive" state.Once the
timer switches OFF the LED light fixture (along with the desirable circuit) ,the circuit will "reset" to be once again active ,when the LED light fixture will be switched ON again ,the next day .

I'm breaking my head to design such a circuit with a 555 timer ,a 4017 decade counter and few transistors.
But it seems that I'm not actually managing it ...
:wall::wall::wall::wall::wall:

Any ideas,please ?

Cheers.
:peace:
 
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nogod_

Well-Known Member
Plant doesnt like full power for 12 hours and will respond better to less power ...
My wallet likes this theory...

:clap:

Is a continuous, gradual increase in intensity really necessary or can you achieve the same effect with 30 mins of a low-power "wakeup" string followed by your main full power strings?

Good find!

Asking for Guod's assistance

Dear brother Guod ,in case you notice that post , I'm on the need of your technical experties,once again.
But first let me make a small introduction to the issue :

Here is a pdf from NASA :

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19960011687.pdf


And here is the excerpts of interest from it ,being the "introduction "
(pages noted are not from the paper itself ,but from Adobe Reader paging ) :

page 19/412 :
Time course of diurnal PPF and integrated diurnal irradiance, combinations of irradiance and
duration, have important effects on photosynthetic carbon metabolism and its regulation.
Of particular importance is the rapidity with which the light begins.
Maximum irradiance level and nthe duration of high irradiance are
important aspects of the time course of diurnal PPF,potentially affecting the degree of
photoinhibition or photoprotection, both of which can lower the efficiency of light use for photosynthesis.
It is important that these aspects of irradiance generally be similar to those under which the plant developed
.

page23/412:
Evolution of photosynthesizing organisms under cyclic diurnal irradiance has equipped
plants to regulate the photosynthetic process in ways that allow carbon to be assimilated
efficiently over the wide range of diurnal cycle irradiance. A particularly important aspect of
this diurnal time course is the fact that irradiance begins slowly, generally matching the time
constants of processes related to photosynthesis. For instance stomata1 opening and induction of
photosynthetic carbon assimilation by the Calvin cycle generally have time constants on the
order of minutes. Induction of photosynthesis involves building the concentration of metabolite
pools and enzyme activities associated with photosynthetic carbon assimilation. Beginning a
photoperiod with rapid, practically instantaneous irradiance can lead to light and water stress

(Geiger et al. 1994).

page26/412:
Consequences of Rapidly Initiated or Gradually Changing Irradiance

Depending upon initial conditions and the path taken to reach stability, different regulatory
elements may assume different degrees of importance. This metabolic flexibility is a result of
probabilistic behavior during regulation, in which the path taken to reach stability cannot be
described by a unique mathematical solution. The general pattern of response will be
conditioned by a number of factors, such as the immediate past history of the plant. This point is
well illustrated by observing the response of carbon assimilation in leaves of a sugar beet plant to
two different light regimes on successive days. Depending upon how fast illumination reached a

maximum at the beginning of the day, different combinations of activation states and associated
levels of metabolites were observed for the three enzymes of the assimilatory segment

(Servaites et al., 199 1 ; Geiger et al., 199 1). Although the leaf maintained similar maximal
midday photosynthesis rates under the different light regimes (Figure 7), considerable
differences in the degree of Rubisco and PRK activation (Figure 8) and the levels of RuBP and

PGA (Figure 9) were observed. Under the gradually increasing light of a diurnal light regime,

page27/412:
the midday level of Rubisco activation state was nearly 100% and the RuBP level was about
twice Rubisco binding site level. By contrast, when light increased to a maximum rapidly, as
often occurs under growth room conditions, the midday level of Rubisco activation state was
maintained at only 60% throughout the day, while the RuBP level was nearly twice that observed

in the same leaves under gradually increasing light. Regulation by light-mediated enzyme
activation was favored under gradually increasing irradiance while metabolite-mediated
mechanisms were relatively more important when irradiance increased rapidly. The different
forms of regulation achieved similar photosynthesis rates through different combinations of
activation states and metabolite levels, an expression of the metabolic flexibility of
photosynthesis. As a consequence of the physiological state resulting from metabolic flexibility
in regulatory responses, plants may respond differently to stress. The response of photosynthesis

to application of glyphosate depends on whether the day began with rapidly initiated irradiance
or under gradually changing irradiance (Figure 10). When irradiance was begun rapidly at the
start of the day, RuBP level was high, Rubisco activation state was only about 70% (Figure 10
A-C). Under these conditions, inhibition of photosynthesis does not occur until about 4 h after
glyphosate is applied, when RuBP level has fallen to a point where its level begins to be a

significant factor determining photosynthesis rate (Servaites et al., 1987).

page28/412:
When the photoperiod begins
with rapid'onset of high light carbon allocation is changed markedly. Under these conditions,
sucrose is synthesized from newly fixed carbon by two biochemical pathways and no starch is

produced for several hours. Similarly, if irradiance remains high at the end of the day starch
synthesis stops and sucrose synthesis and export nearly double. Clearly, carbon metabolism is
changed by departure from the usual daily time course of irradiance. As a result of metabolic
flexibility the plant acclimates to the step time course of irradiance often used in growth under
artificial light but the metabolic state of the plants are changed.


And now ,on to the main issue ...

As you may have understand already ,the main issue is the building of an electronic circuit ,
that will gradually increase irradiance to the pre-selected level .

And here are the allowances & limitations of it :

-The circuit will be powered from the Meanwell PS-05-12 power supply that powers the fan.
So ,once the timer switches ON the fixture ,there is a power source available of 12 VDC and with available current of ~ 250 mA . (~200 mA are used for the fan ) .So the circuit has to dissipate 3 or less Watts.

-The pre-selected irradiation level is achieved via resistors ,as you probably already know.
So PWM or Voltage dimming are not desirable..

-Also not desirable is the use of any kind of MCU / PLC unit or any digital potentiometer IC .
To keep overall cost relatively low ,analog electronic components are most preferable.
MOSFETS,transistors,thermistors,varistors,ICs like 555 timers - 4017 decade counters -etc are
most desirable.

- It would be nice if that circuit had adjustable " rise time " feature up to 30 minutes ,
as also a minimum resistance adjust ( low level threshold ) .

So ,in other words the wished circuit is a circuit that will be powered once the timer switches ON
the LED light fixture ,it will have a (adjustable) minimum resistance (range : 2K5 to 10K ) and via an
adjustable "rise time" ( range: 0-30 minutes) it will reach the pre-selected resistance (selected by fixture's
rotary switch ) .And then the circuit may remain powered ,but at an "inactive" state.Once the
timer switches OFF the LED light fixture (along with the desirable circuit) ,the circuit will "reset" to be once again active ,when the LED light fixture will be switched ON again ,the next day .

I'm breaking my head to design such a circuit with a 555 timer ,a 4017 decade counter and few transistors.
But it seems that I'm not actually managing it ...

Any ideas,please ?

Cheers.
:peace:
 

SomeGuy

Well-Known Member
Plant doesnt like full power for 12 hours and will respond better to less power ...
My wallet likes this theory...

:clap:

Is a continuous, gradual increase in intensity really necessary or can you achieve the same effect with 30 mins of a low-power "wakeup" string followed by your main full power strings?

Good find!
good idea.

gets me thinking about turning on the fixtures on different timers.
 

Doer

Well-Known Member
Well, it seems like tapering off is an important as tapering on. I had wondered about this, as well. Great science in that post. Light carbon vs starch transport? Only 60%??

It seems like a job for arduino. But, I don't get why you can't just tap into the dimming circuit, and have arduino run the dimmer values against its timers.
 

bicit

Well-Known Member
Well, it seems like tapering off is an important as tapering on. I had wondered about this, as well. Great science in that post. Light carbon vs starch transport? Only 60%??

It seems like a job for arduino. But, I don't get why you can't just tap into the dimming circuit, and have arduino run the dimmer values against its timers.
I think he just wants a circuit that does it automatically, without all the extra bells and whistles from the arduino. Presumably so it can be built quickly and cheaply my without having to program. Could be wrong on that.
 

stardustsailor

Well-Known Member
I think he just wants a circuit that does it automatically, without all the extra bells and whistles from the arduino. Presumably so it can be built quickly and cheaply my without having to program. Could be wrong on that.
On the contrary ...:razz:

(...)
-The pre-selected irradiation level is achieved via resistors ,as you probably already know.
So PWM or Voltage dimming are not desirable..

-Also not desirable is the use of any kind of MCU / PLC unit or any digital potentiometer IC .
To keep overall cost relatively low ,analog electronic components are most preferable.

(...)
Cheers.
:peace:
 

Doer

Well-Known Member
On the contrary ...:razz:

(...)
-The pre-selected irradiation level is achieved via resistors ,as you probably already know.
So PWM or Voltage dimming are not desirable..

-Also not desirable is the use of any kind of MCU / PLC unit or any digital potentiometer IC .
To keep overall cost relatively low ,analog electronic components are most preferable.

(...)
Cheers.
:peace:
Not desirable? I see. You want an analog counter. Cascade reset counters that select from a resistor bank?

I see. Let me think about this.
 

bicit

Well-Known Member
On the contrary ...:razz:

(...)
-The pre-selected irradiation level is achieved via resistors ,as you probably already know.
So PWM or Voltage dimming are not desirable..

-Also not desirable is the use of any kind of MCU / PLC unit or any digital potentiometer IC .
To keep overall cost relatively low ,analog electronic components are most preferable.

(...)
Cheers.
:peace:
I wish I knew enough about DC circuitry to assist. I'm actually really interested in what you're proposing.
 

Doer

Well-Known Member
I think he just wants a circuit that does it automatically, without all the extra bells and whistles from the arduino. Presumably so it can be built quickly and cheaply my without having to program. Could be wrong on that.
I've been looking at Tiny and some of the other smaller implementations. I'd like to get to single use sketches. And distribute the compute power. Run some redundancy.

I had Phygets for awhile but weak link there is running it thru Windows. They have Linux versions also. But the UI I was using was Windows and C#.
 
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