The "Autos Dias" Project.

Lot's of info ..
Don't know actually from where to start from ....


Ok ...
I 'll give it a shot ....

Most of you ,are already aware of this:
lecture05_physiological_ecology_to_upload1328657595220.jpg


For Cannabis Sativa L. species LSP is 1500umol/sec...

Yes...Ok ...
May I pose a question,please ?

For how long ?
For 1 sec ? For 1 hour ? For 12 hours ? for 18 hours ?
........
The answer is so complicated it almost can not be given .
(Theoritically,at least ) ..
There's a lot of things that have to be taken under consideration ...
Light protecting pigment biosynthesis and accumulation ,degradation of protein D1 thus declining efficiency of Photosystem II ,cell vacuole Nitrogen( in form of NO3- ) availability and replenishing and many-many more ...
Monitoring a real life experiment ,can give some clues ...
Monitor= watch ,check .

Leaf angle is a good indicator ...(the angle between main stem where leaf is attached to and adaxial lamina surface .
Adaxial.jpg


A 40° angle means leaf is 'raised'...Like "praying" ..
A 80° angle means that leaf is almost horizontal.(parallel to ground )

Effects of Variation in Canopy Architecture.jpeg

If you're more interested do some search.
Lot's more if you search ,and the more you keep searching the more it will get complicated ...

vs 1.JPG

So,why instead of driving stable at 1400mA ,having two (example) DND cycles per hour ?

The total difference in amount of energy supplied to the plant(s) is quite small ...
(Roughly and linearly calculated with a max of 297 umols/sec at 2200mA )
~3000 moles /per hour more , are supplied with the 2x DND cycles ..
~36.000 more umoles per 12 hour regime ....That is 0.833 umoles/sec difference ..
Although trend line value is 1368 mA for the DND way of driving ...

The real difference is inside the plant cells ...
That are made of proteins and carbonhydrates and not from
steel or duraluminium ...
The ones oftenly needing "breaks" -in form of clouds passing by ,cloudy days ,shade from other plants vs sunlight angle ,etc- and not fresh oil or new batteries ...

Yes...The amount of energy* ,the quantity of quanta is the most crucial factor ,regarding indoor cultivation of ..sun-adapted and light-needy ..weeds...guh ..

*(E=Power x Time )

But it plays an also crucial role How this energy is " supplied " ...

Regarding the quantity of Power (umol/sec) and it's quality :

The spectrum . The "Spectral Power distribution per wavelength "

&
Regarding quantity of Time (hours ) and the quality :
Of power distribution vs time (stable / DND / other ).
The so neglected " time -spectrum " .


Cheers.
 
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Another interesting issue is the " pulsating light " .....

Pulsating light at frequency range of 0.1 -1 Hz has shown an increased photosynthesis efficiency ( ~65 %@ 750 umol/sec ) of PS II ( Ch B ) ,as opposed to continuous light ( ~55 % @ 750 umol/sec ).....

Now ...Add to this the cooling advantage of pulsating diodes and the energy economy ( 50% less energy )...


http://www.academia.edu/3243327/Intelligent_lighting_system_for_plant_growth_and_development
 
Last edited:
Hmmm...
My 'neighbours' are doing a very similar research .....

http://www.uni-obuda.hu/journal/Senol_Tasdelen_52.pdf

" In the study,a DC constant supply condition was considered. As for the ongoing
designs, new growth units are worked on to examine two different working
conditions simultaneously. The upcoming studies will discuss the experiments
conducted with existing control card and control mechanism on the plants that are
tested by one LED plant growth unit with PWM output and by another LED plant
growth unit with constant DC supply. Thus, the development process and crop
yield of the plants which are grown in PWM mode and with DC constant supply
will be examined.Finally, the effect of different PWM parameters on plants will
be studied.
"

 
Photosynthesis under Artificial light
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by Bianey Medina on 29 April 2014 26
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Transcript of Photosynthesis under Artificial light
Photosynthesis in the light of future advances
In the future LED lights will increase the productivity and quality of fruit and vegetables. These LED lights are also energy-efficient and will help feed the growing human population.

Photosynthesis under Artificial light
the shift in primary and secondary metabolism
Artificial light for photosynthesis
Provides plants with energy and information that they require for development
Why are LED Lights Beneficial?
By using LED lights the idea of growing plants under natural light can be mimicked, by mixing colors together.
Red, blue and Green LED lights make a perfect combination. Complimenting the blue and red light combination with a 24% of green light can enhance growth in some plants.
High LED triggers production of secondary compounds
Although more research is needed light irradiance may have a negative effect on secondary metabolite production, flavonoids and phenolics.
Modification of the metabolism through supplemental monochromatic lighting
Red and blue light increase the antioxidant content of vegetables, but reduced with white LED lights. This will impact the taste in some foods, for example in tomatoes two compounds that increased are involved with the degree of sweetness making them sweeter
Introduction
Due to numerous factors (climate change, land use competition, etc) people started to turn to artificial growing systems. However, artificial growing systems require some form of additional light sources in order for plants to grow. LEDs were developed - they were required to be compatible with the photosynthesis and light-signaling requirements of plants: wavelength and fluence.
types of artificial lighting available for growing plants
LEDs ability to mimic natural light
potential for manipulating the plants metabolism
Covering
hid lights
fluorescent lights
LED lights
but....
fluorescent lights are not stable over a long period of time
require additional light sources to help maintain the photon fluence necessary for high productivity
but...
Can't be placed near the plants because they have a high operating temperature
Can effect the spectral distribution due to a change of input of power
limits their use and innovation
Lettuce and Red LED Lights
Lettuce that was grown under a red LED light showed primary embryo leaves that were larger than normal. This phenomenon known as phytochrome-dependent. This is fixed by growing the lettuce under both a red and blue LED light.
Chloroplast differentiation and de-differentiation
In the absence of light plants develop etiolation symptoms.
“When the plants are exposed to light, chloroplast differentiation involves the accumulation of proteins, lipids and photosynthetic pigments”
beneficial because
high fluence
high photosynthetically active radiations
HID lights are used in greenhouses and plant growth rooms
beneficial because
fluorescent lights enhance blue and red spectra
fluorescent lights are used in growth rooms
Predicted to replace fluorescent and HID lamps in garden cultivation and management, it will revolutionize controlled growth environments
beneficial because
LEDs are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness.
can use pulse lighting
LED LIGHTS
White LED lights present a lag phase in the Chlorophyll accumulation, but that is eliminated with using blue LED lights.

Light intensity is also important in Chlorophyll synthesis.
A high intensity red LED light showed an accumulation of Chlorophyll, but was fixed with a blue LED light.
Adding red LED lights to a plant can be more
stressfulthan a blue LED light. “Much more investigation is needed to understand the impact of LED light on primary and secondary metabolism of photosynthetic organisms.”
LEDs are highly efficient because they have a low operating temperature and they are small in size which allows them to be placed close to leaves

LEDs can affect the fluence and wavelength requirements of plants and at the same time they can allow for a specific wavelength to be enriched (can supply the light quantity and quality required for different phases of growth).
Plants are mostly immobile, therefore they have to adapt to their environment

Plants sense their environment through different receptors - such as photoreceptors
The pigment portion of the photoreceptor allows it to extract from the natural white light the specific information of light constraints in its environment.
If lighting is weak then photosynthesis cannot work and etiolation symptoms appear
If light is excessive it generates oxygen radicals and causes photoinhibition
Both limit primary productivity


https://prezi.com/zb3nyaei4dd8/photosynthesis-under-artificial-light/
 
@stardustsailor

If your right about your assumption(s), the proposed outcome(s) would be phenomenal for us indoor growers and our plants.

Despite your remarkable, coherent grammar and ability to break apart cited information into digestible tid bits, much of what this thread (and some of your other threads) offers is beyond the scope of what is commonly understood by the majority of us here on RIU.

Regardless of this, I'm eager to see what the data from your experiments bring you as all of us here could handle a few extra grams and/or ounces, as well as cheaper electricity bills.

And what true lover of wisdom could overlook the knowledge to be had?

;-)
 
stardustsailor said:
Another interesting issue is the " pulsating light " .....

Pulsating light at frequency range of 0.1 -1 Hz has shown an increased photosynthesis efficiency ( ~65 %@ 750 umol/sec ) of PS II ( Ch B ) ,as opposed to continuous light ( ~55 % @ 750 umol/sec ).....

Now ...Add to this the cooling advantage of pulsating diodes and the energy economy ( 50% less energy )...


http://www.academia.edu/3243327/Intelligent_lighting_system_for_plant_growth_and_development
Click to expand...

Will This Gizmo beable to pulse @ .1 to 1Hz ? Almost have everything to build one. Just need the dip switch I believe.
 
People in 2005 were pulsing their traffic light grow lamps quoting some scientific studies about how pulsed light improves photosynthesis. I think that has as much truth to it as putting a rusty nail through the trunk will increase yields. Over the years, the results have lead me to conclude that only average power output matters, not pulsed output.

They also had this bizarre idea that R+B leds would grow better than warm white. Turns out that's only true for lettuce and leafy greens.
 
Meanwell driver data sheet has the frequency range of 100Hz to 3KHz. Not sure if those are the limits or just a suggestion. Below a 100Hz at some point you will see the flickering.
Captur7_zpsf0bf2877.png

reading threw PDF you posted the 1Hz did the best But the 100Hz was slightly better then constant on, I would still take that power savings though. So even if the bottom limit on the driver is 100Hz Should be worth while to slap it in my light.
 
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I did mean to use an existing 555 package obviously.

http://www.amazon.com/NE555P-555-generating-accurate-oscillation/dp/B00CL7IV7E
http://www.amazon.com/Pcs-2-54mm-Pitch-Sockets-Adaptor/dp/B005UV0964/

(I ordered that a few months ago for prototype projects)

I was going to use one for my 730nm "pulse after lights go out" timer machine.

stardustsailor said:
Yes .Or use that simple LM555 (timer IC ) ....
Just make sure that VCC @ Pin 8 of the 555 is + 10 VDC (+/- 500mV )

http://www.bowdenshobbycircuits.info/555.htm
Click to expand...
 
Last edited:
churchhaze said:
People in 2005 were pulsing their traffic light grow lamps quoting some scientific studies about how pulsed light improves photosynthesis. I think that has as much truth to it as putting a rusty nail through the trunk will increase yields. Over the years, the results have lead me to conclude that only average power output matters, not pulsed output.

They also had this bizarre idea that R+B leds would grow better than warm white. Turns out that's only true for lettuce and leafy greens.
Click to expand...

And many more ....
http://thebirdman.org/Index/Others/...lantGrowthWithElectricity&Magnetism&Sound.htm

Thing is that some of them ,really did show some significantly " weird " results ,when science did bother to do some
experiments ....
Like magnets or electricity applied
 
JavaCo said:
Meanwell driver data sheet has the frequency range of 100Hz to 3KHz. Not sure if those are the limits or just a suggestion. Below a 100Hz at some point you will see the flickering.
Captur7_zpsf0bf2877.png

reading threw PDF you posted the 1Hz did the best But the 100Hz was slightly better then constant on, I would still take that power savings though. So even if the bottom limit on the driver is 100Hz Should be worth while to slap it in my light.
Click to expand...

The flickering is noticeable already at 500 Hz ..
At least I was able to "notice" it ..
(Gave me a good headache I think ,as I was working with the VEROS flashing nearby ,for quite some time ..)

For "flicker-less " output ,PWM frequency should be ,AT LEAST ~ 1KHz.

Still,100 Hz flickering is pretty much far from being 1 Hz flashing ..
 
You didnt by any chance take it lower then a 100Hz did you. Just wondering what would happen to a meanwell if you ran the frequency lower then specs
 
1khz is usually where i start pulsing 7-segment arrays and dot matrix arrays to make them look solid.

500khz will work in a pinch.

I've been using the arduino with a cmos 8 bit shift register and a 2to4 binary decoder to light up 4x7seg displays using only 4 wires. (not including power and ground).

The con of this (the reason I'm bringing it up) is that if you try to scan between the 4x7seg displays faster than 1khz, you start noticing the shift registers (if unlatched) shifting in each 7xseg. If you lower the scan frequency, it's hardly noticeable, but then you see the segments themselves changing.

The balance there was around 700hz to prevent the fuzz caused by shifting in without output enable (latches). A better solution, of course, would be to get output latched shift registers.
 
I've just noticed something ......

(..)Photosynthesis can be increased up to 400% by means of intermittent light. The researchers used a rotating disk with a cut-out section to chop the light from a lamp. They found that 75% of the light from a given source could be blocked without decreasing the rate of photosynthesis. The improved yields produced by intermittent light depends on the frequency of the flashing. A frequency of 4 flashes/minute resulted in 100% increased yields. The amount of work done by the light can be increased by shortening both the light and dark periods. For example, yields can be increased 100% by using 133 flashes/second. Emerson and Williams improved the yield (compared to continuous light) by 400% by using only 50 flashes/second. The light flashes must be much shorter than the dark period. The minimum dark period is about 0.03 at 25o C. The light reaction begins with about 0.001 second/flash, and it depends on the concentration of carbon dioxide.(...)

http://thebirdman.org/Index/Others/...lantGrowthWithElectricity&Magnetism&Sound.htm
------------------------------------------------------------------------------------------------------------------------------------
(..)To evaluate the ILSys performance, an experiment was carried out to analyze the effects of pulsed light at different frequencies in tomato plants. According to the experimental analysis, thes ystem had an excellent behavior. It showed that at some fre-quencies (0.1Hz, 1Hz and 50Hz) there were a significant increase in the photochemical efficiency of Photosystem II( uPSII) and electron transport rate (ETR) compared to the continuous light.(...)

http://www.academia.edu/3243327/Intelligent_lighting_system_for_plant_growth_and_development



50 Hz pulsed light ...
Analog HID E/M ballasts (Cu/Fe ),
do switch the HPS bulb on/off at 50 Hz fequency (here in EU ) ..
W-e-i-r-d ,at least ....
 
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churchhaze said:
It's interesting, but I'll have to see it before I believe it.
Click to expand...
Me too ...
I've to see it first, with my very own eyes and then I might do some further research about it...
:P
Maybe on a next "round" ,'pulsating' COBS will have their chance ...
I'm kinda curious to test two pulse frequencies ... 1 Hz and 50 Hz ..
For the moment being ,Dawn-Noon-Dusk "power vs time - spectra" , is being under evaluation ..
 
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