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Author Topic: High Efficiency LED for Joule Thief, etc.  (Read 27656 times)

MarkE

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Re: High Efficiency LED for Joule Thief, etc.
« Reply #30 on: August 20, 2015, 05:24:59 PM »
Remember this one TK ?

https://www.youtube.com/watch?v=hvf9Uo7UVx0
It is a mnice demonstration of why AC power must be calculated by mutliplying instantaneous voltage and current.

Magluvin

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Re: High Efficiency LED for Joule Thief, etc.
« Reply #31 on: August 21, 2015, 04:40:40 AM »
Tinsel
A sizzling Topic ATM ...
Think PINK
I am very Happy to see "you" working on this .

https://www.youtube.com/watch?v=ILzWmw53Wwo

http://www.terraspheresystems.com/index.php/news-media/19-news/41-urban-farming-20-no-soil-no-sun
From Above link  I square ft of Vertical farming WILL YIELD 64 head of lettuce per arum, where as 1 square foot of Land farming
?? MAY ??   yield 3 heads per anum.[Ideal conditions]

Establishing Crop yields per square foot against energy required to run the LED's would be wonderful to know ,do they have to run at full power ?
I do understand that PWM would NOT be acceptable for growing crops ,you can trick the eye But not mother nature [thx Brad].
Or would PWM be appropriate for part of the plants 24/7 365 artificial day ??

This is the future.....

Chet K

"I do understand that PWM would NOT be acceptable for growing crops ,you can trick the eye But not mother nature [thx Brad]."

Well that would need to be tested. Remember sliders little circuit that emitted high freq and plants near by grew better. What was it, 27mhz?  Leds should be able to produce that, as I think optical fiber data transmission I believe is much higher than that.

There may be a freq of pulsing the led that the plants like and possibly a freq that they dont like.

Most plants, especially when young, their leaves and branches very noticeably reach for the sun and settle down at night.  If they lean away from a freq they dont like, then maybe dont use that freq. The leaning toward or even leaning away from a freq of light would be cool to see if it happens, and would be a quicker indicator of proper, or not, freq rather than waiting for just growth health and speed.

It would have to be tested. But I wouldnt negate the possibility that pulsing them may be beneficial or even no problem at some freq.



Mags






MarkE

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Re: High Efficiency LED for Joule Thief, etc.
« Reply #32 on: August 21, 2015, 05:42:46 AM »
"I do understand that PWM would NOT be acceptable for growing crops ,you can trick the eye But not mother nature [thx Brad]."

Well that would need to be tested. Remember sliders little circuit that emitted high freq and plants near by grew better. What was it, 27mhz?  Leds should be able to produce that, as I think optical fiber data transmission I believe is much higher than that.

There may be a freq of pulsing the led that the plants like and possibly a freq that they dont like.

Most plants, especially when young, their leaves and branches very noticeably reach for the sun and settle down at night.  If they lean away from a freq they dont like, then maybe dont use that freq. The leaning toward or even leaning away from a freq of light would be cool to see if it happens, and would be a quicker indicator of proper, or not, freq rather than waiting for just growth health and speed.

It would have to be tested. But I wouldnt negate the possibility that pulsing them may be beneficial or even no problem at some freq.



Mags
Raw PWM is primarily a way to save money on parts.  If pulsing were a problem, the same average light output can be had by PWM'ing into an LC low pass filter so that the current ripple, and therefore light variation is very small.  PWM rates above around 100kHz will start to distort due to the turn-off time of the LEDs.  If RF does something good for the plants, it is probably more practical to just set up a separate transmitter.

ramset

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Re: High Efficiency LED for Joule Thief, etc.
« Reply #33 on: August 21, 2015, 06:50:29 AM »
Mags
Yes the 27 MHz would of course be tested here too(the company from Ireland's tech)
Your idea to watch the little fellows and their reaction is very cool and makes me want to do the best possible job !!
Tinsel
What is an appropriate amount of lights for you to test (watt load) ?

Mark E
Your input is greatly appreciated !

Respectfully
Chet

Magluvin

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Re: High Efficiency LED for Joule Thief, etc.
« Reply #34 on: August 21, 2015, 07:14:27 AM »
Raw PWM is primarily a way to save money on parts.  If pulsing were a problem, the same average light output can be had by PWM'ing into an LC low pass filter so that the current ripple, and therefore light variation is very small.  PWM rates above around 100kHz will start to distort due to the turn-off time of the LEDs.  If RF does something good for the plants, it is probably more practical to just set up a separate transmitter.

Back in 8th grade, I bought al laser diode and I think it was 7 9v batteries and built a circuit from a book at the library.  I think it was only 10khz operation. But the book explained that the pulsing circuit enabled the lasing function. Dont remember the wording on that for sure.  was back in 78.  But later I played with the idea of getting an led, 10m red radioshack, to produce the lasing function.  It was like a region of pulsed current operation that gave some turbo to the output.

Those 10mm reds produced a half decent image of the square chip on a wall.  Use a magnifying glass and it becomes so visible in detail, you can see on the wall/white paper the anode wire and a darker spot where it connects to the chip.

When I pulsed it trying diff freq and input levels, when you get close, you will see just one side of the chip emit a much brighter light. Increase input very gradually and another side brightens, and so on till all sides are kickin. 

Dont remember if it was necessary back then to get the lasers to work properly, and now they can just be dc in, but the effect on the led can be had regardless. The JTs are possibly pushing the leds in this lasing region.   The laser diode I used was IR and I used a dental exray test card from my uncle to see the beam. But when the batteries got low, the beam would sorta fall out and perform more like an IR led and no coherent beam.  Lol. Actually tried to file the side of an led, cutting away some of the alum bowl that holds the chip, to hopefully get a beam out the side. Very wishful and ambitious thinking. Was very careful with what tools I had. But always seemed to kill or short/damage the chip before I could end up seeing light from the chips edge.

IR lasers were $27 back then. Red were out of my price range. Way out if I remember correctly.

Mags


MarkE

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Re: High Efficiency LED for Joule Thief, etc.
« Reply #35 on: August 21, 2015, 12:38:30 PM »
Back in 8th grade, I bought al laser diode and I think it was 7 9v batteries and built a circuit from a book at the library.  I think it was only 10khz operation. But the book explained that the pulsing circuit enabled the lasing function. Dont remember the wording on that for sure.  was back in 78.  But later I played with the idea of getting an led, 10m red radioshack, to produce the lasing function.  It was like a region of pulsed current operation that gave some turbo to the output.

Those 10mm reds produced a half decent image of the square chip on a wall.  Use a magnifying glass and it becomes so visible in detail, you can see on the wall/white paper the anode wire and a darker spot where it connects to the chip.

When I pulsed it trying diff freq and input levels, when you get close, you will see just one side of the chip emit a much brighter light. Increase input very gradually and another side brightens, and so on till all sides are kickin. 

Dont remember if it was necessary back then to get the lasers to work properly, and now they can just be dc in, but the effect on the led can be had regardless. The JTs are possibly pushing the leds in this lasing region.   The laser diode I used was IR and I used a dental exray test card from my uncle to see the beam. But when the batteries got low, the beam would sorta fall out and perform more like an IR led and no coherent beam.  Lol. Actually tried to file the side of an led, cutting away some of the alum bowl that holds the chip, to hopefully get a beam out the side. Very wishful and ambitious thinking. Was very careful with what tools I had. But always seemed to kill or short/damage the chip before I could end up seeing light from the chips edge.

IR lasers were $27 back then. Red were out of my price range. Way out if I remember correctly.

Mags
Ordinary LEDs do not operate as LASERs.  JTs are essentially boost mode DC-DC converters.  When the voltage is greater than LED Vfw the LEDs light.  Current to an ordinary LED can be managed with a simple current limiting resistor.  That is entirely impractical with a LASER diode.

Cherryman

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Re: High Efficiency LED for Joule Thief, etc.
« Reply #36 on: August 22, 2015, 09:13:20 AM »
"I do understand that PWM would NOT be acceptable for growing crops ,you can trick the eye But not mother nature [thx Brad]."

Well that would need to be tested. Remember sliders little circuit that emitted high freq and plants near by grew better. What was it, 27mhz?  Leds should be able to produce that, as I think optical fiber data transmission I believe is much higher than that.

There may be a freq of pulsing the led that the plants like and possibly a freq that they dont like.

Most plants, especially when young, their leaves and branches very noticeably reach for the sun and settle down at night.  If they lean away from a freq they dont like, then maybe dont use that freq. The leaning toward or even leaning away from a freq of light would be cool to see if it happens, and would be a quicker indicator of proper, or not, freq rather than waiting for just growth health and speed.

It would have to be tested. But I wouldnt negate the possibility that pulsing them may be beneficial or even no problem at some freq.



Mags


Some people use moving lights or plants to cover more m2 with less light.


So..   a moving light could also be seen as a frequency.
Wind moving leafs in and out of shadow.. is also a frequency.


Although the more light the better i presume..  one might be able to get a descent result with way less energy use by pulsing.


 

MarkE

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Re: High Efficiency LED for Joule Thief, etc.
« Reply #37 on: August 22, 2015, 01:11:46 PM »

Some people use moving lights or plants to cover more m2 with less light.


So..   a moving light could also be seen as a frequency.
Wind moving leafs in and out of shadow.. is also a frequency.


Although the more light the better i presume..  one might be able to get a descent result with way less energy use by pulsing.
There should be some maximum intensity of light beyond which there is no benefit and potentially even harm.  As to pulsing I doubt tha it does any good on its own.  We know from experience in northern latitudes that huge plants can be grown when exposed to light nearly 24/7.  So 24/7 continuous light is probably your baseline, and the object would be to find optimum intensity.  Once one has such a baseline, then one can do things like pulse width modulate to try and see if higher yields per average lighting Watt can be had.

SoManyWires

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Re: High Efficiency LED for Joule Thief, etc.
« Reply #38 on: August 22, 2015, 04:41:20 PM »
There should be some maximum intensity of light beyond which there is no benefit and potentially even harm.  As to pulsing I doubt tha it does any good on its own.  We know from experience in northern latitudes that huge plants can be grown when exposed to light nearly 24/7.  So 24/7 continuous light is probably your baseline, and the object would be to find optimum intensity.  Once one has such a baseline, then one can do things like pulse width modulate to try and see if higher yields per average lighting Watt can be had.

yes the lights would need to be brighter to be able get more in harvest yield when using the same area of space, not accounting for other variables, such as temperature, humidity, c02 levels (though plants can more effectively digest c02 in slightly warmer temperatures), the plants ability to use whatever its given for plant food, and placement in respect to the light source.

there is ways to place the plants to be able to take greater advantage of the light source(s).
one example is the Omega garden system that uses no light reflectors, as it can rotate the plants themselves around the light, rather than using a linear light moving rail system. though cleaning the omega system might be an issue.
this makes good use of light when not wanting to pay as much on the power bill.
the light in that system is sealed to protect from water damage, and is placed in the centre of a vertically rotating structure that holds the plants in place, allowing the plants to move around the light.

there are lots of other different garden designs than that one too that make good effective use of a individual light source.

the concern with a individual light source being expected to become usable light is plants can get burnt from heat radiation
if kept too close to the light, airflow has been used to redirect the heat away from the source by using exhaust venting,
and even venting sometimes is not enough as the plants continue to grow towards light, leading to a schedule for adjusting light distance that becomes more important according to the heat.



am thinking that to get higher yields using PWM more effectively with the same input power, a crop would need to be using twice the square footage in garden space (ground coverage) than to try to expect any kind of greater yield from half the space if using the same input wattage, and would need more sources of light to match the area.








Magluvin

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Re: High Efficiency LED for Joule Thief, etc.
« Reply #39 on: September 08, 2015, 03:20:04 AM »
I had talked to Chet a while back about indoor gardening, of food, of course. ;D

Here much later on I am going to try a few things.

What I have envisioned is grow modules. Modules that can stack against a wall in an apartment say where you dont have much option for growing food..

The construction material of choice for me is 1/4in pvc board. Light weight, water proof and easy to work with.

Below I have some pics of leds Im going to try.  A 5m real of blue and 5m roll of red.  Also have a role of UV to try with the blue n red. Led spacing is about 5/8in.  Average of about $12 a roll on amazon. Banggood.com even less.

Running the blue and red rolls together use 5.9A at 13.1v. 77w

The strips can be cut at intersections and solder wire to make new connections to consecutive strips. Not sure what size cabinet to make yet, or if it will need all 10 yards of blue n red, along with uv strips.

Its not always that the light has to come from only above the plants. Side lighting helps keep plants short, not having to reach for the light and keeping stem lengths short. More bushy and more nodes for fruit like strawberries, and denser thicker greens.

And if all works out well, the cabinets can be small, stackable, where one could have a full garden on one wall of an apt or room in a house, without taking up much living space.

Will make a new thread if there is some interest shown to do so.


I have some hope for these led strips. It allows easy mounting, self stick, and the ability to easily line the ceiling and walls of the cabinet. And I think its cheaper than what they have out there for the purpose.

Also looking into mylar for added reflection of light. Any light that does not 'end' up on the plant is wasted. Mylar is over 99% reflective. Shiny side of al foil is about 77%. Actually a titanium white paint is better than foil.

Mags

SoManyWires

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Re: High Efficiency LED for Joule Thief, etc.
« Reply #40 on: September 08, 2015, 07:26:02 AM »
I had talked to Chet a while back about indoor gardening, of food, of course. ;D

Here much later on I am going to try a few things.

What I have envisioned is grow modules. Modules that can stack against a wall in an apartment say where you dont have much option for growing food..

The construction material of choice for me is 1/4in pvc board. Light weight, water proof and easy to work with.

Below I have some pics of leds Im going to try.  A 5m real of blue and 5m roll of red.  Also have a role of UV to try with the blue n red. Led spacing is about 5/8in.  Average of about $12 a roll on amazon. Banggood.com even less.

Running the blue and red rolls together use 5.9A at 13.1v. 77w

The strips can be cut at intersections and solder wire to make new connections to consecutive strips. Not sure what size cabinet to make yet, or if it will need all 10 yards of blue n red, along with uv strips.

Its not always that the light has to come from only above the plants. Side lighting helps keep plants short, not having to reach for the light and keeping stem lengths short. More bushy and more nodes for fruit like strawberries, and denser thicker greens.

And if all works out well, the cabinets can be small, stackable, where one could have a full garden on one wall of an apt or room in a house, without taking up much living space.

Will make a new thread if there is some interest shown to do so.


I have some hope for these led strips. It allows easy mounting, self stick, and the ability to easily line the ceiling and walls of the cabinet. And I think its cheaper than what they have out there for the purpose.

Also looking into mylar for added reflection of light. Any light that does not 'end' up on the plant is wasted. Mylar is over 99% reflective. Shiny side of al foil is about 77%. Actually a titanium white paint is better than foil.

Mags

good idea you have there!
and yes it does make sense trying to utilize more than only one light source, and can help create a more stable even temperature.
(less node stretching your right)

is there enough usable light the plants will respond to with just the LED strip rolls that are being used?
plants do enjoy their radiation.
the more radiation they have without going overboard, the better. similar to a engine fuel for performance.
in eco mode, less fuel.

the result of not enough 'useable light' is smaller tomatoes, and more green leafy produced plant matter,
though you are probably wanting less leafy matter, and instead more tomatoes.

most plants would prefer to be under conditions that would cause people to get sunburns, and mutations.

airflow should be allowed. this can also help control the heat that results from applying enough radiation,
and also convert the plants starch towards creating strength to withstand the weight of tomatoes.

also be aware of Ph levels being not low enough such as tap water.
too low though, can make for shock, ideally somewhere around 6.0 - 6.3.
and for plants just germinating, the ph can be allowed to be a little lower to about 5.5 - 5.8.

more importantly than adjusting ph levels for already developed plants (with roots, ones without roots have very little plant food requirement and will do just fine getting by on what clorophyl they already have until later) is not expecting the plant
to live on a water diet, it also wants some kind of a plant food.

imagine you already are aware of much of that, though its helpful to knowledge that should others consider such an idea that could save time and R&D expense.

also, if saving power is important, then only 18 hours of artificial light (or any light) is all thats needed until at which point the plant is allowed to experience shorter photovoltaic periods at about 12 hour cycles instead until harvest with the help of a timer.

so, more tomatoes, or more lettuce, that is choice.

another thing to be concerned about, is how effective is the adhesive mentioned thats being relied on to withstand the climate they are being used in.

mylar is best, though ya just using white paint can be effective if not easier to clean (if semigloss or higher).

growing in a small containment will mean the temps will rise, this is when a small amount of c02 introduced into the system can be most effective if careful enough to not just exhaust the c02 away from the small containment zone before it can be of use. just try not to place the exhausted c02 into another contained environment that people could be affected by.

all the best