High Efficiency LED for Joule Thief, etc.

[MarkE]

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]

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]

"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]

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]

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