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Actually, regarding the costs, I've made calculation (including cost of lamp but also cost of current) and it's cheaper in the long term for me with the LED.

The LED are more efficient than normal lamp in term of light / amount of current. So more ecological, which is important for me.

What is the efficiency value of your LED lamps?

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Hello everyone, sorry for my english :) I open this topic to share my experiments with LEDs. I made a long study of white LEDs, I discovered that their light is better than the common fluorescent la

blue and red are a hoax to spend lots of money to people, plants need to grow well many more colors, blue and red are the basic colors only for chlorophyll type A. The sun radiates light is color whi

I have been reading this thread with some interest as I have used LED's for a few years now. The Technology is moving quite rapidly and is difficult to keep up but is certainly improving. I currentl

That would be my question as well.

Modern CMH lights give you 100lm per Watt (or more), last 20.000 hours, and after 10.000 hours still have more than 80% of their max. luminous flux. Have a colour rendering index over 90, and lights cost less than 1€ per Watt.

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Hi,

Sorry, but I don't have precise figures on the efficiency, since I don't have the apparatus to measure.

What I compared was data I could collect at the time I bought my lamp and it was a rough calculation comparing one LED lamp like mine versus fluorescent tubes. Hmmm, maybe I shouldn't have spoken about efficiency without precise numbers... :whistle3:

I have to say I did not take CMH lights into account.

One of the main advantage for me was that the emission spectra of the LED was not changing upon time.

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For plant light (deep red and royal blue) the efficiency is not so easy to compare. For white light it's lm/w but for royal blue lumens aren't even specified but a radiant flux of mW. For deep red lumens are defined but lm/w is low because lumen is defined through white light.

vincent, I used these leds in my plant light:

http://www.ebay.co.uk/itm/161069178473

http://www.ebay.co.uk/itm/221247436119

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Thank you pmatil!

If other people have info + feedback on specific LEDs, in particular red and blue ones, feel free. ;-)

For white, it seems that XM-L2 are the best, but I'm still wondering which ones are the most efficient ones for red and blue.

My plan is to have something like 50% of white (mix of warm white and cool white) and 50% blue + red.

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http://www.ebay.co.u...=item4d138e5d48

Three of these each driving strings of 3 Watt LEDs would be an easy way of doing things. The constant current needed for the LEDs is adjusted with a potentiometer. An old laptop power supply (which are usually 19 volts) could allow strings of four LEDs. Three strings each of four LEDs would allow the use of varying devices eg royal blue, blue and white.

I have edited my post because 5 Watt LEDs are made up internally of LED chips in both parallel and series and therefore they run on about 10 volts - you therefore cannot run more than one from a laptop power supply.

Edited by Peabody
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Hello,

@ vincent,

I recommend using osram oslon SSL diodes. You can get them in nearly all colors needed for a good grow light.

I also use these LEDs.

Some pictures can be seen here:

http://forum.carnivoren.org/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=52149

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Hello,

yes i´m using the PT4115 buck converter. The shunt resistance is at about 0.15 ohms. That gives me an output current of 0.7 amps.

I got my LEDs from a german supplier called Reichelt.

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LEDs work ok, from seed to adult plant, but natural daylight works better and at the end of the day you can heat an outside terrarium, (well insulated) for what it costs in power for an LED. Personally i dont see much advantage in optmising wavelengths, it's slightly cheaper than an envirolite, but not by much, and costs more to buy). If at all possible use daylight and insulate well.

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Thanks for those who provided some tips for me to build my own set-up. I'm now selecting the LEDs.

I also want to say that I fully agree with the last sentence of manders post: try to maximise the use of natural light! Personally, I always put my terraria next to a window. The artificial light is only an addition, to compensate cloudy days or short days in winter.

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It all depends on which group of plants you'd like to grow. For some time during this year's summer I've put my smaller Heliamphora terrarium on NE facing windowsill to make sure that plants are getting more natural light. Temperatures were easily getting up to 40 degree Celsius which is considered to be lethal to Helis. So unless you have some powerful cooling system I wouldn't recommend putting highland things on the windowsill.

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Many people do not have the technical knowledge, equipment, or time to be able to construct their own lamps. Even for someone like myself, who is perfectly capable of designing and constructing such, it is a lot of hassle. Nowadays I tend to purchase pre-build lamps, even when I know that I could probably construct something a little more optimises.

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I was looking for some red LEDs, and I found this:

http://www.aliexpress.com/item/Free-Shipping-1pcs-10W-High-Power-LED-Far-Red-660nm-For-Plant-Grow-Light/1084474823.html

Could be interesting!

Anyone tried it?

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I was looking for some red LEDs, and I found this:

http://www.aliexpress.com/item/Free-Shipping-1pcs-10W-High-Power-LED-Far-Red-660nm-For-Plant-Grow-Light/1084474823.html

Could be interesting!

Anyone tried it?

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Vincent.

It seems that Blue light is needed for leaf growth and Red light for flowering.

The 3 Watt LEDs would allow an array to be be made that would cover a bigger area than a single 10 Watt LED.

Many of the devices from

http://stores.ebay.co.uk/acrchobby

are not surface mount and can be easily hand soldered to the star shaped plate which they supply with each LED.

Possibly a greater number of 1 Watt LEDs would allow a more even distribution of light from different wavelengths of LED.

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They all are surface mount. In fact, most of the leds also have a solder pad on the bottom of the led which is really impossible to solder without paste and reflow oven. But then in chinese (cheap) led lamps the bottom pad is not soldered but heat conducting paste is used. It's not as good as soldering the pad. And the pad is mainly for conducting the heat away.

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Soldering sourface mount LEDs isn' t very difficult. It is even possible to do this with a slightly modified standard soldering Iron.

I soldered many LEDs without a reflow ofen and solder paste just with a soldering Iron, and the LEDs are still working perfektly. ( since 3 years now)

It anyone is interested in how this method works i will make a short documentation.

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Hello,

at fist i tinned the aluminum-core PCB (star pcb). To do this i screwed a 4mm thick copper plate to a large and flat soldering iron tip.

I startet to heating the star-PCB until the tin has melted. Then pushed the pcb on a heatsink. (The black surface next to the copper surface)

After the pcb was cold i sanded down the tinned soldering pads a bit, so that the LED coul be put flat on the soldering pad.

So i placed all three LEDs on the PCB and started heating it again with the soldering iron. After the tin has melted and the LED was soldered on, i pushed the PCB on the heatsink.

pictures can be seen here (pic 3,4 and 5)

http://forum.carnivoren.org/index.php?/topic/34093-led-informationen-und-dokumentation-fuer-eine-zusatzbeleuchtung/

Edited by Karl H.
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Hi everyone,

I am wondering about the definition of the emission angle of the LED lenses.

Basically, if I take a LED with 125° emission and I put a 30° lens, what will be the final spatial distribution? Option A, B or C (or another)?

I know that option A is the common definition of the emission angle of the LED itself, but what about LED + lens?

If anyone know...

lenses10.jpg

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Hallo,

i just want to show you my new LED grow light.

The whole thing is about 10x4x4 cm big. So ist actually very small considering that it consumes about 30W.

DSC 0678 (FILEminimizer)

DSC 0680 (FILEminimizer)

DSC 0681 (FILEminimizer)

DSC 0686 (FILEminimizer)

Hope you like it :)

greetings

Karl

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