Abiqua
Well-Known Member
it will still push 500 ppfd...i generally averaged a g/w and one or two phenos that would double that ........
Bridgelux EB Series Build
- Thread starter brahbbyB
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Abiqua
Well-Known Member
@robinncnn and @caretak3r both have threads using these....and no i am not tagging robin because of the quantums....before that he was working those type of strips.....
excellent quality imho cant go wrong
mauricem00
Well-Known Member
7 strips in series uses 154 volts. a bridge rectifier and capacitor converts 120 vac to 160 vdc. a simple constant current sink is cheap and powers the array http://www.radiolocman.com/shem/schematics.html?di=113034 I use the circuit from figure 2 1.2 ohm 2watt for R1 500k ohm 1/2 watt replaces R2 and 3. with the parts I use current came out to 540 ma. and the arrays gives me 13500 lumens. a 150 watt CMH bulb produces 13000 lumens so this would give me an accurate comparison. the constant current sink only needs a minimum of 1 volt to function properly and the IRF 640 tmos fet is rated for 200 volts. I have had formal training in electrical engineering and medical and industrial electronics and I know horticulturalist that run local nurseries that I talk to for advice on growing plants indoors. they actually think I'm crazy trying LEDs and my main grow uses T5s but I like to experiment
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BuddyColas
Well-Known Member
I’m glad I asked. I have worked over 40 years as an electronic technician, so I understand the circuit you are talking about. Thus far I have stuck with Meanwell drivers and have not tried to home-brew a driver…yet.
Like Abiqua I had your PPFD at about 540. I bit low for me, but if you’re getting it done with 13000 lumens…you should do much better with the strips. You can move your strips down within a few inches and not toast the girls. And the strips make for a much more even PAR map than the CMH.
I’d like to see how you do. Are you going to start a grow thread or post occasionally on this thread?
Crazaer
Active Member
Ok. I have a small file cabinet. 15" x 18" x 29". If I squeeze 10 of the EB 4k 10" strips in there, run on a HLG-185H-C700A but dimmed down a bit, will I be totally oversaturated for veg growth? And, if so, how many strips should I run in that space? Apologies for my inadequacy with driver and ppfd math. Ideally, I'd like the ability to raise both bonsai moms and babies in the same cabinet.
caretak3r
Well-Known Member
I'd love to see a pic if you are able to post. How efficient do you think this simple circuit is?
nogod_
Well-Known Member
In a word: absolutely.
The 280mm strips are 7.7w @ 350ma. Which means at 350ma you would be vegging at ~40w sqft. You need maybe half of that and thats pushing it.
Meanwell makes tons of different drivers. For your space you would be perfectly happy with 5-6 strips on an hlg-60h-c350a
I have never understood keeping moms and kids in the same cabinet beyond same light schedule. You want explosive growth out of your kids but the old lady...not so much.
The 280mm strips are 7.7w @ 350ma. Which means at 350ma you would be vegging at ~40w sqft. You need maybe half of that and thats pushing it.
Meanwell makes tons of different drivers. For your space you would be perfectly happy with 5-6 strips on an hlg-60h-c350a
I have never understood keeping moms and kids in the same cabinet beyond same light schedule. You want explosive growth out of your kids but the old lady...not so much.
BuddyColas
Well-Known Member
I too would like see your build. And know the value of the cap you found effective.
Crazaer
Active Member
I figured, but thought it would be best to ask.
Isn't PPFD more relevant than watts?
Thank you for the driver recommendation, I am looking at the spec sheet now. Can anyone tell me what the PPFD would be for 6 of the 280mm strips, with that driver?
It's the space I have, plus money/time available, plus interest in a new project. With unlimited funds, time, and space I would do it differently.
mauricem00
Well-Known Member
the power company has a transformer across the street from my house so my line voltage is very stable and efficiency with this simple drive runs at 96% or better. at the drive current im using im getting about 163 LPW from the strips. with simple air cooling and no heatsinks they are inexpensive and light weight. one thing i've learned is that with LEDs plants do not absorb nutrients as well as with other lights so they need more aggressive feeding to prevent deficiencies and supplemental UV and VIOLET light during flowering helps with potency and taste.a power veg bulb works well for this. these pictures were taken during construction and only 4 strips out of 7 were lit in the second picture but it does show how uniform the light is distributed. you can also see that they are mounted on a simple open wood frame to allow for good airflow. on the power supply im using (2) 470uf 200volt capacitors salvaged from an old computer power supply.
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PicklesRus
Well-Known Member
Are you saying that white LED lights require supplemental UV/Violet lighting for proper nutrient uptake?
If that's the case you can get LED UV/Violet light. So it's not the LED light that's the problem it's the spectrum of the white LED?
mauricem00
Well-Known Member
uv and violet LEDs are very inefficient. CLW uses a UV finishing tube in their LED grow lights and what I said is that it stimulates THC,CBD and TERPENE production and this is an established fact. tubes are the most effiecient way to provide this spectrum.why is it that anytime anyone says LEDs are not magic miracle lights someone acts as if you have insulted their god?no grow light is perfect. we all use what works best for us. cal mag deficiency are a well known problem with LED grow lights
caretak3r
Well-Known Member
I'm really interested in learning more, however, I do not have an electronics background so I need to study up on the schematic posted. there's been talk of doing this before, but I've never seen anyone actually do it. Maybe we can break out a discussion for DIY drivers. I don't take electricity lightly, but I'm definitely interested in learning more.
mauricem00
Well-Known Member
I am always concerned when someone with no training in electronics starts playing with high voltage. learn how to handle high voltage before you start playing with this stuff' one trick an old TV repair man told me years ago is to keep one hand in your pocket when working on a live circuit but please do not try this kind of DIY until you are more comfortable wiring circuits and working with high voltage. you could start a fire or even kill yourself and we already have plenty of candidates for the DARWIN AWARD
. another person here made a COB array using reactive transformerless drivers so some people on this site know electronics. perhaps you can find an electronics student from the local college to help you with this.
Abiqua
Well-Known Member
you need to find the definite LER (probably 324/325) and the approximate umol/s per joule...some of that info is in the cob effiency sheets thread...i google those three words with riu and its the 1st result usually...
calculating ppf /ppfd
1.
you need the LER to calculate efficiency
example: at 350 ma this gives 159 lumens/ watt 4K......that would be 49% (324 LER)and 48% (325 LER)
.....159/324 = .49xx etc
2.
calculate ppf
ppf is calculated by taking the amount of light emitted by your effiency and total watts (PAR watts)
.and then multiplying the umol/s per joule x PAR watts
example: 6 bars @350ma is 7.7 watts x 6= 46.4 watts total x .49% eff = 22.736 PAR watts
if the umol/s per joule is 4.70....then PPF = 22.736 x 4.70 = 106.85 PPF
3. Calculating PPFD
...ppfd is just a function of ppf in a square meter....meter squared is 39.37" *39.37" = 1549.99 inches
ppfd = ppf in a square meter (1)
example:
ppfd in 12 inch by 12 space using your PAR
144inches 144\1550 = .09 meter squared
106.85 \ .09 = 1187 ppfd
Abiqua
Well-Known Member
i think you could use half or 6 strips and be more than good....
Crazaer
Active Member
Thank you for breaking it down for me. I went to the calculator program page and it was intimidating but the way you explained it is much more manageable!
From what I've heard, I should be aiming for 400-500 PPFD so I think you're right that 3 strips (even under driven more) would be closer to the ideal ballpark range.
Thank you, again!
nogod_
Well-Known Member
The ppfd example Abiqua gave is for a 12"x12" square, in your space (using those numbers) you would top out at 612ppfd using 6 strips.
Dim that down to start (version A dims to 50% internally) and ramp up as needed.
Dim that down to start (version A dims to 50% internally) and ramp up as needed.
PicklesRus
Well-Known Member
Hey man I don't know if the statement you made above is referring to my questions but if so you got me all wrong. I'm just asking a question. Other people might get defensive about their lights but I could give AF less I'm just trying to learn.
According to the spectrum map of my White LEDs and a gavita HPS, they both give off violet and UV. The Gavita shows maybe a little more UV but it's like a hairline on the map. Are you saying that HPS works better than white LED for flowering, because of the UV? Or are HPS also not that good at providing UV?
Bridgelux White LED strips
HPS
I found this:
There are three spectrums of UV light. UVA is the least harmful. This is the spectrum produced by black lights. UVC light is dangerous to all life. It is used in water purification systems to sterilize water.
The light spectrum of interest to us is UVB. It affects life in many ways. In humans it causes tanning, skin aging, eye damage and cancers. Other animals are affected by it in all sorts of ways.
The Earth’s atmosphere filters UVB light. There is more UVB light at high altitudes than at sea level. Also, sunlight at the equator takes the shortest route through the atmosphere. As the latitude increases, sunlight reaches Earth after going through more atmosphere because of its slanted path. Therefore UVB at the equator is much more intense than in temperate zones. That’s one reason people tan or burn so fast in the tropics, and why skin cancer rates are higher in southern than northern states.
A researcher conducted a controlled experiment in a greenhouse. He lit a group of high potency plants similarly except with the addition of UVB light to some groups. He found that the percentage of THC increased in a direct ratio with the increase in UVB light. This research confirms the adage that high altitude plants are more potent than those grown at low altitudes.
If you look at old-world land races of cannabis, plants that have become adapted to the climate and latitude, the ratio of THC to CBD starts at 100 : 1 at the equator. At the 30th parallel (The Hindu-Kush Valley) the plants have a ratio of 50 : 50. At the 45th parallel the ratio is near 1 : 100. This corresponds roughly with the amount of UVB light received at these latitudes. There is much more UVB at the equator than the 45th parallel.
How can you get more UVB light to your plants? Certainly it’s true that MH lamps emit more UVB light than HPS lamps. Still the amount that MH lamps emit is small. In fact, many manufacturers use UVB shielding glass to filter out most of the UVB that’s produced. The UVB light the plant receives from an MH lamp does increase the plant’s potency slightly at the cost of yield, but there are better ways to introduce UVB light into the grow room. They include reptile lights, which emit about 10% UVB, and tanning lamps.
The problem with using these lamps is that they are associated with increased number of cancers and many other problems. They should not be on when you are in the grow room.
After reading that, it sounds like conventional grow lights like MH, HPS, LED, T5, Induction - none of them give off significant amounts of UVB.. soo..... back to my original thought:
You said LEDs require more nutrients or supplemental UVB, .. compared to what? HPS?
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