90W homemade LED grow

[Slipon]

maybe use a separate driver for the 660, that way you can also turn em on after the stretch (first 2-3 weeks of flowering) and save some power in the early growth where it is`t need as much as in full flowering

2600-3700K sounds good but 67 lm less is like 20% less

IMO optic is`t that important, if you only intent to grow short auto`s or use a scrog method or similar, I have one panel with and one with out, the one with out do great, just keep it at 10-20cm instead of the 40cm I keep them with optic on, at 25cm I actually get light belch with the optic at 10cm with out I don't, just that lower Bud`s get less light, but they do anyway as you have to keep it at 40cm, atleast get some that spread the light out a lot like 120 degree angle, if it was me I would use the money "saved" on the optic to just trow in more LEDs, and I would also make sure to spread em out over my hole grow, either by making a hugh panel or a few smaller once, a small "ufo" could work great for each plant, looking back I would rater have that then one big panel as it don't spread the light like big HIDs

just my experience

 

[JMD]

maybe use a separate driver for the 660, that way you can also turn em on after the stretch (first 2-3 weeks of flowering) and save some power in the early growth where it is`t need as much as in full flowering

2600-3700K sounds good but 67 lm less is like 20% less

IMO optic is`t that important, if you only intent to grow short auto`s or use a scrog method or similar, I have one panel with and one with out, the one with out do great, just keep it at 10-20cm instead of the 40cm I keep them with optic on, at 25cm I actually get light belch with the optic at 10cm with out I don't, just that lower Bud`s get less light, but they do anyway as you have to keep it at 40cm, atleast get some that spread the light out a lot like 120 degree angle, if it was me I would use the money "saved" on the optic to just trow in more LEDs, and I would also make sure to spread em out over my hole grow, either by making a hugh panel or a few smaller once, a small "ufo" could work great for each plant, looking back I would rater have that then one big panel as it don't spread the light like big HIDs

just my experience

Gonna skip the optics then I guess Gonna go for better LEDs instead.

I think the spread will be sufficient with the arrangement I've shown in a few posts back, wouldn't you say?

Gonna see what price the seller can offer the good LEDs at.

 

[Slipon]

Gonna skip the optics then I guess Gonna go for better LEDs instead.

I think the spread will be sufficient with the arrangement I've shown in a few posts back, wouldn't you say?

Gonna see what price the seller can offer the good LEDs at.

yea more better quality LEDs is to prefer over optics IMHO, we don't want to grow tree`s indoors anyway, measured with my cheap light meter (Lumens) I see good light at 0-40cm with out optic, and with maybe at 30-80cm just make sure you keep your top/Bud`s at 10-40cm

and make sure to use the hole panel, Etc. make a row at the edges and less in the middle if that make any sense to you, if I should put 800W in to a panel I would like to be able to grow atleast 4 medium size plants under it or maybe 8-12 small Auto`s and that would need like 4x4 ft (120x120cm)

so wouldn't like to put them 800W in to a panel less then 1x1m then, guess I might make two on 400W each, that would also make it possible to "only" run 400W wile the plants are small and don't fill out all the ground, would feel kind a stupid to run 800W over 8 seedling`s

 

[JMD]

yea more better quality LEDs is to prefer over optics IMHO, we don't want to grow tree`s indoors anyway, measured with my cheap light meter (Lumens) I see good light at 0-40cm with out optic, and with maybe at 30-80cm just make sure you keep your top/Bud`s at 10-40cm

and make sure to use the hole panel, Etc. make a row at the edges and less in the middle if that make any sense to you, if I should put 800W in to a panel I would like to be able to grow atleast 4 medium size plants under it or maybe 8-12 small Auto`s and that would need like 4x4 ft (120x120cm)

so wouldn't like to put them 800W in to a panel less then 1x1m then, guess I might make two on 400W each, that would also make it possible to "only" run 400W wile the plants are small and don't fill out all the ground, would feel kind a stupid to run 800W over 8 seedling`s

But that's the smart thing.. I will make it possible to run 4 modules on just one driver. This will increase the efficiency of the LEDs.

 

[Slipon]

But that's the smart thing.. I will make it possible to run 4 modules on just one driver. This will increase the efficiency of the LEDs.

ahh ok, so like dimmerble I guess, smart

 

[JMD]

ahh ok, so like dimmerble I guess, smart

Yea sort of. Being able to turn on or off drivers when 4 modules are connected in parallel, will yield 375mA, 750mA, 1125mA or 1500mA.
When running with 4 drivers (one for each module) they will no longer run in parallel, but as independent circuits.

 

[anomuumi]

Yea sort of. Being able to turn on or off drivers when 4 modules are connected in parallel, will yield 375mA, 750mA, 1125mA or 1500mA.
When running with 4 drivers (one for each module) they will no longer run in parallel, but as independent circuits.

Nice genuine solution. Does that kind of circuit need some kind of protection, in case of a string failure? How do you keep the string currents equal? I think there was some kind of a problem with parallel circuits in a commercial panel, some leds being dim and others overdriven by unequal drive currents.

 

[JMD]

Nice genuine solution. Does that kind of circuit need some kind of protection, in case of a string failure? How do you keep the string currents equal? I think there was some kind of a problem with parallel circuits in a commercial panel, some leds being dim and others overdriven by unequal drive currents.

I will protect each string with a slow burn fuse. If I drive 4 modules with 3 drivers, and a module fails, then the remaining 3 modules will be driven at their max rated current.

If you just connect the modules in parallel, they won't get the exact same current. But this is mainly a problem if you are using a CV (constant voltage) source or if you drive you LEDs close (or at) their maximum rated current.
The problem with LEDs are that they are non-linear, with a negative temperature voltage coefficient. When the temperature increases, the voltage drop across the LED drops a few mV - which results in an increased current with a CV source.

By adding a resistor to each string, you can counter-act the behavior of the LEDs. But when you are driving them well below their maximum rating, you should be able to avoid the problems.

 

[Flame21]

How well would a setup using:

2x 100W 2700K leds: http://www.topledlight.com/100w-warm-white-high-power-led_p275.html
and
2x 100W 3200K cree leds: http://www.topledlight.com/100w-cree-xmlu2-led-multichip-100-watts-warm-white-light-9000lm-copper-plate_p1328.html

All running at 3amps for a total of about 400W work out. It should come out to something like 26000 lumens. Would I need to buy separate blues and reds still, or will these two warm white color ranges be sufficient. Should I just stick with the higher lumins cree 3200K leds, or stick with just the 2700K leds for better colors?

EDIT:
I don't mean to sidetrack your thread, but you've really inspired me, and you seem to know a good deal about creating LED arrays.

 

[Slipon]

could work Im sure, tho if it was me I would look for 5000K instead of 3200K maybe just one then, in the middle of the 3x2700K

 

[Chronikool]

How well would a setup using:

2x 100W 2700K leds: http://www.topledlight.com/100w-warm-white-high-power-led_p275.html
and
2x 100W 3200K cree leds: http://www.topledlight.com/100w-cree-xmlu2-led-multichip-100-watts-warm-white-light-9000lm-copper-plate_p1328.html

All running at 3amps for a total of about 400W work out. It should come out to something like 26000 lumens. Would I need to buy separate blues and reds still, or will these two warm white color ranges be sufficient. Should I just stick with the higher lumins cree 3200K leds, or stick with just the 2700K leds for better colors?

EDIT:
I don't mean to sidetrack your thread, but you've really inspired me, and you seem to know a good deal about creating LED arrays.

https://www.rollitup.org/led-other-lighting/538173-cheapo-diy-chinese-led-grow.html

[url]https://www.rollitup.org/led-other-lighting/513853-home-made-led-grow-lights.html
[/URL]

 

[JMD]

How well would a setup using:

2x 100W 2700K leds: http://www.topledlight.com/100w-warm-white-high-power-led_p275.html
and
2x 100W 3200K cree leds: http://www.topledlight.com/100w-cree-xmlu2-led-multichip-100-watts-warm-white-light-9000lm-copper-plate_p1328.html

All running at 3amps for a total of about 400W work out. It should come out to something like 26000 lumens. Would I need to buy separate blues and reds still, or will these two warm white color ranges be sufficient. Should I just stick with the higher lumins cree 3200K leds, or stick with just the 2700K leds for better colors?

EDIT:
I don't mean to sidetrack your thread, but you've really inspired me, and you seem to know a good deal about creating LED arrays.

The first one is a cheap chinese LED. These have multiple strings in parallel, while the Cree is a single string driven at a high current.
I'd go for the Cree.

 

[Flame21]

What are the pros and cons of going with multiple 50 watt LEDs vs fewer 100 watt LEDs? I figured you'd have to buy fewer drivers and heatsinks if you stick with just the 100 watt ones. You seem to be looking at just the 50 watt ones JMD.

 

[JMD]

What are the pros and cons of going with multiple 50 watt LEDs vs fewer 100 watt LEDs? I figured you'd have to buy fewer drivers and heatsinks if you stick with just the 100 watt ones. You seem to be looking at just the 50 watt ones JMD.

The reason is that the 100W modules require 3A, while the 50W is only 1.5A - this makes the drivers quite a bit cheaper.



The harvest is still drying (in glass jars), but it looks tasty!

 

[Slipon]

look good

do you know if there is any down side of them 10/20/30/50W LED footlight ?



wondering if it wouldn't be more easy for me just to buy a few of them to add to my LED panel if I just want a bit more converges

 

[Bumping Spheda]

do you know if there is any down side of them 10/20/30/50W LED footlight ?

The reflectors in them seem really cheap to me (ime, they're not even outside the beam angle down at the chip, they let light leak a little behind the reflector, and no idea on their reflectance but I'll assume it's not stellar). The drivers are more than likely cheap, too. And then of course most of them use generic Chinese multichips.

That being said, overall, not bad at all for the price (after shopping around). You can usually find them for about $1/W on average. Perhaps a little less if buying from a trade site, most likely more when looking on eBay.

I think you can make something very similar yourself for about the same price using higher quality components, but you just might hang yourself in a tangle of wires if you're not careful.

 

[JMD]

look good

do you know if there is any down side of them 10/20/30/50W LED footlight ?

View attachment 2808964

wondering if it wouldn't be more easy for me just to buy a few of them to add to my LED panel if I just want a bit more converges

It's a very easy solution to use those flood light, but it's Chinese multi-chip LEDs, cheap Chinese drivers and cheap reflector and housing. With that said.. I'm sure it will work just fine.

 

[Slipon]

ok, well my biggest concern is the heat (if they don't have a fan ?)

what is the down side of multi chips ?

 

[Bumping Spheda]

Heat shouldn't be a problem, the heat sinks are properly sized per the wattage. The multichips are all the same size (30W, 50W, 100W) and yet the floods get bigger per the wattage in order to mitigate the heat.

Multichips are fine, imo. Some people don't like them for various reasons. They do pack a lot of Watts in a rather small amount of space so you tend to get hot spots of light similar to using multiple 600W HPS fixtures, or what have you. When using 1W or 3W chips you can space the LED's accordingly and arguably get more homogeneous light levels over your canopy. I think they are cool because they simplify the DIY process a lot, and if you have multiple wavelengths on the same multichip you get very even spectral mixing by having all the chips so closely packed together. Think Kessil where the light is evenly mixed by the time it leaves the reflector, whereas with 1W/3W LED's you might need the lights at 12in or so before those Blue hot spots that bleach your plants are "diffused" enough to not have negative effects. I guess this isn't really a selling point here considering we're discussing White multichips, but for the record, I guess. Also, most of the multichips you see use Chinese chips so you don't get quite as high efficiency when compared to boutique name brands. When I'm looking for a quality multichip I aim for the Red chips to be 42mil and the Blue chips to be 45mil. If the seller doesn't specify I usually guess they're 35mil and those chips aren't as efficient.

 

[JMD]

ok, well my biggest concern is the heat (if they don't have a fan ?)

what is the down side of multi chips ?

Down side is the lack of proper driving. If one chip dies, the rest will follow soon after (if you use a CC driver). If they use CV drivers, the issue might be too high current.