Best LED for a 2x4x5 tent. Looking to replace a 144x5 Mars Hydro Reflector

tinyplantas

Active Member
Yes, 1 pot + 1 resistor = 110K ohm resistance to make sure you're maxing the driver out at full power. Another way would be a switch that disconnects the pot when dimming isn't desires.

Best way to power 2 fans with 1 driver is parallel and 1 APV-12-12 should be able to handle 2 120mm fans.
Hi @Rahz, I got my order from Jerry super fast and have been assembling my light. I have a question regarding the dimmer. I have this pot:

http://www.amazon.com/gp/product/B009QFU9H4?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

Do I need a resistor, or can I just use the pot alone? @bizfactory mentioned something about if I go below 10% power it can damage the driver.
 

Rahz

Well-Known Member
That pot is a 10K ohm, so if you hook your driver to it it will only allow the driver to output 10% of it's max current. You need a 100K ohm pot.

The Meanwell drivers we generally use don't allow the current to drop past 10% so you don't need to worry about turning a pot down too low, though there may be drivers that don't have the same protections. The main reason for using a resistor is that pots don't provide an exact range. A pot may provide +-10 or +-5 % of it's rating, so at max a pot might provide 105K ohms of resistance, or 95K ohms of resistance. It's a grab bag and if you happen to get a pot that will only provide 95K ohms then you're loosing 5% of your drivers output. Adding a 10K ohm resistor in the loop adds to the total resistance, so 95+10 = 105K ohms of resistance and assures the drivers current is being maxed out when you turn it all the way up.
 

Humanrob

Well-Known Member
I have a light with 8 Cree 3070-series COBs ((2) 5000k, (2) 4000k, (4) 3000k) in my 4x2 tent. Last run I vegged under the 4's and 5's (200w), and flowered under the 4's and 3's (300w). I had two plants in there that were vegged for 7 weeks, and they filled out the tent. This next run I'm going to leave the 5's on in flower, so I'll be flowering with the full 400w.

It's a shame, but I won't have any comparative data between using 300w or 400w in a 4x2. First, I lost the entire aforementioned crop to PM. Epic clusterfrack. And this time I'm going with either 3 or 4 plants in the space instead of 2. All I can say is PM aside, 300w in a 4x2 grew some really big girls with large beautiful buds. My compost pile is probably way stoned about now.

Sounds like with your set up, you'll be rockin' it.
 

Rahz

Well-Known Member
Thanks @Rahz appreciate the clarification. So the wiring would go Dim positive, resistor, pot, dim negative?
Yes exactly. The resistor can go before or after the pot.

Regarding your other question it looks like Greengenes has confirmed the solution.
 

tinyplantas

Active Member
...a ring connector that fits the AC wire gauge you're using for a redundant ground....
I just want to clarify the exact procedure for grounding my light. Do I need to split the ground wire coming out of the meanwell driver and screw it to one of the heatsinks with a ring connector, or is it enough to just attach a grounded power cable to the meanwell and screw the driver into the aluminum framing?
 

Rahz

Well-Known Member
The sink is anodized so the screws may not make a good connection. There are ground pads on the underside of the driver but they may not make contact depending on how the driver is mounted. In any case I would split the ground and secure it to the sink, just to be safe.
 

tinyplantas

Active Member
Wooohooo! Got her all built and wired up. Still have to go get a potentiometer and add that in but it works, I have created light!

Thanks @Rahz @bizfactory @REALSTYLES @zangtumtum and everyone else who has offered such awesome advice throughout this process, I truly appreciate it. Can't wait to hang it over my ladies in a day or so once I get the pot in there.

Does anyone have any tips for wiring the resistor to the pot, should I get some sort of little box or something to contain it?

IMG_2279.JPG IMG_2280.JPG IMG_2281.JPG
 

tinyplantas

Active Member
@Rahz I just had a thought, since I bought a 10k potentiometer by accident, could I get a 100k resistor and wire them together for the same result as a 10k resistor + 100k pot, or am I not understanding how it works correctly?
 

tinyplantas

Active Member
I have a light with 8 Cree 3070-series COBs ((2) 5000k, (2) 4000k, (4) 3000k) in my 4x2 tent. Last run I vegged under the 4's and 5's (200w), and flowered under the 4's and 3's (300w). I had two plants in there that were vegged for 7 weeks, and they filled out the tent. This next run I'm going to leave the 5's on in flower, so I'll be flowering with the full 400w.

It's a shame, but I won't have any comparative data between using 300w or 400w in a 4x2. First, I lost the entire aforementioned crop to PM. Epic clusterfrack. And this time I'm going with either 3 or 4 plants in the space instead of 2. All I can say is PM aside, 300w in a 4x2 grew some really big girls with large beautiful buds. My compost pile is probably way stoned about now.

Sounds like with your set up, you'll be rockin' it.
Hey thanks man! Sorry to hear about the PM issues, I haven't experienced any pests before and I really hope I never do. Have any pics of your setup? I couldn't find them in your history.
 

Rahz

Well-Known Member
@Rahz I just had a thought, since I bought a 10k potentiometer by accident, could I get a 100k resistor and wire them together for the same result as a 10k resistor + 100k pot, or am I not understanding how it works correctly?
It would only dim from 110-100, so basically wouldn't dim at all.
 

Rahz

Well-Known Member
Does anyone have any tips for wiring the resistor to the pot, should I get some sort of little box or something to contain it?
You can solder the resistor between some wire and fold and secure the wire to keep the resistor safe and connect the wire as normal.

resistor.jpg
 

benbud89

Well-Known Member
Would you please wanna upload a picture of how you ended doing your grounding? It is one of my worries with my light, since Im definitely no electrician. My lamp is going to look a lot like yours, Im also using cxb 3590, 8 pieces for a 4x2. I only decided to go with the c1400 drivers, because I got sick and tired of my current setup.
 

Humanrob

Well-Known Member
Hey thanks man! Sorry to hear about the PM issues, I haven't experienced any pests before and I really hope I never do. Have any pics of your setup? I couldn't find them in your history.
I think I've now had every issue there is... lol. I was on my fourth indoor grow and I had never had any issues with PM indoors before, and it just wasn't on my radar at all. It came on fast and hard during flower, there was no stopping it... but I did learn a few things and it won't happen again.

My light is brutally ugly and crude, not much to look at. I tend to overbuild and use materials I'm familiar with which is sometimes less than optimal. I built it with a big idea, that it be able to change size in length and width to fit different spaces. To that end I used drawer sliders for my COBs on the long sides. Those are still in play, but recently I disassembled and completely rebuild and rewired the whole thing, and I made it rigid front to back.

I just started a run, so I have the 4000's and 5000's on, and you can see its about 3.5' above the babies. It's really easy to burn babies with these lights. (I have all of the cobs on dimmable drivers, but have not hooked up the potentiometers yet.) The two 5000's are on a unit that can be separated from the other part, in case I want to use it separately in a veg space. Anyway, sorry for the long explanation, but here are some quick pics...
 

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tinyplantas

Active Member
Would you please wanna upload a picture of how you ended doing your grounding? It is one of my worries with my light, since Im definitely no electrician. My lamp is going to look a lot like yours, Im also using cxb 3590, 8 pieces for a 4x2. I only decided to go with the c1400 drivers, because I got sick and tired of my current setup.
Sure, you can see in the pics I posted but here is a close up. I split the green ground wire from the driver into 2 with an ideal 3 way connector (the orange one). One goes to the ground wire in the power cable, the other goes to a ring connector that I screwed into the heatsink.


IMG_2282.JPG IMG_2283.JPG
 

tinyplantas

Active Member
Got my light all set up in the tent. Going to have to take it out in a few days once the potentiometer arrives. I would've installed it today but the only one I could find locally was at radioshack and it was a stereo volume pot with two inputs so I ordered one on amazon and am waiting for it to arrive.

Besides all the efficiency and power these lights offer, the number one thing I'm excited about is being able to see my plants in their actual colors instead of under that blurple bs.


IMG_2287.JPG IMG_2288.JPG IMG_2289.JPG IMG_2290.JPG IMG_2291.JPG
 
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