Custom lm301b QB for micro box

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gorillaglueaaron

gorillaglueaaron

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Hi everyone,

I'm working on a design for a tiny grow box (10"x10"x10") and it's so small that I need to make a custom QB. LED strips don't come small enough and bulbs, which is what most people use for micro grows, definitely won't fit.

My light will be just under 8"x8" using 36 lm301b 4000k diodes in 9 rows of 4 in parallel. I've calculated the PPF to be about 25 using the lumens and spectrum of the individual LEDs. This will give me an average of about 350ppfd which for a micro grow isn't too bad.

I'm waiting on the diodes at the moment which should be arriving in the next few days. I'll post updates as I'm building it.

Here is what the spectrum will be:

Spectrum of light


I had the option between this or 3000k but I figured in a micro grow, I could use more blue light to keep the plant short.

I've heard it all already. "You're not going to be able to grow anything that small"

For anyone wondering why I'm doing this, it's 100% for fun. I don't expect to get anything good out of it.


GGA
 
gorillaglueaaron

gorillaglueaaron

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So it turns out, the star boards I ordered are too big for the diodes and Digikey doesn't have any that will fit mine so I have to return them and order blank ones to design my own.
 
gorillaglueaaron

gorillaglueaaron

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I assume small cob or cfl is not an option?
Cfl no way. I considered cobs but I decided to use individual diodes because cobs would be too focused and I'm going to have the plants growing really close to the lights. Also, since the plants are going to be so close, I wanted the most efficient LEDs as possible to prevent heat.
 
Goblinkiller

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I see. I could not find it now, but for some time ago I saw a diy tiny growbox on y ewtube. This one used led strips that was controllable with app on Phone. There were top light and side light. Worked brilliantly. I see you wrote that led strips is not strong enough?
 
gorillaglueaaron

gorillaglueaaron

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I see. I could not find it now, but for some time ago I saw a diy tiny growbox on y ewtube. This one used led strips that was controllable with app on Phone. There were top light and side light. Worked brilliantly. I see you wrote that led strips is not strong enough?
There are 2 types of LED strips.
The strips people use to light up the bottoms of cars, behind TVs... the ones that come with a controller and all that. Those are made with bad LEDs, are way too expensive for what they are and definitely aren't strong enough.
Then there are grow light LED strips that are just a row or 2 rows of LEDs and just come with the LEDs. These are what I wanted to use but they are too big for my space.
 
Moe.Red

Moe.Red

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There were top light and side light.

I believe you will find lighting from the side to be a pretty big waste. I don't believe undersides of leaves can use sunlight. I read about some testing on this and all it really did was use more energy and add heat. I can find that again if you are thinking about coming down the sides.

What star board design are you looking at? 1 Diode per board or an array?

If you get stuck I can help you design a custom PCB and get them printed at Osh Park I've used them many times for prototypes - you can order small qty of custom boards and takes about 2 weeks.
 
gorillaglueaaron

gorillaglueaaron

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I believe you will find lighting from the side to be a pretty big waste. I don't believe undersides of leaves can use sunlight. I read about some testing on this and all it really did was use more energy and add heat. I can find that again if you are thinking about coming down the sides.

What star board design are you looking at? 1 Diode per board or an array?

If you get stuck I can help you design a custom PCB and get them printed at Osh Park I've used them many times for prototypes - you can order small qty of custom boards and takes about 2 weeks.
I ordered 1 diode boards but I wasn't aware there were different sizes of diodes so I just ordered what looked like the one that would fit me best.

I'm just going to solder the diodes onto plain star boards (1 diode per board). I don't see why I didn't think of this before. It'll only cost me $15 for all the boards rather than premade star boards for $30 total or even more than that for a pcb. Thanks though.
 
Moe.Red

Moe.Red

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Screen Shot 2021 01 15 at 82545 AM


Another option, I think this will get you more light in less space than single star boards. You can cut off the tabs with the connectors they are not necessary if you hard wire these.
 
gorillaglueaaron

gorillaglueaaron

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View attachment 1079458

Another option, I think this will get you more light in less space than single star boards. You can cut off the tabs with the connectors they are not necessary if you hard wire these.
I thought about doing multi diode boards but then I'm going to get the same problems as with cobs (wait now that I think about it, this is a cob). I'm trying to disperse the light evenly so if I had something like this then I would have a few of these groups of LEDs instead of one sort of uniform intensity. It sort of seems weird since the space is so small but what I'm going for is coverage.
 
Moe.Red

Moe.Red

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Yeah, I would modify those boards and saw off the tabs with a band saw so you could put them all right next to each other. Higher light density. But in your case I get it, probably too much light.

That's why I always seem to design my own boards for stuff like this, you could make yourself the perfect 8x8, 36 diode PCB as one unit. Spread the diodes out exactly as you want them to be. Essentially you would be making a custom spider farmer type light.

But I'm an electrical engineer at heart and I always overthink stuff like this.
 
gorillaglueaaron

gorillaglueaaron

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This is what I was thinking:
I'm using a 12v 8.2A driver
Those red, black and gold things are 2ohm resistors.
Sorry, I don't know how to make a proper schematic so I just sketch these things out.
LED light
 
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gorillaglueaaron

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My diodes are now arriving on the 19th but I ordered some from digikey with my new star boards because they were really cheap there and if I get some extras I can start experimenting before I get the real ones. The digikey ones should be arriving tomorrow or the next day. My last order from them took less than 18 hours from Chicago to Toronto.
 
gorillaglueaaron

gorillaglueaaron

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So, I'm curious. Why so small? I'm really interested in seeing what you do at this scale.
I'm challenging the limits. Seeing the smallest I can go. I was thinking about building something small but much bigger than this for a mother so I could do SOG in my actual tent but then I saw other people's boxes and just wondered how small was the smallest possible. I'm hoping I can even grow something in it because it's put me back a decent amount already, almost as much as a 2x2x4 set up would be.
 
gorillaglueaaron

gorillaglueaaron

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You should get one of these....perfect for a micro grow.

That probably would have been a good idea. Oh well, now I get to learn to do it myself.
+This way I got to choose the spectrum.
 
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Sice

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Yea you can grow micro. Depending on genetics Ive gotten more than an ounce per plant (3 plants fit in the cabinet) under like 90-150 watt using EB3 Slims. I did not do a grams per watt comparison since plants were at different stages. Newer LED lights can definitely make things happen.

See below a space of 22 x 12 x 14 inches
 
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