diy pc grow slightly different. (concept)

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panast

Member
The reason I say concept is because at this point it's still just an idea in my head.

But anyways, using something similar to this: https://youtu.be/GK0gzaQDb

Re-purpose a pc power supply and tie it into some led drivers/leds(not sure whether cobs or smaller bulbs would suit better) and also run intake/exhaust fans from the same supply.

Any pro opinions on this idea?
 
heckler73

heckler73

Well-Known Member
I'm doing it right now.
Feeding four, 12V bucks, on a single 12V rail (<40W total) of an old Dell ATX I salvaged.
Cost, $0.

No flicker, nothing weird, component temps pass the finger test. Everything seems to be running okay so far.:mrgreen:
 
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panast

Member
Nice. Wouldn't happen to have like instructions or parts list by chance? I did find a 2 yr old thread about this idea on icmag, with the use of resistors in a string, which is kinda foggy to me.

I understand the concept and am familiar with solder and what not. The only foggy areas to me is having an idea is suitable leds and their wattage.

12v bucks(buck converter?). Explanation?
I just figured tie the psu right into an led driver then the leds to the driver? All still pretty new to me so any clarification would be much appreciated.
 
heckler73

heckler73

Well-Known Member
panast said:
12v bucks(buck converter?). Explanation?
I just figured tie the psu right into an led driver then the leds to the driver? All still pretty new to me so any clarification would be much appreciated.
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Well, I suppose one could hook up a 12V 10W LED straight to the rail, but I suspect it will cause some problems. Have you read the Wikipedia entry on switched-mode power supplies? I'd be concerned about beat frequencies developing, which could cause the LEDs to flicker or dim mysteriously. That's only a hypothesis, though, based on some of my experiences with putting systems in parallel.

The Buck provides steady current (which is what we sort of want with driving LEDs, generally). It is regulating the supply to the LEDs. They are normally sold as 10W LED Drivers and the ones I am using are based on the PT4115 chip (look up the data sheet).

To further complicate the matter, I am also using IRF530 MOSFETs as switches to the supplies (for a future modification), mounted on a proto-board, taking the 5V supply from the ATX and using it as a "switch" signal on the gates.
That's what I like about the ATX supply in this case; it literally powers everything, from controls to fans to lights. The only thing not powered is the air pump for my μDWC, but I bet I could figure out a way to hook that up, too!

And they are ubiquitous. No need to wait for a replacement from China, just go to the local elex recycler and get a "new" one. :mrgreen:

I just made sure to have extra bucks and LEDs on hand. Something will fail down the road, but those parts were cheap. Those damn supplies can get expensive if one chooses the "classier" route to DIY.
You can see that when the CREE Gang in the LED section toss numbers around. It reminds me of the old audiophiles and their hyper-tech stereo systems. If one can spend the money on quality, then go ahead. But if what needs to be done, can be done for less, then why not? In the case of μ-cabs, one doesn't need much.
My 40W system cost ~$10, thanks mostly to clever auctioneering and salvaging.
Will I get more than $10 of joy from it? Probably...I just need some good genetics ;)
 
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panast

Member
heckler73 said:

Well, I suppose one could hook up a 12V 10W LED straight to the rail, but I suspect it will cause some problems. Have you read the Wikipedia entry on switched-mode power supplies? I'd be concerned about beat frequencies developing, which could cause the LEDs to flicker or dim mysteriously. That's only a hypothesis, though, based on some of my experiences with putting systems in parallel.

The Buck provides steady current (which is what we sort of want with driving LEDs, generally). It is regulating the supply to the LEDs. They are normally sold as 10W LED Drivers and the ones I am using are based on the PT4115 chip (look up the data sheet).

To further complicate the matter, I am also using IRF530 MOSFETs as switches to the supplies (for a future modification), mounted on a proto-board, taking the 5V supply from the ATX and using it as a "switch" signal on the gates.
That's what I like about the ATX supply in this case; it literally powers everything, from controls to fans to lights. The only thing not powered is the air pump for my μDWC, but I bet I could figure out a way to hook that up, too!

And they are ubiquitous. No need to wait for a replacement from China, just go to the local elex recycler and get a "new" one. :mrgreen:

I just made sure to have extra bucks and LEDs on hand. Something will fail down the road, but those parts were cheap. Those damn supplies can get expensive if one chooses the "classier" route to DIY.
You can see that when the CREE Gang in the LED section toss numbers around. It reminds me of the old audiophiles and their hyper-tech stereo systems. If one can spend the money on quality, then go ahead. But if what needs to be done, can be done for less, then why not? In the case of μ-cabs, one doesn't need much.
My 40W system cost ~$10, thanks mostly to clever auctioneering and salvaging.
Will I get more than $10 of joy from it? Probably...I just need some good genetics ;)
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Totally lost me at MOSFET I'm pretty noob lol. Just basic said soldering knowledge and how to wire series to a driver. Which YouTube taught me. Only thing I ever made before was a ballast that held 8cfls tied in series connected to an extension cord I stripped.

What leds do you run? I've already got the cree suggestions and looked into that, full parts would be well over $100 unless there is a cheaper place to buy them I don't know about lol.
Not 100% familiar with the model numbers or searching them yet tho. Like the vero equivalent of a cxa/b 2530 which are the ones suggested to me, no idea how to find then really lol.
 
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heckler73

heckler73

Well-Known Member
panast said:
Totally lost me at MOSFET I'm pretty noob lol. Just basic said soldering knowledge and how to wire series to a driver. Which YouTube taught me. Only thing I ever made before was a ballast that held 8cfls tied in series connected to an extension cord I stripped.
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If you followed it up to the MOSFETs, you're good to go. :D

What leds do you run?
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The cheapest, nastiest, most likely to fail possible. :lol: I look for "12V 10W LEDs" on Ebay and start bidding.
 
heckler73

heckler73

Well-Known Member
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panast

Member
heckler73 said:
It looks interesting. Those modular boards might be convertible themselves. But what's the thermal management like? I can't see much in those pics.
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No idea. Would need directions to convert them as I'm not familiar with that too much. I figured if I took those boards out I could mount aluminum for a heat sink. I found an old gun safe I could use instead of the pc I was thinking about. Is a pretty cheap one made out of maybe 1/8in metal. Assuming steel but not sure. Figure if I mount aluminium straight to the metal it will help some heat transfer and also maybe keep some warmth in the box as I'm not sure how much heat the leds will provide.
 
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panast

Member
So using a new cab with the upper lower chambers both 27h×9dx21w. Would 4 cxa2530 be ok for that space?

I think an hlg 185 700 at like 143v output would work for each chamber but I'm not completely sure and kinda having a hard time finding help or info that could clear it all up for me.

Idk if there would be a better driver or if I should use multiple drivers. Anyone at all that could throw out some advice I'd appreciate it greatly.
 
heckler73

heckler73

Well-Known Member
panast said:
So using a new cab with the upper lower chambers both 27h×9dx21w. Would 4 cxa2530 be ok for that space?

I think an hlg 185 700 at like 143v output would work for each chamber but I'm not completely sure and kinda having a hard time finding help or info that could clear it all up for me.

Idk if there would be a better driver or if I should use multiple drivers. Anyone at all that could throw out some advice I'd appreciate it greatly.
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So you're giving up on your original idea ? That's too bad, I was hoping to see another Hobo Grow on here. Well, if you want to be like everyone else, then start going through the LED forum. They have probably answered your question a dozen times over...just in the last week :mrgreen:
 
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panast

Member
heckler73 said:
So you're giving up on your original idea ? That's too bad, I was hoping to see another Hobo Grow on here. Well, if you want to be like everyone else, then start going through the LED forum. They have probably answered your question a dozen times over...just in the last week :mrgreen:
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I'd totally do the cheapo Chinese ones too. Just need driver advice to hook it all up. I had 5 3000k and 5 4000k in my cart. I figured maybe I could get better advice on cree mats.

Haven't bought anything yet as I don't want to waste money and have something not be the right part. So I've been trying to get as much help as i could.

I still may end up using my pc psu as I believe I have 2 sitting around 1 generic and 1 is like 500w. Just need to find some leds and figure out the bucks also.

I just have a thousand questions I feel like, and trying not to be a huge burden with them.
 
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panast

Member
Like for example. Do you have any problems with how the cheaper ones are wired internally? Like the diodes are series or parallel in the chip? Is there a bad failure rate or they do alright?
 
P

panast

Member
panast said:
Like for example. Do you have any problems with how the cheaper ones are wired internally? Like the diodes are series or parallel in the chip? Is there a bad failure rate or they do alright?
Click to expand...
I looked through a post that u had your build posted. How many watts/sqft did u end up with? It's hard to find size comparisons to other builds outside of yours and i think a guy name positivity had a small build with 3070s.
 
heckler73

heckler73

Well-Known Member
panast said:
Like for example. Do you have any problems with how the cheaper ones are wired internally? Like the diodes are series or parallel in the chip? Is there a bad failure rate or they do alright?
Click to expand...
That's why you need to pay attention to the specs. I've seen the 10W, 30V models and sat there scratching my head trying to figure out why they would wire them like that.
I almost bought them by accident, too.

panast said:
I looked through a post that u had your build posted. How many watts/sqft did u end up with
Click to expand...

I believe it works out to ~32W (4 different COBs) based on bench testing. I never actually bothered to check them in circuit :mrgreen: The plant is literally growing in ~1 sq.ft. so it is what it is.
I just saw a few hairs popping out last night, and they are coming in nicely now. I'm still looking out for balls, though. Could be a hermie.

out of the box.png
 
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panast

Member
4 10w each run by it's own 12v buck all wired into 1 12v rail?

I like that setup. Do straight 12 from pop?

So i need to make sure the cheap ones are 10-12v fv not 30-34 right? I would totally quote all neat like you do but I haven't quote figured that out yet lmao
 
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panast

Member
Something interesting I found while searching for different leds just now.

http://m.ebay.com/itm/3w-5w-10w-20w-30w-50w-100w-UV-Ultra-Violet-High-power-LED-Chip-395nm-F-Aquarium-/321776680835?_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20150519202348%26meid%3Dc759690134584b5a87234101e206693b%26pid%3D100408%26rk%3D3%26rkt%3D25%26mehot%3Dpp%26sd%3D321757548210&_trksid=p2056116.c100408.m2460&varId=510689859092

Wonder if that could replace the reptisun bulb I was thinking about. Sure would save a ton of space.
 
heckler73

heckler73

Well-Known Member
panast said:
4 10w each run by it's own 12v buck all wired into 1 12v rail?
Click to expand...
Yup...for example, I know my ATX supply can put out 16A @ 12V , but it has four channels. So each channel can handle 4A. Ergo, I can put 4 COBs on each rail, comfortably, with some headroom. Different supplies will vary in their handling, but for the most part, it is fairly common from my observation.

I like that setup. Do straight 12 from pop?
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I don't know, but the idea of doing that causes me to pause. I don't expect it would "pop" but it is more open to the problems associated with the ATX noise, ripple, etc. Those little gold wires can blow quite quickly if taken too far out of their operating range. Bucks provide the buffer.

So i need to make sure the cheap ones are 10-12v fv not 30-34 right? I would totally quote all neat like you do but I haven't quote figured that out yet lmao
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Well, it depends on your buck. But think about that wiring scheme, 12V chips will be likely 3 strings of 3, each running at ~300mA, while the 30V version is slapping 9 in series. Any spike in current will be relatively magnified 3x over on the series string (or 1/3 on the parallel strings). I found the 12V chips are cheaper (for now), and the bucks are available all over (because it is a common setup). Each buck and chip combo should come out to around $3 if you hunt carefully.


As for that link you posted, he's actually the guy I've bought a large chunk of parts from. He's terrible on the email, though. If your package is late (1 out of 10 times) you'll probably get a refund when you file a request. Then you'll probably get the package, still. :lol: I don't know if it's because he doesn't handle English communication well (then who's writing the ads?) or if he just doesn't give a shit and would rather have the customer be that happy.

To quote, just highlight the text you're interested in, and a little ghost button will show up saying "reply", click it and it will transfer the text to the window.
 
P

panast

Member
heckler73 said:
Yup...for example, I know my ATX supply can put out 16A @ 12V , but it has four channels. So each channel can handle 4A. Ergo, I can put 4 COBs on each rail, comfortably, with some headroom. Different supplies will vary in their handling, but for the most part, it is fairly common from my observation.
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Do you wire the bucks in series with the lights? Kinda confused I guess.
I pictured 1 12v rail to a splitter, off the splitter 4 bucks wired to a separate light each one instead of any strings in series?

But if you were to split it like that then you would split your 12v 4 ways right?

heckler73 said:
Well, it depends on your buck.
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I watched a video a guy used this http://m.ebay.com/itm?itemId=252221725170 to run a 12v 10w led. Is this something that would work? Accepts 4-40v input and 1.25-37v output.
 
heckler73

heckler73

Well-Known Member
panast said:
Do you wire the bucks in series with the lights? Kinda confused I guess.
I pictured 1 12v rail to a splitter, off the splitter 4 bucks wired to a separate light each one instead of any strings in series?

But if you were to split it like that then you would split your 12v 4 ways right?
Click to expand...
Yes... That is how I am doing it. I have the protoboard acting as the splitter, and each buck has its own feed from the board (post-MOSFETs), but only one 12V rail supplies the board.
 
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