Designing and Building a LED Fixture

xpistalpetex · 07-10-2009, 01:50 AM

hey hoppy if possible can you do a step by step wiring?

**Hoppy** · 07-10-2009, 04:36 AM

Quote:

Originally Posted by xpistalpetex

hey hoppy if possible can you do a step by step wiring?

Yes, I probably can, but I don't have a photo that shows the wiring well. Let me see if I can work up a drawing that will be clear.

xpistalpetex · 07-10-2009, 09:16 AM

ooo thank you sir

**Hoppy** · 07-11-2009, 03:29 AM

Step by step wiring:
1. Having attached all of the LEDs to the heatsink, making sure they are lined up with the positive ends facing the right direction - towards where the positive lead from the power will come, solder the LEDs into two series chains of 12 each, using short pieces of insulated wire. Connect negative end to next positive end, etc.

2. Attach IC Voltage Regulator, a tiny little thing, to the heatsink with a electrical isolation pad between it and the heatsink, and an electrical isolation bushing in the Voltage Regulator mounting hole.

3. Solder a 47 or 100 microfarad capacitor, preferably one that doesn't have a positive and negative lead, across the "Vout" and "Adj" terminals of the Voltage Regulator.

4. Select the current setting resistor, by dividing 1.25 by the desired current (twice the current per LED, since this will be for two parallel circuits.) Pick the closest standard resistor to the value you determined. Solder one lead from each resistor together, to put them in a series string.

5. Solder the connected ends to one end terminal of the DPDT switch (SPDT works fine).

6. Solder one of the remaining resistor leads to the other end terminal of the DPDT switch.

7. Solder the other remaining resistor lead to the "Adj" terminal of the voltage regulator.

8. Solder a wire connecting the center terminal of the DPDT switch to the "Vout" terminal of the voltage regulator.

9. The 48 volt DC power adapter has a row of pins at one end - 6 as I recall. Solder a wire from the second or third of those pins to the "Vin" terminal of the voltage regulator.

10. Solder two long lengths of wire together at one end, and solder that connected pair to the "Adj" terminal of the Voltage Regulator.

11. Solder the other end of one of those long wires to the first positive solder pad on the first in the string of LEDs. Solder the other end of the other long wire to the other first positive solder pad on the other string of LEDs.

12. Solder short wires to the negative solder pads of the two end LEDs in the two strings, and connect them to a grounding screw in the heat sink.

13. Solder a ground wire to the ground terminal of the 48 VDC power adapter, and attach the other end to a grounding screw on the heat sink.

14. Solder the green ground wire of the 120 VAC power cable to the ground terminal on the 48 VDC power adapter, or attach it to the grounding screw on the heat sink.

15. Connect the black and white wires of the 120 VAC power cable to the power in terminals on the 48 VDC power adapter.

16. Wiring is complete. Double check your fire insurance before plugging this in the first time

**VisionQuest28** · 07-11-2009, 03:15 PM

Man, im so intrigued by this idea and LED lighting in general. I would love to put one of these together, but i think, scratch that... i know, i would be in WAAAAAAY over my head. I just dont think i could afford to learn as i go and pay to replace the things i messed up! I am searching out and buying the LED light strips made by current called PowerBrite's for a 10 gallon im setting up. Just got one on ebay for about $30, would like one more main unit and then i need to find the linking modules. Think im gonna end up with an intensely lit tank in the 16w range...im excited!

But what i would really like to do is set up LED's on the 36 gallon corner bowfront i have. Was planning on doing MH lighting, mainly because its such an odd shaped tank its hard to get an even spread of light. As soon as i saw this thread i started thinking about using LEDs on that tank. If i had the know how i would put one of these together in the shape i needed. But since i dont ive been looking at some of the already made LED panels on ebay mostly. The price is about equivalent to buying MH, maybe even a little less, especially when you consider electric costs and heat issues. Im just hesitant because i dont know if the panels would provide the right color temp/spread/and intensity im looking for.

I guess my point to all of this is.... you the man Hoppy! Such a cool DIY! I agree that LEDs are the future of lighting, and you got in there on the ground floor. Way to go!

**Hoppy** · 07-11-2009, 06:24 PM

Quote:

Originally Posted by VisionQuest28

Man, im so intrigued by this idea and LED lighting in general. I would love to put one of these together, but i think, scratch that... i know, i would be in WAAAAAAY over my head. I just dont think i could afford to learn as i go and pay to replace the things i messed up! I am searching out and buying the LED light strips made by current called PowerBrite's for a 10 gallon im setting up. Just got one on ebay for about $30, would like one more main unit and then i need to find the linking modules. Think im gonna end up with an intensely lit tank in the 16w range...im excited!

But what i would really like to do is set up LED's on the 36 gallon corner bowfront i have. Was planning on doing MH lighting, mainly because its such an odd shaped tank its hard to get an even spread of light. As soon as i saw this thread i started thinking about using LEDs on that tank. If i had the know how i would put one of these together in the shape i needed. But since i dont ive been looking at some of the already made LED panels on ebay mostly. The price is about equivalent to buying MH, maybe even a little less, especially when you consider electric costs and heat issues. Im just hesitant because i dont know if the panels would provide the right color temp/spread/and intensity im looking for.

I guess my point to all of this is.... you the man Hoppy! Such a cool DIY! I agree that LEDs are the future of lighting, and you got in there on the ground floor. Way to go!

When the question about lighting a bowfront, 24" on a side, came up I started to see if it could be done reasonably. Here is the layout that I figured would give enough light for most plants, but I didn't go ahead with figuring out a circuit for this.

This would use the same 3" x 1" aluminum channel I used for mine, for a heat sink. If you want to look into it some more I could go ahead and figure out a good circuit.

4f1hmi · 07-11-2009, 06:37 PM

Thank you Hoppy for your very informative thread.

**VisionQuest28** · 07-11-2009, 11:30 PM

Quote:

Originally Posted by Hoppy

When the question about lighting a bowfront, 24" on a side, came up I started to see if it could be done reasonably. Here is the layout that I figured would give enough light for most plants, but I didn't go ahead with figuring out a circuit for this.

This would use the same 3" x 1" aluminum channel I used for mine, for a heat sink. If you want to look into it some more I could go ahead and figure out a good circuit.

Im certainly interested, and thanks for showing that lay out for a bowfront. If it was a really involved thing, i would say hold off on any figuring for a circuit. Im a ways out from doing anything with this tank, as im still gathering other equipment. You made your own power supply for yours right? I think i would be willing to pay a little extra for an already available power supply, mainly because that would save me a lot of headache. I think i could work the rest out (assuming you'd be willing to hold my hand the whole way! lol) by myself or atleast know a person or two that might be able to help.

Did you do any playing around with different colored LEDs? I think if i remember right you went with all 10,000k right? And i rememeber you saying that you had thought about adding in red, but that it has unpredictable results sometimes. Could you explain that any more?

Id so love to be able to build this myself. I know th elevel of satisfaction you must feel is huge!

**Hoppy** · 07-12-2009, 12:17 AM

With 45 LEDs the "drivers" for the LEDs could cost quite a lot if you buy them, and you would still need a source of DC power. Given how simple it is to make your own "driver" circuit, and how cheap it is, it is well worth the struggle to do so.

I will work out some kind of circuit or circuits that will work with this, and you can decide for yourself if you want to tackle it.

I use all "cool white" Cree LEDs, which don't have a lot of red in their spectra. Theoretically you could mix cool white with warm white and get better color rendition, but I haven't tried it so I'm not sure how well the light from the LEDs would mix. Adding red LEDs is another possibility, but I already know from the experience of others that it is very hard to avoid seeing the red beams of light when you do that.

**VisionQuest28** · 07-12-2009, 12:30 AM

Ok, thats awesome, thanks. I can get my potential helper(s) to look it over and see what they think. Whats your opinion on the different optics that can be mounted over the LEDs? Would that be a way to get the different colors to mix better? Ive looked at some, when i was looking into adding a little bit of red to the 10g with powerbrites, and the prices didnt seem bad, but i wasnt thinking about 45 of them either.

**Hoppy** · 07-12-2009, 04:23 AM

Quote:

Originally Posted by VisionQuest28

Ok, thats awesome, thanks. I can get my potential helper(s) to look it over and see what they think. Whats your opinion on the different optics that can be mounted over the LEDs? Would that be a way to get the different colors to mix better? Ive looked at some, when i was looking into adding a little bit of red to the 10g with powerbrites, and the prices didnt seem bad, but i wasnt thinking about 45 of them either.

As best I can tell, all of the lenses made for LEDs are to get less spread of the light, so you can get more intensity at greater distances. But, our objective is to get wide spread of the light from each LED so they blend in and add to the total intensity at every spot in the tank. So, I wouldn't consider any optics at all.

Here is a diagram of one way to connect all of the 45 LEDs.

Finding the parts can be a challenge. The little IC Voltage Regulators are not widely available now, being considered obsolete, but also being perfect for this application. Many are still available, but it appears that you need to get a quote on the specific number you want from the seller. I googled to find out about this. Newark Electronics doesn't seem to carry them anymore.

The AC to 12 Volt DC adapters are sold for people to use to power their 12 volt accessories normally powered by their car power socket. So, they are pretty widely available, and ebay has several. They need to have about 5 amp capacity to avoid overheating with the continuous 3.5 amp current each will be supplying.

The 47 microfarad capacitors are standard parts that RadioShack and other stores carry. But, make sure they are not polarized - no + and - leads.

The single hardest part of this is mounting the voltage regulators, which are only 0.4 inch by 0.5 inch by 0.2 inch in size, onto the heat sink, and keeping the big mounting lug electrically isolated from the heat sink, but thermally connected to it. This means using a mica sheet between the lug and the heat sink, and a plastic bushing in the mounting hole. There are kits available with these parts: TO-220 mounting kits. Then soldering wires to the voltage regulator leads, which are close together, isn't easy either. But, all of the rest is fairly easy.

This circuit is designed to get 750 mAmps current for each LED. If one LED fails, the current to the remaining 12 LEDs in that group will increase to 940 mAmps, which is still within the limit for these LEDs.

And the LEDs are these: http://www.dealextreme.com/details.dx/sku.2395 or others in that series.

**VisionQuest28** · 07-12-2009, 05:34 PM

Hoppy...my head is spinning! And you make it all sound so easy. haha Ive spent the last several hours looking over stuff online, and i GUESS i have a little better understanding now.

That circuit diagram doesnt show the power supply, right, or does it? And the voltage regulators, capacitors, and resistors are what would make up a driver? The equivalent would be something like a BuckPuck?

And the way you're showing the LEDs obviously isnt the same as i would have them mounted. But as long as they are in 3 groups of 15, with 5 parallel strings of 3 LEDs in each group, i could follow that diagram, yes?

I said i was in over my head, and i think thats even more true than ever. But i would really like to figure this out. I remember you saying what an obsession this turned into for you, and i can certainly see how this would be true. Luckily for me (and anyone else who is thinking about doing this) you have laid the ground work to make this remotely possible for me to even consider doing. Thanks for that! And thanks for taking the time to help with what you have already!

**VisionQuest28** · 07-12-2009, 07:00 PM

never mind about the power source, thats what the 12 VDC adapter is, i got it. Given a little more time ill probably get my answer to the buckpuck too. But if you get here first.... haha

**Hoppy** · 07-12-2009, 08:22 PM

As best I can tell a buck puck is similar to the Voltage Regulator/Resistor/capacitor circuit. I suspect it is different, probably using transistors instead of the Voltage Regulator. In any case, yes the VR + Resistor + Capacitor serves the function of the buck puck, but a lot cheaper. And, if you haven't figured it out yet, that sketch isn't to scale. The 12 VDC adapters (power supplies) are about 1" x 2" x 4", while the Voltage regulator is closer to .5" x .4" x .15". They are much smaller than you will ever expect!

And, yes, I showed the LEDs in that configuration just to make the wiring look easier. In your case it will look different. The principles involved are not all that difficult to grasp, but I found it all to be non-intuitive, so I felt like a very slow learner trying to understand it.

**VisionQuest28** · 07-12-2009, 09:00 PM

From the time i last posted i just sat down and re-read this whole thread, and if i do this im definitely gonna spend the money on buck puck's or something similar. After seeing all the problems you had, the extra $40 or so to just buy it and be done with it seems SOOOO worth it me. I just dont think i have the knowledge or skill to do it the same way you did. But im still very interested in trying this. Even with buying parts instead of making them, the cost to benefit ratio still seems good to me.

07-11-2009, 03:29 AM	#289 (permalink)
Hoppy Planted Tank Guru (View User Tanks) PTrader: (22/100%) Join Date: Dec 2005 Location: Sacramento, CA Posts: 5,683	Step by step wiring: 1. Having attached all of the LEDs to the heatsink, making sure they are lined up with the positive ends facing the right direction - towards where the positive lead from the power will come, solder the LEDs into two series chains of 12 each, using short pieces of insulated wire. Connect negative end to next positive end, etc. 2. Attach IC Voltage Regulator, a tiny little thing, to the heatsink with a electrical isolation pad between it and the heatsink, and an electrical isolation bushing in the Voltage Regulator mounting hole. 3. Solder a 47 or 100 microfarad capacitor, preferably one that doesn't have a positive and negative lead, across the "Vout" and "Adj" terminals of the Voltage Regulator. 4. Select the current setting resistor, by dividing 1.25 by the desired current (twice the current per LED, since this will be for two parallel circuits.) Pick the closest standard resistor to the value you determined. Solder one lead from each resistor together, to put them in a series string. 5. Solder the connected ends to one end terminal of the DPDT switch (SPDT works fine). 6. Solder one of the remaining resistor leads to the other end terminal of the DPDT switch. 7. Solder the other remaining resistor lead to the "Adj" terminal of the voltage regulator. 8. Solder a wire connecting the center terminal of the DPDT switch to the "Vout" terminal of the voltage regulator. 9. The 48 volt DC power adapter has a row of pins at one end - 6 as I recall. Solder a wire from the second or third of those pins to the "Vin" terminal of the voltage regulator. 10. Solder two long lengths of wire together at one end, and solder that connected pair to the "Adj" terminal of the Voltage Regulator. 11. Solder the other end of one of those long wires to the first positive solder pad on the first in the string of LEDs. Solder the other end of the other long wire to the other first positive solder pad on the other string of LEDs. 12. Solder short wires to the negative solder pads of the two end LEDs in the two strings, and connect them to a grounding screw in the heat sink. 13. Solder a ground wire to the ground terminal of the 48 VDC power adapter, and attach the other end to a grounding screw on the heat sink. 14. Solder the green ground wire of the 120 VAC power cable to the ground terminal on the 48 VDC power adapter, or attach it to the grounding screw on the heat sink. 15. Connect the black and white wires of the 120 VAC power cable to the power in terminals on the 48 VDC power adapter. 16. Wiring is complete. Double check your fire insurance before plugging this in the first time __________________ Hoppy

07-11-2009, 06:37 PM	#292 (permalink)
4f1hmi Algae Grower (View User Tanks) PTrader: (8/100%) Join Date: Apr 2009 Location: south orange county Posts: 91	Thank you Hoppy for your very informative thread. __________________ BO - EHEIM PIMP # 378- Mission Viejo Proud SCAPE member Aim High

07-12-2009, 12:17 AM	#294 (permalink)
Hoppy Planted Tank Guru (View User Tanks) PTrader: (22/100%) Join Date: Dec 2005 Location: Sacramento, CA Posts: 5,683	With 45 LEDs the "drivers" for the LEDs could cost quite a lot if you buy them, and you would still need a source of DC power. Given how simple it is to make your own "driver" circuit, and how cheap it is, it is well worth the struggle to do so. I will work out some kind of circuit or circuits that will work with this, and you can decide for yourself if you want to tackle it. I use all "cool white" Cree LEDs, which don't have a lot of red in their spectra. Theoretically you could mix cool white with warm white and get better color rendition, but I haven't tried it so I'm not sure how well the light from the LEDs would mix. Adding red LEDs is another possibility, but I already know from the experience of others that it is very hard to avoid seeing the red beams of light when you do that. __________________ Hoppy

07-12-2009, 08:22 PM	#299 (permalink)
Hoppy Planted Tank Guru (View User Tanks) PTrader: (22/100%) Join Date: Dec 2005 Location: Sacramento, CA Posts: 5,683	As best I can tell a buck puck is similar to the Voltage Regulator/Resistor/capacitor circuit. I suspect it is different, probably using transistors instead of the Voltage Regulator. In any case, yes the VR + Resistor + Capacitor serves the function of the buck puck, but a lot cheaper. And, if you haven't figured it out yet, that sketch isn't to scale. The 12 VDC adapters (power supplies) are about 1" x 2" x 4", while the Voltage regulator is closer to .5" x .4" x .15". They are much smaller than you will ever expect! And, yes, I showed the LEDs in that configuration just to make the wiring look easier. In your case it will look different. The principles involved are not all that difficult to grasp, but I found it all to be non-intuitive, so I felt like a very slow learner trying to understand it. __________________ Hoppy

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07-10-2009, 01:50 AM	#286 (permalink)
xpistalpetex Algae Grower (View User Tanks) PTrader: (0/0%) Join Date: May 2008 Location: Westminster, CA Posts: 14	hey hoppy if possible can you do a step by step wiring?

07-10-2009, 09:16 AM	#288 (permalink)
xpistalpetex Algae Grower (View User Tanks) PTrader: (0/0%) Join Date: May 2008 Location: Westminster, CA Posts: 14	ooo thank you sir

07-11-2009, 03:15 PM	#290 (permalink)
VisionQuest28 Planted Tank Obsessed (View User Tanks) PTrader: (52/100%) Join Date: Apr 2007 Location: Ithaca, NY Posts: 418	Man, im so intrigued by this idea and LED lighting in general. I would love to put one of these together, but i think, scratch that... i know, i would be in WAAAAAAY over my head. I just dont think i could afford to learn as i go and pay to replace the things i messed up! I am searching out and buying the LED light strips made by current called PowerBrite's for a 10 gallon im setting up. Just got one on ebay for about $30, would like one more main unit and then i need to find the linking modules. Think im gonna end up with an intensely lit tank in the 16w range...im excited! But what i would really like to do is set up LED's on the 36 gallon corner bowfront i have. Was planning on doing MH lighting, mainly because its such an odd shaped tank its hard to get an even spread of light. As soon as i saw this thread i started thinking about using LEDs on that tank. If i had the know how i would put one of these together in the shape i needed. But since i dont ive been looking at some of the already made LED panels on ebay mostly. The price is about equivalent to buying MH, maybe even a little less, especially when you consider electric costs and heat issues. Im just hesitant because i dont know if the panels would provide the right color temp/spread/and intensity im looking for. I guess my point to all of this is.... you the man Hoppy! Such a cool DIY! I agree that LEDs are the future of lighting, and you got in there on the ground floor. Way to go!

07-12-2009, 12:30 AM	#295 (permalink)
VisionQuest28 Planted Tank Obsessed (View User Tanks) PTrader: (52/100%) Join Date: Apr 2007 Location: Ithaca, NY Posts: 418	Ok, thats awesome, thanks. I can get my potential helper(s) to look it over and see what they think. Whats your opinion on the different optics that can be mounted over the LEDs? Would that be a way to get the different colors to mix better? Ive looked at some, when i was looking into adding a little bit of red to the 10g with powerbrites, and the prices didnt seem bad, but i wasnt thinking about 45 of them either.

07-12-2009, 05:34 PM	#297 (permalink)
VisionQuest28 Planted Tank Obsessed (View User Tanks) PTrader: (52/100%) Join Date: Apr 2007 Location: Ithaca, NY Posts: 418	Hoppy...my head is spinning! And you make it all sound so easy. haha Ive spent the last several hours looking over stuff online, and i GUESS i have a little better understanding now. That circuit diagram doesnt show the power supply, right, or does it? And the voltage regulators, capacitors, and resistors are what would make up a driver? The equivalent would be something like a BuckPuck? And the way you're showing the LEDs obviously isnt the same as i would have them mounted. But as long as they are in 3 groups of 15, with 5 parallel strings of 3 LEDs in each group, i could follow that diagram, yes? I said i was in over my head, and i think thats even more true than ever. But i would really like to figure this out. I remember you saying what an obsession this turned into for you, and i can certainly see how this would be true. Luckily for me (and anyone else who is thinking about doing this) you have laid the ground work to make this remotely possible for me to even consider doing. Thanks for that! And thanks for taking the time to help with what you have already!

07-12-2009, 07:00 PM	#298 (permalink)
VisionQuest28 Planted Tank Obsessed (View User Tanks) PTrader: (52/100%) Join Date: Apr 2007 Location: Ithaca, NY Posts: 418	never mind about the power source, thats what the 12 VDC adapter is, i got it. Given a little more time ill probably get my answer to the buckpuck too. But if you get here first.... haha

07-12-2009, 09:00 PM	#300 (permalink)
VisionQuest28 Planted Tank Obsessed (View User Tanks) PTrader: (52/100%) Join Date: Apr 2007 Location: Ithaca, NY Posts: 418	From the time i last posted i just sat down and re-read this whole thread, and if i do this im definitely gonna spend the money on buck puck's or something similar. After seeing all the problems you had, the extra $40 or so to just buy it and be done with it seems SOOOO worth it me. I just dont think i have the knowledge or skill to do it the same way you did. But im still very interested in trying this. Even with buying parts instead of making them, the cost to benefit ratio still seems good to me.

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