Author Topic: Using High Power LEDs to Make Lights  (Read 5020 times)

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Offline WooferHound

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Using High Power LEDs to Make Lights
« on: November 05, 2018, 07:57:44 am »
I had found a few videos on YouTube about using High Power LEDs to make all kinds of lights. So I went on eBay and found this listing for LEDs from 1 to 100 watts.

https://www.ebay.com/itm/High-Power-1W-3W-5W-10W-20W-30W-50W-100W-White-SMD-LED-COB-Chip-Lights-Beads/122044236962?hash=item1c6a6744a2:m:mrwPJXkCqGpBSWx5zzsnzvA&var=421059306307

The prices were amazing, Shipping is free, and the seller was in California instead of China. Purchased a Lot of these and it only came out to $25 total. Be sure to click through to his Store and look at all of his LED products.

LEDs are powered at a certain Current, so a current limiter is needed to to use them. I found these Buck Converter Voltage Regulator/Current Limiters on eBay for $2 each, so I got 10 of them to play with. Perfect for powering LEDs from my 12 volt Solar Power system. They are rated at 5 amps but aren't stable above about 3 amps. The Output is a bit noisy so some additional filtering is helpful but not necessary.

https://www.ebay.com/itm/5pcs-XL4005-5A-DC-Buck-Step-Down-Voltage-Converter-Constant-Current-Power-Module/142632518904?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649



Small LEDs on the left are 1-3-5 watts. They look identical and I need to keep them in their packets until they are needed or they will get mixed up. The LED on the big heatsink top-right is a 10 watt. The Large LED bottom-right is a 20 watt. Buck Converter at the bottom.

I've been playing around with this stuff for about 3 weeks now and I'm very impressed.

First thing is, they get very hot. Assume that all the power that you put into them will come out as heat, a heatsink is required for anything over a minute. I have been gluing them down to heatsinks using 5-Minute Epoxy with very good results, the LED must be pressed down firmly to squeeze out the glue and get good thermal contact with the heatsink. I have had much better results using CPU Coolers, small heatsinks with a 12 volt fan attached. The fan gets the 12 volt directly while the LEDs are powered through the Current Regulator. Using a resister inline with the fan will slow it down and make it quieter. A small heatsink is fine for the 1 and 3 watt LEDs but a fan is needed for ratings 5 watts or more because the heatsink would need to be so too big.

The LEDs come in 4 versions of White . . .
Warm 3000-3500
Natural 4000-4500
White 6000-6500
Cool 10000-15000
I've tried the Warm and the Natural versions. The "warm" is a little green but nice and warm. The "Natural" is very nice and realistic. An order with some "Cool" versions will arrive in the middle of next week.

The LED Specs are . . .
1w - 3.5v - 350ma - 105 lumins
3w - 3.5v - 700ma - 270 lumins
5w - 6.5v - 700ma - 550 lumins
10w - 10v - 1000ma - 950 lumins
20w - 31v - 700ma - 1700 lumins
30w - 31v - 1000ma - 2750 lumins
50w - 31v - 1700ma - 4750 lumins
100w - 31v - 3500ma - 8500 lumins
They spread light 180 degrees from the face, but they are brighter with better color in the center area, They are rated at a 120 degree angle. The Higher power versions are harder to work with because of the 31 volts need to bring it up to Full Power. About the only way to use them is with a Boost Converter so I have decided not to mess with anything higher than 10 watts that requires 31 volts. It is easier to use multiple 5 or 10 watt LEDs to make the lighting and it's better light because it is spread out more.

The light coming from these things is a point source and it can hard on the eyes, If you look directly at them for more than just a glance, then you will see dots for hours burned into your eyes. Some kind of fixture needs to be used that will spread and soften the light and make it more appealing.

After playing with this batch of LEDs I put in another order for the ones that I liked, plus a few colors including Ultraviolet. Should be here in a few days . . . Can't Wait . . .
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Offline hiker1

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Re: Using High Power LEDs to Make Lights
« Reply #1 on: November 05, 2018, 12:50:05 pm »
Are you thinking of a bike lite with those...?   Thought about rewiring this...super brite..
just do it

Offline WooferHound

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Re: Using High Power LEDs to Make Lights
« Reply #2 on: November 06, 2018, 08:02:19 am »
Here are some more experiments that I made to learn more about these LEDs



The first thing I made is pictured on the Left. I glued two 1w LEDs to a strip of aluminum. One was a Warm White and the other was a Natural White. This was to see what the colors look like and to see how much heat they produce. Powered from a 4 volt Lithium Ion 18650 battery with 2 ohm resisters inline. This got almost too hot too touch and is when I realized that I need some real heatsinks to use these lights.

The item in the center is an emergency light I made with a single LED with a good heatsink. It does not have a switch and powers up when a battery is inserted. It will run for about 5 hours on a 4 volt 18650 battery. I tried this one outside at night to see if this 1w LED would be useful on the Bicycle and was pleasantly surprised at how well it works, it lights up the whole area. The 1w LEDs are 3.5v at 350ma so I would only want to use 1 with the single battery on the bike.

The light on the right-hand side was built yesterday. It's built on top of a 2100mah Lithium Cell Phone battery. It has a single 1w Warm White led glued to a small heatsink, then glued to a big nail. Everything is glued together with 5-minute Epoxy. It has a Slide Switch and a 1/8 inch plug to be used for charging the Cell Battery. Best for emergency lighting but it was more of a fun little project

7883-1

The most useful thing I made was this cute little battery powered Gooseneck Lamp. It has Two 18650 batteries for 8 volt power, and it uses a 3w LED which is 3.5v 700ma. Inside the chassis box is a Buck Converter to regulate the power to the LED so it stays the same brightness and color as the batteries drain. It will last over 6 hours on charged batteries and the 3w LED makes it wonderfully bright. Really nice to use when working close to some small projects and need good lighting.

7885-2

Should get my new LED order in the mail tomorrow. I have already started assembling a couple of things that I will use those LEDs for.
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Offline Pete

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Re: Using High Power LEDs to Make Lights
« Reply #3 on: November 06, 2018, 03:10:01 pm »
Looks like you are having lots of fun Woofer.
I like the cute little light on the aluminium box.
We use 12 volt lights in our house, a mix of LED bulbs and LED dichroic lamps.
The new 12 volt LED bulbs are great, I find a 7 watt LED bulb is great as a reading lamp, general lighting.
Keep on experimenting,
Pete

Offline Wolvenar

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Re: Using High Power LEDs to Make Lights
« Reply #4 on: November 06, 2018, 11:34:44 pm »
I remember buying LED lights ~1 watt  in the early 2ks
At one time I checked they were $40+ I finally got one for a flashlight once they dropped to about $25

That flashlight works flawless to this day. It's been through 3, 6v lead acid batts in its life, but the led is still going strong.
Trying to make power from alternative energy any which way I can.
Just to abuse what I make. (and run this site)

Offline WooferHound

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Re: Using High Power LEDs to Make Lights
« Reply #5 on: November 07, 2018, 07:07:44 am »
For the last week I have been using this little lamp I made to that will light up my computer desk which is also a small workbench a lot of times. It is attached to a lighted magnifier. The wiring is temporary for now but I use this light all the time now.



Basically it's LEDs glued to a CPU Cooler that has been mounted inside of a small 3 inch PVC pipe ring. Two power feeds, one for the LEDs from the buck converter, and another feed from the 12v solar power to the fan through an 82 ohm resister so it is slow and quiet.



There are four 1w LEDs glued into the 4 corners so the light will come from a wide area and soften the shadows that will be created from it. Two LEDs are Warm White and the others are Natural White, wired into a series/parallel arrangement, making it 7 volts at 700ma or 4.9 watts.



I have so much of this LED stuff going on that I have decided to build a box with 4 buck converters in it to power some more lighting that is planned after the Mail runs today with another pile of LEDs to play with.



The picture above was taken using this light and the camera white balance set to Incandescent. You can see  the Soft Shadow effect from the box.
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Offline Pete

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Re: Using High Power LEDs to Make Lights
« Reply #6 on: November 07, 2018, 02:55:16 pm »
Hi Woof, I also have one of those magnifier lamps. I took the flouro tube out of mine and installed LED's. I bought some that were three leds on a strip and they had plugs that allowed them to be paralleled. They came with sticky backs so I just stuck them around the inside of the lamp where the tube was, junked the mains parts and connected it to 12 volts. Works great, probably not as bright as your newer LED lamp though.
Great to see someone having fun
Pete

Offline WooferHound

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Re: Using High Power LEDs to Make Lights
« Reply #7 on: November 07, 2018, 07:47:59 pm »
Well . . . I thought about it too much and decided not to make a box full of Buck Converters, instead I made some individual boxes that are attached directly to the lighting that they control.

The box on the left has 2 buck converters in it which will control 2 lights on the Lighted Magnifier pictured above, including the PVC Tube Light also in the story above. The other light will be on the Back Rail supporting the magnifier and will face up toward the ceiling for some indirect uplighting. There are a couple of Air Holes drilled in the box for cooling but it doesn't really get warm.



The Box on the right has a single Buck Converter in it and powers a couple of white LEDs that light my Computer Keyboard from above. Two normal 20ma LEDs in series so only 20ma total. Then I tried to set the buck converter to 20ma there was an odd flashing effect. Tried several things to fix it and it finally worked OK at 20ma with a 1000mfd capacitor across the output.

I was having trouble with some projects using the Buck Converters around fans where I could see a slight strobing effect, indicating noise and flashing. Was also getting a high frequency tone through my 12 volt sound amplifier. I have found that a 470mfd capacitor across the LED will stop those problems.
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Offline WooferHound

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Re: Using High Power LEDs to Make Lights
« Reply #8 on: November 17, 2018, 05:26:19 am »
I have been working a lot lately and haven't done much with the LED lighting, although I have been experimenting with the High Power Colors that arrived in my last package.


Here is 1w Blue and Red Together. Getting ideas for Nightlights here


This is 1w Royal Blue. A really interesting color between Blue and Ultraviolet


And this is a small circuit board with sixteen 5mm Ultraviolet LEDs soldered to it


I also have several projects started which will provide strong White Light. This is a test of a triple-brightness lighting fixture being constructed to mount to the ceiling over my computer desk/workbench. It has a 5 watt LED for the Low level and four LEDs that total 10 watts for the high level. so it can be switched to 5/10/15 watt levels. It sure is bright and competes with Sunlight coming through the window.

 More to Come . . .
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Offline solarnewbee

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Re: Using High Power LEDs to Make Lights
« Reply #9 on: November 19, 2018, 11:55:38 am »
Hey Woof!

I have installed and repaired many outdoor 100w led floodlights of the Chinese persuasion and they use the case as a heat sink and use thermal paste under the led and screw it down. The led’s are the same like the 20w you show in the pic. I have used a thermal glue to attach waterproof Dallas temp sensors to my inverter and find it works quite well. I just bed the sensor in a glob of it and masking taped it in place for 24 hours. Not as fast as epoxy but I feel like it conducts heat better. Of course the fixtures I installed had a flaw in that the case had minimal fins on the back and the entire surface area was only 10”X10”. This may be why they failed so often or power surges lightning. I did install a a high quality surge protector on the parking lot lighting system and failures have slowed.

I wonder if you were to epoxy a 100w led to a heat sink that it may begin to melt the epoxy? There are scew holes so maybe consider drilling holes. I designed and built a dump load for my windmill and drilled holes in the heat stink, thermal past under the resisters and small screws.

Like your projects. Keep on keeping on bud!

SN
SN

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Offline WooferHound

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Re: Using High Power LEDs to Make Lights
« Reply #10 on: November 21, 2018, 06:46:01 am »
Hey Woof!

I have installed and repaired many outdoor 100w led floodlights of the Chinese persuasion and they use the case as a heat sink and use thermal paste under the led and screw it down. The led’s are the same like the 20w you show in the pic. I have used a thermal glue to attach waterproof Dallas temp sensors to my inverter and find it works quite well. I just bed the sensor in a glob of it and masking taped it in place for 24 hours. Not as fast as epoxy but I feel like it conducts heat better. Of course the fixtures I installed had a flaw in that the case had minimal fins on the back and the entire surface area was only 10”X10”. This may be why they failed so often or power surges lightning. I did install a a high quality surge protector on the parking lot lighting system and failures have slowed.

I wonder if you were to epoxy a 100w led to a heat sink that it may begin to melt the epoxy? There are screw holes so maybe consider drilling holes. I designed and built a dump load for my windmill and drilled holes in the heat sink, thermal paste under the resisters and small screws.

Like your projects. Keep on keeping on bud!

SN

Those 100w LEDs get scary hot. We have some store-bought LED floodlights in our theater that we use as worklights. Last week I looked at them closely and there were only small ripples on the back for a heatsink. I placed my hand on the back and it was burning hot. I don't see how these can last very long working at a temperature that high. Those high power LED modules that hook directly to the 120vac mains, Flash hugely at 120hz, I would use them outdoors but would never work under them. I have seen a lot of YouTube videos about Construction and Teardown of powerful LED fixtures and I always feel that they don't pay enough attention to the heat.

I have given a lot of thought to the possibility of the Epoxy Glue melting, but I have decided to only use LEDs that are only 10 watts or less because they all work well with 12 volt power using Buck Converters to control the current. The heat is very easy to manage using these LEDs and if I need more light I'll just use multiple  pieces until I get what I need. I have tried a 10w LED on a substantial heatsink before and it still got too hot to hold onto but the glue seemed to be OK. I have a small fan that I will add to it later to make it usable.

Here is a small 10w fixture that I made yesterday afternoon. The LED is glued to a CPU cooler. The fan has an 82ohm resister in series to the 12v side of the buck converter to slow it down and keep it quiet. Then it is all glued to a PVC ring to help control the light and will give me a way to mount & aim it later.



I ran it for a coupla hours and the heatsink stays cool to the touch, not warm at all. The backplate on the LED had a hint of warmness, The electrical connections were warm, but the LED case was too hot to touch in a couple of areas. I was very satisfied with the cooling.
These LEDs put out an amazing amount of light using only 10 watts of electricity, 10 volts at 1 amp. I think they were rated at 1150 lumens.


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Offline rossw

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Re: Using High Power LEDs to Make Lights
« Reply #11 on: November 22, 2018, 01:21:45 am »
I wonder how some of these high-power LEDs would go with NO heatsink, stuck between two sheets of glass with a decent circulation of some of these "engineered fluids" they use for immersion cooling of electronic components (read: super high density datacentre computing stacks).

In effect, liquid-cooling and being able to make them very small and quite importantly, silent and cool...

Offline solarnewbee

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Re: Using High Power LEDs to Make Lights
« Reply #12 on: November 22, 2018, 11:18:07 am »
Hi Ross!

How are ya? I’ve seen guys submerging desktop computers in mineral oil and the Fans actually kept all the components quite cool well under oil. The temps were monitored using an app in windows. They did have to add external cooling pump and cooling heat sink as the tank heated up. Then the aquarium started leaking and that was the end of that. Maybe a frame with double pane glass like you say and a cpu cooler system using mineral oil might work. Hmm wonder.

SN
SN

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Offline Pete

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Re: Using High Power LEDs to Make Lights
« Reply #13 on: November 22, 2018, 02:54:50 pm »
I have used 12 volt LED's for years now as home lighting. The main problem I have found is that the capacitors in the converter circuits die. Mostly in the dicroic lamps. It seems that sending all the heat upwards to where the electronics are is not such a great idea.
It also seems that electrolytic capacitors are not always what they used to be. Some of the capacitors I have come across coming out of China are only half the weight of older better known products.
Oil cooling has been used in power transformers for many years, the tubes on the outside of the tanks are there for convection cooling.
keep having fun Woofer
Pete

Offline rossw

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Re: Using High Power LEDs to Make Lights
« Reply #14 on: November 26, 2018, 03:10:19 am »
I’ve seen guys submerging desktop computers in mineral oil and the Fans actually kept all the components quite cool well under oil. The temps were monitored using an app in windows. They did have to add external cooling pump and cooling heat sink as the tank heated up. Then the aquarium started leaking and that was the end of that. Maybe a frame with double pane glass like you say and a cpu cooler system using mineral oil might work. Hmm wonder.

Not oil. Certainly not oil. It does a nice job cooling, but it has more downsides than up.

Google Novec, or Novec 1230. Your components come out of Novec clean and dry.