DIY LED lighting

[_BaDgUy_]

Over the next few days, quite probably weeks, I'll be posting a DIY guide to LED lighting.

This first post will guide you through what you want to accomplish with this lighting.

Remember, LEDs are electronic "lights" which give off an extremely specific visible, sometimes invisible as in IR LEDs, wavelenght, or color. They will not give off a full spectrum of light as in fluorescent lighting, or any other type.

Do you want a white lighting for general tank use? White LEDs might not be very beneficial for plants or algae according to the color emited. I'm testing out a few "modules" to see what it will do to plants. I'm hoping it might help a bit with them. What I'm hoping the most is that it will not cause an algae bloom!

Plant lighting? We all know that photosynthesis occurs in the blue and red portion of the light spectrum. There are blue and red LEDs out there that come pretty close to the exact peak of the photosynthesis curves. I'll be doing some tests with these later on in 2009, I'm still waiting on my blue LEDs.

Night lighting? Some try to duplicate the effect of the moon through blue lighting. Might be beneficial to some fish for reproduction. Also helps in observation of your fish at night!

Decorative lighting? Special colors might be wnated to get some part of the tank to stand out!

There are thousands of models of LEDs out there. 3mm, 5mm, 8mm, 10mm, square, round, triangle, tall, short, flat top, dome, single color, 2 or 3 color, flashing, norrow beam, wide angle beam, and in pretty much all colors of the rainbow from the UV range all the way to the infrared range!

In the next post of this DIY, I'll explain the basics of LEDs, including voltage, current, color, visible wavelenght.

[jujube]

Thank-you!!!
This is so cool. My husband is building my aquarium stand and we were thinking about a DIY LED system. The ones on the market are sooo expensive. My tank is 72 x 24 x 30 inches or 182.88 x 60.96 x 76.2.

[_BaDgUy_]

Second chapter coming up this week!
The holidays have been hectic, so no time to write up anything.

I'll be spending the weeking driving around on a fork lift at work, so I'll have plenty of time to think of everything to write up more stuff!

[_BaDgUy_]

Here goes for chapter #2 on LEDs!

Here are the basics. As with many electronic components, there are specifications and limits to LEDs. If the specs and limits are not respected, your LEDs will have a much shorter lifespan than indicated, and that lifespan could be as short as 1 second!

Since LEDs run on DC (direct current), they have a positive side and negative side.
99% of the time, the part of the LED that seems to have a "chip" missing, and/or has a shorter lead, is the negative side.

Here is a picture of common LEDs
http://img.photobucket.com/albums/v314/dwarfcichlids/LED.png

Here is a picture of the LEDs I commonly use. Notice the top left corner has a 45 degree cut to it. That's the negative side indication.
http://img.photobucket.com/albums/v314/dwarfcichlids/superflux.jpg

The positive side of your power supply will be connected to the positive side of the LED. I'll elaborate more on this later!
If the LED is connected the wrong way, reversed polarity, 2 things might happen.
1 - if the supply voltage is low enough, nothing will happen.
2 - if it's high enough, instant short term powerfull light, and then nothing (the LED is now useless!)

[_BaDgUy_]

I decided to cut down on the length of the messages to make it easier to follow!

Here goes for the specification part of LEDs!

There are many specs for LEDs. Every single one of them is important is designing a DIY LED lighting, no matter what it will be used for.

Here are the common terms and abbreviations for thoses specs, and what they mean.

Power Dissipation (PD) = the power that the LED can handle before burning up (in mW (milli watts).
(this is not the light power given off by the LED)
Forwar Current (IF) = the average current the LED can handle (in mA (milli amperes)).
Peak Forward Current (IFP) = the maximum current the LED can handle (in mA)
Reverse Voltage (VR) = the maximum voltage the LED can handle if the polarity is reversed (not hooked up the right way) (in volts)
Operation Temperature (Topr) = the common temperature the LED will function correctly (in degrees C)
Forward Dissipation (VF) = sometimes reffered to as forward voltage. This is the working voltages for LEDs (in volts)
Reverse Current (IR) = the reverse current the LED can handle when the polarity is reversed. (in uA (micro amperes))
Dominant wavelength = the dominant wavelength emited by the LED at the average current recommended (in nm (nano meters))
Luminous intensity (IV) = the amount of light given off by the LED at the recommended specs for IF and VF (in mcd (milli candelas))
50% power angle = the width of the light beam at 50% of it's useful lighting range (in degrees)


Next installement : what all those numbers in the specs mean for our use!!!

[_BaDgUy_]

Here is the next installment!!
What do all these numbers really mean in the real world?!?!

I'll use some specs from LEDs I found on eBay.

Emitted Color Green
Size (mm) 5mm
Lens Color Water Clear
Peak Wave Length (nm) 520 - 525
Forward Voltage (V) 3.0 - 3.3
View Angle 5 - 25°
Luminous Intensity (mcd) 12000 - 15000
Maximum Current 20mA Continuous, 50mA peak for 10% Pulse Width


Those are some typical specs given on LEDs. More info are available from other sources, but these are the basics.

Emitted color : well, it's the color you will see once the LED is lit up!

Lens color : water clear means the lens is just that, water clear. You'll have diffused, which is frosted, and color diffused, which is frosted, but with color to match the output of the LED.

Luminous intensity : 12,000-15,000 mcd. That's the brightness of the LED. the higher it is, the brighter it will be. The intensity is specific to LEDs, and cannot really be transformed into watts of light, or any other format.

Viewing angle : the light given off by the LED will cover 5-25 degrees, which is a narrow angle for LEDs. Superflux (or piranha) LEDs (square LEDs with 4 leads) have a very wide viewing angle. Regular LEDs have a very narrow viewing angle (usually around 15 degrees). The wider viewing angle, the better the results will be in an aquarium, unless you want to emphasize a specific point in the aquarium.

Peak wavelength : that's the actual color wavelength given off by the LED. It is measured the same way other lighting is measured. The wavelength given is the dominant wavelength, and does not vary much within a specific batch of LEDs. In this case, a wavelength of 520-525nm is given. By experience and research, the dominant wavelength should be anywhere between 515 and 530 for this LED, which is quite close to the 520-525nm given.

Here is a chart of colors by wavelength.
http://img.photobucket.com/albums/v314/dwarfcichlids/wavelength.png

Forward voltage : 3.0-3.3v This LED will work at voltages between 3 and 3.4 volts. It was designed to work in this range. It will probably work at higher or lower voltages, but the lifespan will be shorter than expected.

Typical voltage : (not given here) is in the middle of the forward voltage, 3.15 volts This LED was designed to work at it's most effecient at 3.15 volts. Most of the specs given were measured at this voltage.

Typical current : 20 mA This LED was designed to work at it's most effecient at 20mA. Most of the specs given were measured at this current. The LED will work at lower currents without any problems. Higher currents will work, but with special electronic circuits, so it should not be attempted!

So, to resume, the green Led works at a typical 3.15 volts, 20 mA, and at that voltage and current, will give off a color of 520-525nm and a luminous intensity of 12,000-15,000mcd.

LEDs work in a linear way, meaning that the more current that goes in, the luminous intensity will be higher in the same manner. A 10% increase in current will give off 10% more light. The same thing happens at lower currents : 20% less current = 20% less light.

A side note on white LED color.
Since these are rather hard to measure, the color, or peak wavelength is usually not given. Pink LEDs also have this problem.
Some people have a way to measure them, but in another way. They are measured on an x/y color axis, and the results are given in the same fashion!
Here is an example of the peak wavelength given for some white LEDs: x=0.28, y=0.31

They have to be place on the following chart to have an idea of what white "color" hue this will give. In this case, the white LED will give off white light, but in the green range of the spectrum.

http://img.photobucket.com/albums/v314/dwarfcichlids/Dominant_wavelength.png

Hope this helps out a bit!

Next time comes the really fun stuff : actually designing the LED lighting system!!

[_BaDgUy_]

Here goes for what is needed to build your own LED lighting for your tanks!

Tools :
Long nose pliers
Cutters
Utility knife
Soldering iron
Wire solder

Material:
DC Power supply
LEDs
Resistors
Wire
PC board
Hot glue gun with glue or silicone
Voltage regulator (optional)

For supplying power, you will need a DC power supply. You absolutely need one that will give enough voltage and current for your project. With the LEDs you will need, you can calculate exactly what you need as a power supply. All LEDs work in a direct current fashion (DC). Do not try to make them work with an AC supply, the LEDs will burn up very fast (read instantly)!! More on that further down.

For LEDs, you can use whatever you want. Just keep all those specs that are given handy, because you will need them to calculate a few things!

Resistors will help control current and voltage that makes it to the LED. Calculations on these further down!

A PC board will be required for mounting all the parts together, and installing it on your tank.

You will need either a hot glue gun or silicone to make the system "water proof". Evaporation from your tank will corrode all the metal parts in the system, which can lead to failure.

A voltage regulator is not necessary, but it can help with power supplies that give off too much voltage. Once Again, more on this later!

[_BaDgUy_]

Now it's time for all those calculations. Whip out the calculator, paper and pencil, and those specs for the LEDs you have/need/want!

I'll use some specs for some blue LEDs I got recently.

Color : Blue
Type : Piranha (superflux)
Viewing Angle : 90 degrees
Forward Voltage : 3.0-3.1 volts
Forward Current : 20ma typical
Luminous intensity : 1200-1700mcd
Wavelenght : 465-467nm

For all your calculations, you will only need the forward voltage (3.0-3.1 volts) and the forward current (20ma).
On average, the voltage and current are all the same for LEDS, but there are 2 variations.

Forward current will always be 20ma. There are LEDs that may be designed as triple chip or 5 chips. What this means is that there are 3 or 5 LED assemblies in a same housing. Each assembly will need 20ma, for a total of 60 or 100ma.

Voltage depends on color.
IR LEDs need 1.5 volts for operation.
Red, yellow and orange LEDs typically need 2 volts for operation
Blue, green, white, pink, purple, UV LEDs need 3.3 volts for operation.

So, I'll be using my blue LEDs at 3.1 volts, and 20ma.

I plan on using 20 blue LEDs in my tank.

20 LEDs x 20ma = 400ma

I'll need a power supply that can give me at the very least 3.1 volts, and 400 ma of current.

To be on the safe side, I would choose something that can give me 4 volts, and 500ma, or 0.5 amps. For something this small, a simple DC adapter that plugs in the wall should be sufficient, as in a cell phone charger type of adapter.
Any DIY LED project that needs something bigger than 1000ma, or 1 amp of current, you should invest in a good power supply designed for LEDs, or a universal DC power supply for testing purposes.
I'll post a picture of my power supply later today. It's a big 20 amp 12 volt power supply for testing car radios, amps, CBs, amateur radios, and other of the sort.
As for power supplies designed for LEDs, I don't know if I can post a link for these, so maybe Melody or Jay can tell me if I can. Otherwise, internet is your friend for these!!

So now, I have my LEDs at 3.1 volts, 20ma, and my 4v 500ma power supply!
You can wire your LEDs directly to the power supply, but they will last only a few minutes at the best.

You now need resistors so you can have the approximate 100,000 hour lifespan of the LEDs!

You can type in LED calculator in your favorite search engine, and use what is given there!
Or you can use this simple calculation :
Resistor = (supply voltage - forward voltage)/forward current (or desired current)

In my case : Resistor = (4v - 3.1v)/20mA
= 0.9v/20mA
= 0.9v/0.020A
= 45
You have to convert the mA to A (milli Amps to Amps). There are 1000ma in 1A :yes:
The result given is 45. Resistors are measured in ohms. So each LED will need a resistor of 45ohms for it to work properly, and last a long time.

You can do this with any power supply or current you want!

If you use a 12v power supply, and want only 12mA on your blue LED, you will need a resistor of 742ohms. Your power supply will have to give off only 240mA for my 20 LEDs.

Now, for resistors, there are different types! The most common are carbon film resistors in 1/8, 1/4, 1/2 and 1 watt versions. Use the 1/4 watt version. They will last longer, and are very low priced. 100 resistors should be around 2-3$.
Resistors do not come in all values from 1 to 1 billion ohms! That would be way too expensive to fabricate. You will have to choose the closes value to what you need.

For 45ohms esistors, the closest value is 47ohms.
For 742ohms,the closest value is 750ohms.
Always use the value above what you need.
The higher the resistor value, the lower the current, and vice versa.
If you choose a lower value, your LED will have more current going through, therefore lowering it's lifespan!

Here is a useful note on LEDs and resistors.
LEDs do not generate any heat if they are in their proper operation range.
Resistors WILL generate heat!
The further away you are from the LED's forward voltage with the power supply, the more voltage the resistor will have to regulate, therefore generating heat, and a possible resistor burning up.

The voltage regulator mentionned before will do just that, regulate voltage. I use these between my power supply and LED/resistors to keep the voltage down on the resistors, so no need to worry about the burning up. Instead of the resistor generating heat, I have the voltage regulator generating heat! It comes out to about the same, but the regulator is more stable than resistors for the voltage drop needed, and is designed for more heat.
If people want more details on these, just ask, I'll write up a seperate post on these for LED purposes.

The last part you need is PC (printed circuit)boards. They ard fiberglass boards with holes and solder pads on them so you can solder LEDs, resistors, and wires together.
A quick search on the internet or eBay should do the trick for these. Just find the dimensions you need!

Next installment : actually building the board with all these parts. How to connect all the wires, resistors and LEDs together. Hope you don't have a 56k internet connection, I'll have lots of pics up for this. Also, basic soldering knowledge will be required for building this!!

[_BaDgUy_]

This is the power supply I am using.
It's about the size of a small car battery, and weighs about 20 pounds!
It's overkill for what I'm doing, but it's the only thing I had around!!
No need for one of these for LED lighting, unless you plan on having about 850 LEDs burning your fish's eyes (and yours!)

http://img.photobucket.com/albums/v314/dwarfcichlids/100_2149.jpg

[pterfloth]

Reading your thread with great interest. I would like to build an energy efficient canopy to replace my current 2x250w MH and 6 x T5 reef tank setup. Any idea how many LED's this might take?

To experiment, I'll probably start by building a canopy for my 20 gal Seahorse tank.

Keep your info coming! I have read many articles on-line and you are doing a great job explaining things!

Much appreciated!