GUIDE TO LED PROJECTS

184,830

254

107

Introduction: GUIDE TO LED PROJECTS

INTRO.

I had to do this project for many of my young friends who are interested in LED’s but do not know how to go about it.

I also had the same problem but was fortunate enough to get HELP from my friends at www.Instructables.com.

This is not about any calculation or study but a set of proven rules to follow and get results,

which anybody can do if he has the mind to.

Here I have shown you many types of power supply which can be used to glow a LED.

I have also shown here how different types LED's can be made to glow and use it in you project.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: KNOW YOUR LED

A 15 mm LED has two legs, the long one is the Positive and the short one is the Negative.

It consumes 15 milli Ampere of current and can glow on 3 Volts DC Current, or a 3 volt battery.

LED’s are Diodes and the current can only pass through the POSITIVE side.

Always remember to maintain the POLARITY of the LED, that is (plus to plus) and (minus to minus) otherwise it will not work.

LED is a one way street. Now you know how to connect an LED in your circuit.

Step 2: KNOW YOUR LED

If you are interested, here you can see the different parts on an LED.

Step 3: RESESTORS TO BE USED WITH LED's

This set of rules will help to build a Project, follow them.

Here I have shown the Resistors to be used with 6 volts, 9 volts and 12 volts DC.

You can go on adding any numbers of LED's.

Remember that the first line of LED should be in series and  the second line onwards should be in Parallel.

Step 4: USING LED's WITH AC TRANSFORMERS.

LED can be run on AC or DC current.

If you want to run it on DC that is Battery Then you must use Resistors.

If you want to run it on AC then use a Step down AC Transformer. (220VAC to 12 VAC)

Here we will deal with AC Transformer

Now what is the load the AC Transformer will take? For that you will have to measure the output voltage of the AC Transformer with a Multimeter, say it comes to 14volts.

The subject transformer was 14VAC 500mA output without load.

First, we have to be aware that the 14V rating is known as the RMS voltage, and is the effective average power of the sine wave. The maximum voltage, which we will subject our LED’s to, is about 1.4 times higher.

So we should expect a peak voltage of 1.4 x 14v =19.6

So, we will be using 19.6 volt as the basis of our calculations.

We know that most white and blue LED’s range between 3 and 3.6 volts. So by dividing our PEAK voltage by an average LED voltage, we get an idea of the number of LED’s our transformer can support:

19.6 / 3.5 = 5.6, which we round up to 6 LED’s.

But remember, that AC has an identical NEGATIVE cycle! Which means we can add a mirror circuit that work on alternate phases,

that is 6+6. The advantage of using voltages to start our calculations is that, as long as we stay with similar LED’s, and stay within

its operating voltages, the current will stay within safe limits. So, by adjusting the number of LED’s in use, we can handle most AC

transformer outputs. We can multiply the light output up to 15 times just by adding chains of 6+6 LED’s arranged the same way

across the supply! 15 times means 90+90=180 LED’s
.

Step 5: LED's CAN GLOW DIRECT ON 220volts or 120 Volts AC MAINS.

You can use LED’s directly on 220 volt or 110volt AC.

Same principal applies, one line opposite to the other while using AC.

The value of the Condenser and Resistors are given in the diagram for 220 volts and 110 volts.

The condensers must be non-polar.

You can use 30 + 30 LED's on a string, after that if you start adding more LED's the light starts to get dimmer.

Step 6: USING 1 WATT LED’s

Here you can see the various types of 1 watt LED’s.

Their polarity are marked on the legs or body.

They glow on 3 volt and consume 350mA of current,

so you must calculate the power source to be used with this LED.

Step 7: USING 1 WATT LED WITH BATTERY.

Every thing is explained in this Diagram.

Step 8: RESISRORS TO BE USED WITH 1 WATT LED.

You can use different types voltage and resistors with this LED as shown in the Diagram.

Step 9: USING STRIP LED IN YOUR PROJECTS

Everything is clearly explained in the Diagram and it is very easy to use strip LED's.

Now you can make your own LED projects.

Participated in the
Epilog Challenge V

139 9.6K
81 7.4K
195 12K

107 Discussions

I want to cunnect 4v led through 12v battery how?

In the picture where you have connected a 1W led to a mobile phone battery, won't the LED burn out since there is no resistor to limit current causing the LED to draw the full 700mA current and thereby destroying itself?

Hello all! im looking to put some small Leds on a new guitar fret board on the side to see side dots lit up for playing at night. Can anyone help me with a circuit that would run off a 9 volt battery when guitar jack is plugged into the guitar lights come on! I know I will need 10 micro lights but have to be really good quality. That's all I know I may try a 20 light on next project. Thanks so much.

Value of this led register

Can you please let me know what resistor I will use with this led to glow with a 4 v battery???

Can you please let me know what resistor I use if I want to glow this led with a 4 v battery???

what power supply can I use with a 2m leds strip 5v what is the amp requied and can I use batteries 3 nmh rechargeable. These are addressable RGB Leds ?

If I want to run 6 led of 1 watt with 5 volt supply can my led glow up?

Hi I am building a model airport runway, And will be using 550 led diode 3 and 5 mm. Of various colours. What I like to know is how many led diode can I connect to a 12v DC Transformer ?. I am using resistors on each diode. Thanks for your help regards.

Hi Do anyone have a answer for this question? Thank you.

Whomever produced that first image of the LED diagram must have taken art lessons from Escher... Pretty cool.

sir can you help with this please 220 colour changing leds wired in parrallel what power supply to use

I have an 1w x 7 light. I,m set this lights serios system. Then can i connect a 12v ups battery without any cercuit? Sir, please exlain me.

Hi Sir, I got a led project that I assume is similar to your "step 4" the ac transformer.

I have a power supply that step down to 9VAC and 200ma. I am using the 1 watt LED, which is exactly the one you have on your step 7.

My question is: I assume I can put minimum 8? : 4 in series ( 9 x 1.4= 12.6v) and 4 more on the negative cycle.

My second question is: What is the max number I can put them? I assume is 15 x 8, so 120?

Thank you for your time and the help

i might not be your good sir ,but i know i can learn,witch is that what you have there is ether a rectified transformer or a smps (switch mode power supply) witch are both dc not ac in outer words half of your led's wont light up

to make it easier to understand just treat that transformer as a battery follow step 8 and you should be good

Sir can you tell me the ampere rating of the step down transformer required to glow a single 1 watt LED light from a 220v source?

Hello I want to connect 20 1W LED. which one should I use power supply?

My Prof recommend me to use 3V-20W but I cannot find it. what is another option to do it? I can divide 10/10 so 2 groups. this project is killing me.

Use this circuit it is easy and reliable...

Hello, i have a question about connecting 1W, 350mA leds to a power bank.
I was wondering if i could connect 7 1W, 350mA 3.2-3.6V Leds to this powerbank,
http://files.xiaomi-mi.com/files/power_bank_20000/...
and what would be the best way to do it?
I think i should connect them parallel, and add resistor, but i dont know which DC output i need to consider for this? It says it is 5.1V, 2.1A(3.6A max), but battery is 3.6V.
7x350 is 2,450, but if i connect them either way, each led will get 300mA and should work just fine but dimmer?
But i need help with figuring out the voltage, and what resistor if any to use.