Today I will show you a method to build a USB LED light for your laptop if yours don’t have.
This is not a new invention or development. It is an article for those who don’t want to buy the product and save some money. The parts we will be using to build our USB LED Light would be available at your home, somewhere lying in the corner for no use. Let’s use these materials and make them useful.
- USB Wire Cable ( Data Cable )
- Wire coating ( Not necessary )
How to take Power from USB Cable
Well, the main question arises, how are we going to take power from USB data cable. The USB data cable has four wires, two are for Power - Ground, other two are for the transfer of your data.
This is evident from the fact that your data cable is used for both chargings as well as transferring the data which includes copying, deleting or moving. We will use those two power and ground wires for our LED and leave the other two. Hence our LED will be able to glow.
The next question that arises is why do we need to use the resistor? Resistor is used because voltage requirement for LED is 2V but the USB port supplies 5V. So in order to have 2V accurately we use a resistor in series to the LED so that there occurs the voltage drop across the resistor.
Calculating Value of Resistance for LED
Total Voltage Supplied: 5 Volts.
Voltage across LED: 2 Volts. If you take LED of other Voltage ratings then change it.
Voltage drop across Resistance: 3 V.
Current Reqd: 20 mA (milliampere).
R = 3 / ( 20 * 10 ^ -3 )
R = 150 Ω (ohms)
How to identify the positive and negative ends of the LED
The LEDs are biased devices means they only work if the current flows through them in one direction. Therefore it is necessary to identify the pins of the LED for making it work.
There are various methods to identify the Pins of the LED and most commonly includes identifying by observing or by the multimeter.
You will see that the two legs of the LED are not symmetrical, one leg is longer than the other one. The longer leg is the anode and shorter one is the cathode.
The Current from the LED flows from Anode to Cathode.
How to do it?
Take any old data cable lying in your home of no use, if you buy a new one then this project is going to be of no use as there is product available for USB LED light that is available at a slightly higher price than the cost of USB Cable. So take the old one.
Cut the Data Cable from the side of USB Port, There would be four wires. Two for power transmission and the other two for data transmission as I have explained before.
Connect the resistor to the 5V line of the USB cable with the positive end of the LED. You have to keep in mind these things, if you do it wrong then you going to short the circuit. To take precautions read how to identify the 5 V line of USB Cable.
Now connect the negative end of the LED to the ground of the USB cable, for making the connection complete.
Now your connections are complete. The next ерштп you need to do is coating your wires. To make it flexible you may use the сoating of other wires in your home like the coating of the wire of iron, washing machine or any other electrical device.
The last thing you need to do is provide the cap for your LED. Or may not provide, it also will be fine.
Hence your USB LED light is ready to use. Now you may plug it into your USB port. Your USB LED light is ready to USE.