How to Light LED using Mains

This post is about how to light up a LED using mains supply.

Disclaimer: This post is regarding the use of mains power supply. This tutorial is provided to just give the theoretical introduction to how to use an LED on power supply. This tutorial is to be performed only by an experienced person who has good knowledge about electronics . I am not responsible for any harm to you. If performed carelessly it may lead to fatal electric shock.

All around the internet you may find a lot of ways to light up an LED most of them showing the use of zener diode, capacitors, a number of resistors to just light up an LED. 

Although these are safe but they are very complicated especially if we just want an indicator for any device. This design is very simple the knowledge which you need to have is all about ohm's law and the resistors.

The Ohm's Law states that resistance is equal to voltage divided by amount of current passing. This can also be derived from this expression that we can find the voltage and the current with a simple resistance.

For general use with LEDs you can use a resistor with a resistance of 100 K Ohm 1/4 W 

This produces a current of 0.022 amps or 22 milliamperes. Usually an LED requires a current of 20 milliamperes. If you want to add a number of LEDs you can put them in parallel but be careful noot to put up a lot of load on a single resistor or it will burn out or will become very hot, thus to avoid it you may add the number of resistors required for every series .  

Note: An effort is made to provide correct information but the editor is in no way responsible for any error in this article.