I urgently need to build a simple 120v to 5v power supply for a project. Can somebody please help me how to start i know how voltage regulator work however this is a high voltage drop.
I need it for a project urgently

THANK YOU SO MUCH

 

Almost all modern cell phone chargers in the USA are 120vAC to 5vDC transformers and regulators.

You do not mention AC or DC.

If AC, you will have to use a transformer to drop the voltage to a safe and easier to handle level.

Look at your cell phone charger, ask friends for chargers they no longer use. It is easier and safer than building your own.

 

I agree with Retched. But what will you be using a 5 volt supply for? Some of the wall warts like Retched mentioned might say that the output is 5vdc and in reality it is a different value. I had one the other day that was supposed to be 5vdc and I measured 7.3vdc with my fluke. So if your requirements are of a more precise nature, you might want to take a look at that.

 

mbxs3, most cellphone charger wall-warts are regulated. That is one point I wanted to stress.

You are correct at mentioning about most wall-warts being un-regulated.

Any charger with a USB connector should be 5vDC REGULATED, and they should be a dime a dozen.