Hi dear friends I would like to work on a project whose title is design and implementation of a Microcontroller-based relays. So, Any Idea How to Start? At the begining I will use Hi_level language 'Matlab" in order to simulate the algorithm. A method called " Four-Sample Method" should be used to identify the signal “basically taking one sample each ¼ of the period (T=1/f=1/60) and using these samples to calculate the RMS value of the current to be monitored”. After getting the RMS value, it is to use another algorithm to implement the relaying decision part of the program. It is required to see the current value continuously in the normal condition and then if fault occurs. We are working on it as a group but no matter to share the ideas here.