Hello friends! I'm Ostin,I ll demonstrate how to control a AC light with Arduino using relay module.It is a simple project and also very dangerous as we are going to deal with high voltage 220v . Do not attempt if you are a amateur in dealing with high voltage.
I'll answer few basic questions, which hits when you are novice!
Why to use relay for controlling AC light?
AC is alternating current 220v (india) which powers the ac lights. Arduino cannot control high volt n amp, but a relay can do this job, which is the sole design of it. so we are using relay as switch to control high power devices.
What is NO NC and COM in relay?
C = Common Connection
NC = Normally Closed Connection
NO = Normally Open Connection
I have explained NO NC COM elaborately in step 3, refer it -if you feel it bit confusing.
I'm going to use NO Normally Open Connection.