[Arduino-newbie] Access 250V light switch

Hi Arduino community,

I’m currently working on one of my first projects. I basically want to build a “clap switch” for my bedroom light. I already figured out how to make use of the sensor, but now I’m facing the problem, that I can’t attach a 250V cable to my board without frying it. Furthermore I don’t even know how to get a non-physical power switch so i can programm an “on” and “off”.
So most of you will probably laugh but I really dont know how to do this. :sweat_smile:
I tried to google it, but I didn’t find any useful results.

Thank you for taking your time, and sorry for the bad english :wink:

A [u]relay[/u] is an electrically isolated, electrically controlled switch.

Most relay coils cannot be directly driven by an Arduino output, and will require a driver circuit similar to [u]this[/u]. And, most relay coils are going to require 12V (or more).

You can find relay boards with the relay driver built-in, or there are lots of solid state relays that can be driven directly from the Arduino.

Someone has recommended power tail switch, which is ideal for switching a lamp without messy wires or exposed 120V leads:


You may have to get the 240V kit and assemble one. Now, if you figured out the clap sensor, make it turn your LED on pin 13 on and off. If that works, connect pin 13 to the power switch tail. You plug it into the outlet and your lamp into it. Then connect the arduino 0V, 5V,and pin 13 to it.