[Switching a 240v supply safely .. need advice/help?]

Hi everyone,

I fancy messing around with some  led lights microcontroller stuff and I've always fancied being able to build a system where I can switch plug sockets on/off.  I was thinking of using an Atmega to accomplish this.  I believe I would have to use some relays to switch on/off a 240v AC source?  

Can anyone point me in the right direction to information which could help me with this?  If this was about switching a 5v DC source I'd quite happily get my teeth right in there but with this working with 240v I would be happier knowing I'm doing this safely.  Any hints/tips/advice you can give will be greatly appreciated. :)

Thanks in advance.

KG

nice thread sir... that's is the one that I want to ask....
good job your thread sir ;)

[Adding led brake lights]

I need to build a circuit to detect when the brake lights are on and the turn signals on.  The brake light and tail light are the same bulb.  The tail led light uses 2.4 volts then when the brake is applied the voltage increases to 13.8 volts.  This circuit seems to work on my test board.  When the input is 2.4vdc the leds are on at about half the brightness and when the brake would be applied and the input is 13.8 volts the leds are on full.  The input only has two values: 2.4vdc and 13.8vdc.  These components are just what I had lying around and I think I would use a different op amp in the final circuit because I will need to monitor 4 different lights, (2 brake and 2 turn signals)  The turn signal circuit differs by reversing the 10k and the 100k resistors.  The turn signals input is either 0v or 13.8 vdc.
I read out here that the 741 isn't good to use in automotive applications, idk.  I'm open to better components or design but I can't draw too much current from the light circuit because it is monitored in some fashion by the onboard computer.  Any help would be appreciated Thanks.

that's so cool.. sir..
I wonder how can i easily troubleshoot the defected of that??