TV-B_Gone is another fun DIY microcontroller project. It’s a simple remote control for TV that has function only Turn Off. So, there is only one button, power button. No Longer dumb advertisemsent on your TV, just use this cool microcontroller project to switch it off.
You can get this device on the market. But if you want to build it by yourself there are good news for you. Lady Ada an Mitch has build an open source version of the TV-B-Gone. it means you can download the schematic and the layout based on open source license.
How does it work?
If you hit the button it plays simply every shut down code stored in microcontroller and send it out to IR led. The transistors are used to drive a stronger current through the IR-LEDs. The latest TV-B-Gone kit have a range of about 50 meters. For the power supply you can use two battery AA.
picture from : http://tinkerlog.com