Technology enthusiast and instructables member zmashiah has created a nifty project that can help save energy and equipment wear and tear. By monitoring the audio feed going to an amplifier, an Arduino can then turn the power off when the amp hasn't received a signal for a set period of time - in effect, making an automatic shut down. Furthermore - when the amp is off and a source starts playing, the Arduino can turn the amp back on. Finally no mains current wiring is required as the control is via infra-red.
Thinking of embedding an Arduino-compatible board in your next project? Consider using the Freetronics LeoStick:
Apart from being one of the smallest Arduino-compatibles on the market with USB, it also has an onboard RGB LED and piezo which can be used a knock sensor and various tune and sound effects. Plus you can add extra circuitry with the matching protostick! For more information and to order, click here.