Relay activated with Sound

This is a Relay activated by Sound Circuit Diagram. Generally a circuit has a basic function, but according to our needs can modify or add to a circuit making it more complex. This circuit is a relay activated by sound, which can be used in an alarm system, home automation, robot and even in an Arduino. Undoubtedly this control by sound can be very useful, an example is a light activated by the sound of a knock on the door or a round of applause.

Relay activated with Sound Circuit Diagram:

 
The light turns off automatically after a few seconds. An alternative is to use protection against theft - if someone wants to open the door or break something light illuminates, indicating that someone is home. The circuit can work with any voltage 5-12 Vdc, it depends on the voltage of the relay coil.