Audio Controlled MOSFET


This circuit allows sound to control power to some device (similar to the "clapper").  A microphone acts as an input device and a MOSFET and LED are the output.  Though many implementations are possible, the circuit I created waits for the sound level to pass a certain threshold and then flashes the LED and cycles the MOSFET for about a second.  I attached a Solenoid to the MOSFET and an external power supply just for the hell of it.


Without question, the most time consuming aspect of this project was the creation of a double layer board using the shop tools.  I tried two techniques: (1) bottom (solder) layer cut into FR2 on the modela and the top (component) layer cut using the vinyl cutter and (2) a purely vinyl layer cut board.  Both have their strengths and weaknesses. 


Here is the Schematic showing the MOSFET in the lower right. The external power supply connects on the right side.


The blue is the bottom layer and the red the top.  Purple lines indicate both layers overlapping.