Nervous LEDMAN

The nervous LEDMAN is a small
analog interactive light object that responds to sounds and vibrations by flashing a LED.
It's very sensitive, and reacts on human voice over a distance of 3m or more, when put on the right surface, e.g. a wooden table, box or anything that vibrates.

Nervous LEDMAN consists of 3 parts : ( top down )

1)  battery holder & power switch
I use a LilyPad coin battery holder or compatible and a rechargable LIR2032 battery

2) LEDMAN PCB
It's a redesign of a circuit by Yair Reshef .
The original design uses an obsolete opamp and needs 2 batteries for 6V supply.  Now it runs with a single cell and uses a cheap standard opamp + 3 resistors + 1 ceramic capacitor in "beginner friendly" sized SMD packages (1206)

3) piezo disc sensor
this is a common 35mm diameter Piezo sounder/buzzer/speaker/drum sensor. Smaller discs are not recommended until you put LEDMAN straight on a loudspeaker box ;-)

the picture shows an "elektro kitsch" version with vintage power resistors as legs and arms. A flexible 38mm, 3V LED filament is used as LED.

construction notes :
resistor "arms" can be 0...10 Ohm, any wattage.
resistor "legs" can be 0...100 Ohm, any wattage.
LilyPad connection is a bit tricky : the red "+" wire is soldered straight to a LilyPad "+" pin. The black "-" wire tunnels the other LilyPad "+" pin without connection ( it must be isolated) and is soldered to LilyPad "-" pin on the rear side.
The reason is: if you solder a wire to one of LilyPads "-" pins on the battery side, the battery can't be removed anymore !

documentation : 

schematics