Sound detector for photography.

This small electronic circuit is a plugin for the lightning detector.
It is simply composed of an electret microphone and a resistor of 10 Kohms.
The principle of this plug-in is to detect sound which is transmitted to Lightning Detector.
The lightning detector triggers the relay when the noise exceeds the threshold
by the two potentiometers for adjusting the sensitivity.
The relay permit to control the DSLR camera with the remote control from the camera.
For more details on the lightning detector and its implementation,
please refer to the "Lightning Detector" in the "Tips and Tricks" section of this website.

The electronic assembly is visible on photo01 is visible on photo01.
To achieve sound detector will require a electret microphone, a resistance of 10 Khoms and
a box or tube. I chose an old tube of glue stick (photo02), I drilled
one side and pasted the electret microphone to make a directional microphone (photo03) to remove
parasite noise.
Photo04, you can see the microphone in the tube connected to the lightning detector by the black wire.
The microphone, and the lightning detector, are connected to the same 12 volt transformer
with an adapter like Jack.

The detection of a sound takes a few milliseconds.
Each digital DSLR camera at a time trigger different, for my Nikon D90 the
time is approximately 100 ms.
Thus the detection of the bursting of a balloon or exit of a bullet from the barrel of a gun
is not possible with my Nikon D90 because the trip time of the photo is of the order
100 ms.
So I have, for testing the sound detection,and for give you some examples, taken
Photos from the lighting of a lighter.
The different pictures (from the photo06 at the photo10), you can see the sparks
caused by the ignition of the stone and the early life of flame.




Copyright 2010 ThierryD - http://rienquepourlesyeux.free.fr
Last update 20/10/2010
Reproduction prohibited