Description
This circuit is used to trigger a camera’s electronic shutter circuit when a flash of lightning is present. This circuit would also work for photographing fireworks displays or other events involving flashes of light.
Theory
In a nutshell, the photo darlington converts light pulses into electrical pulses, the first LM324 section amplifies the electrical pulses, the second LM324 section is a high pass filter that only passes quick changes (lightning). The third LM324 stage is a comparator that allows only large pulses to pass through, and the 4047 one-shot stretches out the length of the pulses so that they are long enough to drive the relay and trigger the camera.
The 2N3904 drives the reed relay, which in turn triggers the camera’s electronic shutter switch. The VN10KM prevents the circuit from triggering the camera when it is first turned on. The LM324 GND Ref circuit divides the 9V power into two for a 4.5V ground reference. The other op-amp circuits use this reference value.
Related Links
More Circuit about LM324
More circuit Lighting Senser
More circuit Light Switch
More circuit about Lighting
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Light Detector by IC CD4001
Dark Activated Switch by IC 741
Light Sensitive Switch with LDR + 2N2926
Read More Source :
http://www.solorb.com/elect/lightning/
This entry was posted on Saturday, August 4th, 2007 at 12:22 pm and is filed under Electronic Control, Lighting, op-amp circuit.
