Lightning Activated Camera Shutter Trigger

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. In a nutshell, the photo darlington converts light pulses into electrical pulses, the first LM324 section amplifies the electrical
Lightning Activated Camera Shutter Trigger - schematic

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. The original photodarlington transistor I used was a QT semiconductor model QT-L14R1. A similar part that is available from Digi-key is the Optek OP560C, part number 365-1073-ND. The VN10KM is an N channel mosfet transistor. If a VN10KM FET cannot be found, substitute a more common IRF520 or similar N-channel power MOSFET. The 4047 is a standard 4000 series CMOS one-shot, Digi-key sells it as part number CD4047BCN-ND. The circuit can be built on a small piece of perforated circuit board using a point-to-point wiring technique. The circuit board can be mounted inside of a small plastic case, preferably made of black plastic. The photodarlington transistor can be mounted in a hole on the side of the box, a small metal clip can be used to slide over the camera`s viewfinder. Unfortunatly, there is no...

Leave Comment

characters left:

New Circuits