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Debris Detector

I have not posted for a while because I am having trouble with my set-up. back in the good old days of pellet work, I'd have trouble and I could figure it out quickly because loading and firing a pellet rifle takes about thirty seconds.


Nowadays, setting up a shot takes a lot longer and it took me quite a few hours to figure out I had a problem.


I am still not sure what's going wrong, but the symptom is that the flash fires the instant the firecracker goes off, not when the debris hits my detector.


So to help figure out whats going on I built up another IR debris detector. Shown here before it gets covered in goo.


The IR LED is hidden on the left arm, the SD5600 detector is on the right arm. All parts are covered with Lexan shields that I have to replace every few months because they get all pitted.


Both the SD5600 and the LED run on 9 volts. the LED is running a current of 100mA and the SD5600 is I don't remember.


These two arm are press fit mounted to a post that I can move further or closer to the target and the two arms are press fit into the tee so I can swing them up and down.


Basically I can put the invisible IR beam as close as I want to the target and the explosion causes debris to cross the beam, making the output of the SD5600 go from 9 volts to zero, which then triggers the flash.


I believe that I measured the delay and it's about 20 usec.


Enough technical gargoyle-isms.



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Taken on August 1, 2012