I am working with a kit circuit that I ordered online. The circuit triggers a relay when it "hears" a loud noise. I am going to hook the relay to a strobe to capture the moment of impact. with my camera. The circuit by design triggers and "holds" the signal until it hears it again. This will cause my strobe to fire repeatedly until it is tripped again. Is there such thing as a relay or transistor that will fire momentarily when it gets a signal? Do I just need to get a trigger circuit?