I don't have the complete diagram ready for posting yet, but i am trying to figure out a way to trigger a succession of coils on an *ahem* coil gun using Forrest Mims' beam break detector circuit. As the projectile broke the beam, a missing pulse would register on one half of a 556, that would trip the second half for an adjustable duration, the second 555 would pulse an igbt (or scr?) that would empty the capacitor bank through the coil. I'm having trouble getting from the 555 to the scr/igbt however, as i'm pretty sure the gate needs to be connected to voltages that would fry my 555. any help? will post diagram soon. thanks.