yeah, planned on using the coil to feed an npn.
the downswing will be the first swing, ie: the moment we start the pendulum in motion. we'd leave the timer's off untill the pendulum reachs the top of its swing. then turn the timer on. so the first swing the coil ever see's is a downswing.
since the freq/period of a pendulum doesnt change, i know exactly how long the positive and negative duty cycles must be. just need to keep the delay long enough, so the bob passes the oppsite side of the coil before the delay runs out. should actually keep the delay long enough so the bob is almost to the trigger spot again. that'll keep any outside sources from induceing thru the coil prematurly