Abstract: A variable ramp voltage generated by a first 555 timer is applied to the control electrode of a second 555 timer for controllably varying the delay function of the second timer. The second timer is triggered in accordance with the motion to be observed, several trigger signals being applied during each ramp. The output signals from the second timer are thus timed at progressively longer intervals from the respective input signals during each ramp. The output signals are applied to trigger a stroboscope, producing a cinematographic slow motion view of a selected portion of the motion under observation.

Abstract: A control circuit for triggering a stroboscope repetitively at successively longer intervals following successive input signals. It enables visual observation of a selected portion of the travel of a repetitively moving object with a cinematic slow motion effect. The circuit is relatively simple and includes a variable delay device, and means for varying the delay produced by it in accordance with a ramp voltage that has a period spanning several of the input signals, that is, several repetitions of the complete motion of the object to be observed.

Abstract: A detent of low mass consisting of a wire bent to form a torsion spring with laterally extending arms shaped for abutment with the moving object to be stopped. The tips of the arms are covered with a compressible, resilient material that absorbs the initial shock of impact until the pre-load is taken up and the arm begins to move.