Redstone circuits/Pulse/nor-gate fed

1-Wide NOR-Gate Falling Edge Detector

1×4×4 (16 block volume)
1-wide, silent
circuit delay: 2 ticks
output pulse: 1 tick

In-line NOR-Gate Falling Edge Detector

2×4×3 (24 block volume)
silent
circuit delay: 1 tick
output pulse: 1 tick