A rocket fuse with delayed-action arming comprises a fixed cylinder containing microballs and a spring-loaded plunger in the cylinder tends to force the balls out through a calibrated orifice. In the stored position the orifice is closed by a closing ring which can slide on the cylinder with a helical movement to open the orifice at the end of such movement. The movement takes place due to inertia when the rocket is launched and the ensuing movement of the plunger is used to arm the detonator.
An apparatus for generating an electrical power upon an acceleration of the apparatus is provided. The apparatus including: a piezoelectric member having at least a portion thereof formed of a piezoelectric material; and a mass-spring unit having a spring element attached to the piezoelectric material and configured to compress and/or elongate within a predetermined limit, the mass-spring unit further having a mass offset from the piezoelectric material; wherein the mass-spring unit is configured to vibrate within the predetermined limit, upon the acceleration of the apparatus, the vibration applying a cyclic force to the piezoelectric member to generate an output power from the piezoelectric member.
