0 04 msec now even if we assume a similar acceleration profile in the gun barrel but spread it over a time duration of 8 msec close to what is experienced in many large caliber guns then the impulse experienced during the firing is 8 0 04 or 200 times larger than that experienced during a drop over a hard surface this is obviously a conservative estimate and the actual ratio can be expected to be much higher since in most situations the round is not expected to land perfectly on its base and on a very hard surface and that the firing acceleration is expected to be significantly larger than those experienced in an accidental drop the above example clearly shows that by measuring the impact impulse accidental drops can be readily differentiated from the firing acceleration by the processor 208 this characteristic of the present piezoelectric based power generation units 100 can be readily used to construct a safety feature to prevent arming of the fuzing during accidental drops and or to take some other preventive measures this safety feature can be readily implemented in the electrical energy collection and regulation electronics of the power source or in the fuzing electronics e g the processor 208 can have an input into the electrical energy collection and regulation electronics 202 of the power source or in the.