[wasp69]

Another approach is to use an overpressure switch.

Now I am not a demo guy by no means so I hope you will entertain a few questions. I could see where mercury in a glass bulb, much like a home heating and cooling thermostat, could be used to go off if the vibration is strong enough. Could you please elaborate on an overpressure switch? Is it triggered by a change in pressure kind of like a nuke warhead that senses what kPA it is in and when to detonate?

[MadRobotArtist]

If everyone on this thread would read a book called, "The Oklahoma City Bombing and the Politics of Terrorism", there wouldn't be any questions as to who was responsible for this. I encourage EVERYONE to read this book. Then take a hard long look at what happened September 11th.