Land mine

1. A detonating circuit comprising a coil responsive to an external magnetic field, a vibration responsive switch connected in parallel with said coil having a closed position and an open position, said switch responsive to external vibration for vibrating between said open and closed positions, an electronic amplifier coupled to said switch and to said coil and biased to provide constant amplitude pulses having periods equal to the vibration rate of said switch, an impulse forming circuit coupled to said amplifier having means for storing a predetermined number of said pulses, an explosive primer, means coupled to said impulse forming circuit and to said primer for actuating said primer when an impulse of predetermined energy is generated in response to the receipt of said predetermined number of pulses.