US Patent 9207054 Solid state ignition safety device

A solid state ignition safety device for rocket assisted projectiles having a piezoelectric generator that charges a capacitor during the initial acceleration of the projectile by the launching propellant charge. The capacitor is then discharged after a delay to ignite an initiator, which ignites the rocket motor of the projectile. A time delay circuit can be integrated into the ignition safety device to further delay the ignition of the initiator until the projectile has reached the ideal point in its trajectory to ignite the rocket motor.