Abstract: A starting device integrates an output signal of an acceleration sensor by a band-pass integrating means while restricting an upper limit of the output signal in a specified frequency range by an upper limit restricting means, and is provided with a comparing means for outputting a starting signal when the integrated value is larger than a predetermined threshold value. In this way, the starting device is certainly started by an acceleration waveform of collision that must start the device. Further, the device is not influenced by vibration components caused immediately after the beginning of collision with respect to a low-speed collision such as 8 mile/hour frontal collision that must not start the device.

Abstract: A starting apparatus for a passenger protecting apparatus includes a collision deciding unit, a control unit, and a trigger. The collision deciding unit makes a collision decision depending upon output of an acceleration sensor which detects acceleration at a time of collision. The control unit controls generation of a starting signal based upon a difference between output of a decelerating direction integrating unit, which integrates the acceleration signal of the acceleration sensor in the decelerating direction, and output of accelerating direction integrating unit, which integrates the acceleration signal of the acceleration sensor in an acceleration direction. The trigger outputs the starting signal based on output of the collision deciding unit and output of the control unit.