Abstract: An electronic crash sensor which can operate appropriately in response to any form of crash of any vehicle, more especially to a high speed oblique or pole crash of a vehicle which has a less rigid body or to a compound crash which is compound of various forms of crash, to say nothing of a high speed oblique or pole crash of a vehicle which has a normal rigid body. An input acceleration waveform from an accelerometer is processed to peak cut any portion thereof lower than a predetermined value. Then, the value obtained by the said peak cutting is time integrated. Then, a time integrated value of a predetermined function is subtracted from the value obtained by the said time integration.

Abstract: To detect an impact due to a shock with high precision and stability, a shock sensor is employed which provides a sufficiently long closure interval of a contact of a reed switch (1) enough to carry out signal processing. A gap between an outer surface of a magnet (2) and an inner wall (8) of a housing (7) defining a passage for the magnet (2) comprises a first gap (G1) between a stationary position and an activating position and a second gap (G2) between the activating position and a stop position. The inner wall (8) is formed so that the first gap (G1) is greater than the second gap (G2). The velocity of the magnet (2) is lower when travelling in the second gap (G2) than the velocity in the first gap (G1) because air resistance is greater in the second gap (G2). Accordingly, the closure interval is increased.

Abstract: An electronic crash sensor which can operate appropriately in response to any form of crash of a vehicle. An input acceleration waveform from an accelerometer is first processed to peak cut any portion thereof lower than a predetermined value. Then, a value obtained such peak cutting is time integrated. Then, a time integrated value of a predetermined function is subtracted from a value obtained by such time integration. Then, the value of the acceleration waveform thus obtained is compared with a predetermined time function value, and when the former is higher than the latter, a triggering signal is delivered to a trigger circuit to trigger operation of a passenger protecting apparatus such as an air bag of the vehicle.