A seat occupant weight sensing system includes load cells that receive the weight of a seat occupant. The break location enables the conduit or cable to be broken. 5 mm, the intermediate layer has a gage of 1. In the latter, if the decrypted second number satisfies a second condition, the encrypted data are transmitted to the second card so that the latter calls up the application, decrypts the encrypted data using the decrypted second key and installs said data. The data transmitting apparatus controls the amplitude of the sine component of the angle-modulated real signal by a gain that varies with a control signal and then transmits the real signal.