| 摘要 |
PURPOSE:To separate a weight and recover it securely even if a receiving system is failed by judging the legality of the receiving system periodically, and even if the receiving system in failed, automatically operating a releasing mechanism through a release control circuit. CONSTITUTION:The oscillation frequency of a false signal generating circuit 13 is selected as the frequency of an antiresonance point of a transmitter/ receiver 1. If a signal is applied from the circuit 13 to the transmitter/receiver 1 when the transmitter/receiver is not failed, high voltage of Q times is applied to both the ends of the transmitter/receiver 1. When the transmitter/receiver 1 is defective (e.g. damage of a vibrator), a low voltage is applied to both the ends. The voltage applied to both the ends of the transmitter/receiver 1 is amplified and applied to a level detecting circuit 16. When an attenuator 14 is set up so that a signal is outputted from the circuit 16 when the frequency of the antiresonance point is applied, an output is generated from the circuit 16 only when the transmitter/receiver 1 is normal. The output of the circuit 16 is applied to a release judging circuit 17, and only when the output of the circuit 16 is not applied at the time of callibration, the circuit 17 outputs a release command. |
