| 摘要 |
PURPOSE:To establish the detection circuit which stably operates not subject to the effect of noise intruded in the magnetostriction wires, by constituting the automatic exciting circuit with the loop including the excitation pulse generation circuit, exciting means, magnetostriction wire, reception means and delay line. CONSTITUTION:The delay circuit DL is placed between the comparison amplifier OP and the exciting pulse generator OS, further the D/A converter DA is placed at the output of the counter CU, and the signal corresponding to the displacement of the moving part 3 is obtained in analog signal. Thus, the generator OS outputs new exciting pulse PE delayed by the delay time tau after the detection signal e, by providing the delay circuit DL. By taking the delay time tau longer than the time required for the reciprocal of the total length of the magnetostriction line 1 with ultrasonic signal, the noise signal or reflection signal caused in the magnetostriction line 1 is masked with the delay circuit DL, allowing to make stable the operation. |
