| 摘要 |
PURPOSE:To prevent the malfunction even at the time of continuous transmission of a sine wave by superposing a pulse discrimination signal at a peak value occurrence point of a repeat signal in a transmission part and allowing only the signal in the vicinity of the discrimination signal reception timing to pass through in a reception part. CONSTITUTION:The sine wave generated by a sine wave generating circuit 12 is supplied to a discriminating circuit 14 and the period is discriminated, and a signal generating circuit 15 generates a pulse signal wave based on this period, and this wave is synthesized with the sine wave generated by the sine wave generating circuit 12 by a primary coil driving circuit 13. That is, the pulsed signal wave is superposed at the peak point of the sine wave. Consequently, an induced voltage waveform which is sharp in this part by the quick signal change is generated in a coil 20 of the reception part. A gate circuit 23 outputs a time pulse, which includes the pulsed signal occurrence point and is longer than the duration of the pulsed signal, to this signal. The voltage generated by a rectifying circuit 21 is supplied to the discriminating circuit 24, and this circuit 24 discriminates the signal only when the pulse from the gate circuit 23 is supplied. |
