| 摘要 |
PURPOSE:To transmit a driving signal, a receiving signal, and power supply through one line without mutual interference, by transmitting the receiving signal of an ultrasonic wave receiving oscillator, which is provided in an ultrasonic sensor part, to an ultrasonic controlling part through the transmission line of the driving signal after amplifying this receiving signal. CONSTITUTION:When the signal is L-level by an ultrasonic transmission signal generating circuit 1, a transistor TR 3 is turned off, and the voltage between the emitter of a TR 5 and the earth becomes Vcc, and this voltage Vcc charges a capacitor 25 through a diode 19 and a resistance 24 and is supplied as the power source of an amplifier 22. When the ultrasonic transmission signal generating circuit 1 becomes the oscillation state, signals outputted by TRs 5 and 7 pass through a connection cord 11 and diodes 16 and 17, and the driving dignal is applied to an ultrasonic oscillator 20 for transmission to send ultrasonic waves for a certain time. Reflected waves are converted to an electric signal by the ultrasonic oscillator 23 for reception, and the signal amplified by the amplifier 22 is inputted to an ultrasonic receiving signal processing circuit 14 and is processed. |
