送受信回路

Abstract

To provide a transmission / reception circuit that can increase applied voltage during transmission compared to the conventional arts while maintaining the gain of a transmission / reception sensor during reception.SOLUTION: A transmission / reception circuit comprises: an amplifier whose non-inverting input terminal is connected to a voltage signal output terminal of a signal generator; a feedback resistor having one end connected to an output terminal of the amplifier and the other end connected to an inverting input terminal of the amplifier; an input resistor having one end connected to the inverting input terminal of the amplifier and the other end connected to the other end of the feedback resistor; a switch having one end connected to one end of the feedback resistor, and the other end connected to the other end of the feedback resistor; a control circuit for the switch; a second switch having one end connected to the other end of the input resistor, and the other end connected to one end of a first transmission / reception sensor capable of transmitting and receiving a transmission wave based on a voltage signal output from the signal generator; and a third switch having one end connected to the other end of the input resistor, and the other end connected to one end of a second transmission / reception sensor capable of transmitting and receiving a transmission wave based on the voltage signal output from the signal generator.SELECTED DRAWING: Figure 1

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