摘要 |
A transformer used to connect an electro-acoustic transducer to a transmitter and a receiver in a pulse-echo ranging system has a first winding connected to the transducer, and second and third windings connected in parallel to the transmitter and the receiver. The second winding has back-to-back diodes in series with it, and the third winding has several times more turns than the second winding, so that with high amplitude signals, as during transmission, the diodes conduct and render the second winding effective. With low amplitude signals, as during reception, the diodes isolate the second winding and the third winding acts to provide a relative step-up of the amplitude of the received signals.
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