The ability of the OS to suppress common-mode (coming simultaneously to both inputs) the voltage allows you to isolate the useful weak signals on the back of strong interference. On the figure shows a diagram of the device (its principle of operation is based on the specified the property OS) that can transmit signals in both directions on one coaxial cable (the elements in the right part of the diagram has a positional designations, beginning with the number 11).
The input signals A and b through the buffer amplifiers (DA1, DA11) with a coefficient of transmission 1 and the resistors R5, R15 go on line. It is connected to the inputs of the opamps IN 2 and DA 12, amplifying the differential signal and common mode suppressing. Change resistance trimming resistors R8 and R18 is possible to achieve suppression unwanted signal at 50...55 dB.
The device can be used to transmission of analog and digital signals.
Note. Domestic analogue Oh 741 COD.
Literature
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