Two-line transmission circuit for digital signal - has disturbance-free characteristics with one signal line and one reference line

摘要

A circuit is used to transmit non-symmetrical digital signals along long lines. It is free from the effects of disturbances. The circuit has at least two lines. One line is used by the signal to be transmitted and the other line is used by a voltage reference. The signal transmitter has a constant current circuit for the signal. The receiver has a terminal resistance which produces a voltage drop between the signal line and the voltage reference line. The voltage reference is chosen above a threshold and has a value which does not affect the signal transmitted. The receiver is actuated by the voltage drop produced by the signal.