Patent ID: 7564324

Claim:
A data bus system, comprising a data bus and a terminal; wherein the data bus has a first data line and a second data line; wherein the terminal is connected via a directional coupler to the first and the second data lines in order to transmit and receive data via the data bus; wherein the terminal has a transmitter and a receiver, the receiver isolated from the transmitter by the directional coupler; wherein the direction coupler includes a transformer having a primary coil, a first secondary coil, and a second secondary coil; wherein one end of an impedance is coupled to the first and second secondary coils of the transformer and another end of the impedance is coupled to the transmitter and the receiver; wherein the directional coupler relays an input signal coming from the bus line to the transmitter and the receiver; wherein the directional coupler relays an output signal going from the transmitter to the data bus, but not to the receiver.