PURPOSE: To connect equipments to a bus as many as possible by closing a switching means only for a previously fixed period after transmitting/receiving a signal pulse on a transmission line to remove influence due to inductance of a transformer.
CONSTITUTION: Current in a coil is made to flow into a resistor 206 in a reverse direction at the time of opening a switch 202 and the product of a current value and a resistance value at that time becomes a back swing voltage. Therefore, the back swing voltage is reduced by equivalently reducing the resistance value of the resistor 206 at the time of opening the switch 202. Namely, a switch 204 is connected in parallel with the resistor 206, and after opening the switch 202, the switch 204 is closed for a fixed period. Consequently, the reliability of communication is improved and equipments more than ordinary ones can be connected to the bus by using the same transformer.
TAJIMA TAIJI
IMAIZUMI TAKESHI
