| 摘要 |
PURPOSE:To secure an interface despite the trouble of a power supply by sharing a power supply unit which supplies the electric power to the terminal resistance of each device to be controlled and another power supply unit which supplies the electric power to a control circuit by means of the same unit. CONSTITUTION:An interface circuit consists of a controller 1, plural devices 31-34 to be controlled, the 1st power supply unit 20, and one or more pieces of the 2nd power supply units 21-24. The controller 1 contains a driver circuit that forms a chained interface circuit which is driven by an open collector. The devices 31-34 contain receiver circuits 41-44 and terminal resistances 51-54 respectively. The unit 20 supplies the power to the resistances 51-54 connected to the circuits 41-44 from the same power supply via the driver circuit and at least a single device to be controlled. While the power supply units 21-24 supply the power to those devices to be controlled excluding the one that receives the supply of power from the unit 20. |
