| 摘要 |
PROBLEM TO BE SOLVED: To supply power and to perform communication by connecting a center device and a satellite device of an on-vehicle electronic control element by a 2-wire. SOLUTION: An air bag device 20 receives a communication signal from a satellite device 22 at a separated location so as to perform the control of expanding an air bag 43 in a center device 21. The satellite device 22 uses a power supply line 23 for the power supplied from the center device 21 and disconnects an output element 44 so as to perform superimposed current communication. A power supply voltage supplied to the satellite device 22 is stabilized by a center power source 29. The current communication is received by amplifying the potential difference across the terminals of a current detection resistor 25 by means of a differential amplifier 35, which is discriminated in a comparator 37 and inputted to a microcomputer 31. When a current cutting circuit 40 is operated, the current supplied to the satellite device 22 can be cut off. |
