Patent ID: 7917263

Claim:
An activation system for a passenger protection device mounted in a vehicle, the system comprising: a pair of communication wires; a central unit connected to the communication wires for detecting currents flowing in the communication wires and controlling activation of the passenger protection device based on detected currents; and a satellite unit including a sensor and connected to the communication wires to be located away from the central unit, the satellite unit varying the currents flowing in the communication wires based on output data of the sensor, wherein the central unit includes a pair of current detection means connected to the pair of communication wires for detecting the currents in the communication wires, respectively, to detect the output data of the sensor based on the detected currents, and wherein one of the pair of current detection means is provided to detect a current, which flows from the central unit to the satellite unit through one of the pair of communication wires, and the other one of the pair of current detection means is provided to detect a current, which flows from the satellite unit to the central unit through the other one of the pair of communication wires.