Vehicular passenger protection system

摘要

A passenger protection system for a motor vehicle having a supplementary power supply for operating the protection system has a relatively small capacity. This enables the system to be made more compact and lighter. The vehicle includes a battery disposed in parallel with two diodes via a key switch. Output form one diode charges a back-up condenser. Discharge energy from the back-up condenser is provided to the airbag circuit via a switch. The output of the other diode is also provided to the airbag circuit. The switch is controlled by a detection circuit that judges whether energy is supplied from the back-up condenser to the airbag circuit. An ignition device is set so that the airbag may be operated via a switch which is turned on with deceleration so that the power is provided responsive to a collision determination.