(JP9290704-A)      Occupant safety device for a car has protection mechanism comprising a step-up switch to transform the battery voltage, a safety capacitor connected to the step-up switch and the battery, an accident monitoring device which monitors the slowing down of the car to determine whether to generate an accident signal which then activates the device for firing of the car air bag.    A switching circuit is provided that has two roles, firstly to block the connection between the safety capacitor and the accident monitoring device when there is sufficient voltage available from the car battery and secondly to connect the safety capacitor to the accident monitor, within the required time, when there is not sufficient voltage.    USE/ADVANTAGE -   Activation of a car air-bag following an accident. The switching circuit necessary to switch between the battery and safety capacitor can be reduced in size (and therefore cost and manufacturing difficulty) as it is not necessary to connect the safety capacitor directly to the firing circuit and the monitoring device.    (US5995891-A)      Occupant safety device for a car has protection mechanism comprising a step-up switch to transform the battery voltage, a safety capacitor connected to the step-up switch and the battery, an accident monitoring device which monitors the slowing down of the car to determine whether to generate an accident signal which then activates the device for firing of the car air bag.    A switching circuit is provided that has two roles, firstly to block the connection between the safety capacitor and the accident monitoring device when there is sufficient voltage available from the car battery and secondly to connect the safety capacitor to the accident monitor, within the required time, when there is not sufficient voltage.    USE/ADVANTAGE -   Activation of a car air-bag following an accident. The switching circuit necessary to switch between the battery and safety capacitor can be reduced in size (and therefore cost and manufacturing difficulty) as it is not necessary to connect the safety capacitor directly to the firing circuit and the monitoring device.    (JP3090037-B2)      Occupant safety device for a car has protection mechanism comprising a step-up switch to transform the battery voltage, a safety capacitor connected to the step-up switch and the battery, an accident monitoring device which monitors the slowing down of the car to determine whether to generate an accident signal which then activates the device for firing of the car air bag.    A switching circuit is provided that has two roles, firstly to block the connection between the safety capacitor and the accident monitoring device when there is sufficient voltage available from the car battery and secondly to connect the safety capacitor to the accident monitor, within the required time, when there is not sufficient voltage.    USE/ADVANTAGE -   Activation of a car air-bag following an accident. The switching circuit necessary to switch between the battery and safety capacitor can be reduced in size (and therefore cost and manufacturing difficulty) as it is not necessary to connect the safety capacitor directly to the firing circuit and the monitoring device.