Device and method for supplying the triggering device of an occupant restraint system with power
View Patent ↗The invention relates to a device that comprises a plurality of energy stores and a driver circuit. Said driver circuit is supplied by at least two of the energy stores via a selecting circuit in such a manner that the driver circuit is always supplied by the energy store that has the highest voltage as compared to the remaining energy stores.
1. A device for supplying power to a firing unit of a vehicle-occupant restraint system, comprising:
a plurality of switches formed as MOS transistors having gate terminals;
a plurality of energy storage devices;
a control device;
a driver circuit for the vehicle-occupant restraint system, the driver circuit coupled to the gate terminals of the MOS transistors;
a selector circuit supplying the driver circuit with a voltage from one of the energy storage devices that is higher than a voltage of any other one of the energy storage devices; and
a charge pump connected between the selector circuit and the driver circuit.
2. The device according to claim 1 , wherein the selector circuit includes a diode matrix.
3. The device according to claim 1 , wherein: one of the energy storage devices is a part of a firing circuit of a front airbag of the vehicle-occupant restraint system.
4. The device according to claim 1 , wherein: one of the energy storage devices is a part of a firing circuit of a side airbag of the vehicle-occupant restraint system.
5. The device according to claim 1 , further comprising:
a step-up converter for generating a firing voltage for the vehicle-occupant restraint system;
the step-up converter including one of the energy storage devices.
6. The device according to claim 1 , further comprising:
a step-up converter for generating a supply voltage for the control device;
the step-up converter including one of the energy storage devices.
7. The device according to claim 1 , wherein the charge pump includes an energy storage device.
8. The device according to claim 1 , wherein the energy storage devices are capacitors.
9. A method for supplying power to a firing unit of a vehicle-occupant restraint system, comprising:
using switches to feed energy to the firing unit from a first storage device, the switches being MOS transistors having gate terminals;
providing a driver circuit for actuating the MOS transistors and coupling the driver circuit to the gate terminals of the MOS transistors;
using a selector circuit to supply the driver circuit with a voltage from one of the energy storage devices that is higher than a voltage of any other one of the energy storage devices.