Abstract: A vehicle weight classification system recognizes the various factors that influence system performance. Some of the factors are compensated for using analog signal processing circuitry or techniques. Other factors are compensated for using digital signal processing techniques. The unique combination of analog and digital approaches, rather than pure analog or pure digital, provides an effective solution at addressing the various factors that influence signals and system performance in a vehicle weight classification system while keeping the cost and complexity of the system within acceptable limits.

Abstract: A system for controlling air bag deployment in vehicles includes the capability of accommodating varying inductants values in the air bag circuit. Wire harnesses that couple air bag components have varying characteristics, such as length, which affect the inductants value of the circuit. The inventive arrangement utilizes charge and discharge times of at least one capacitor for measuring the inductants of a particular circuit. The system includes a controller that accommodates the inductants by introducing an appropriate delay in the firing circuit signal to operate the air bag.

Abstract: A configuration containing a sensor for accident detection, a downstream control device, a downstream firing device and a firing element for a restraint device is described. The control device generates a control signal that is composed of a first current in one direction and a subsequent second current in the opposite direction. The firing device has an integration device for integrating the first current, and also an enable device, which is connected downstream of the integration device and serves for enabling firing of the firing element. The firing of the firing element is effected by the second current when or after a limit value of the integral of the first current has been reached.

Abstract: The inductor-type converter has an inductor that is fed by a supply voltage source Vbat. The inductor is charged via electronic switching elements and discharged via a load impedance. The inductor is connected in the bridge path in an H-bridge topology formed from five electronic switching elements. The electronic switching elements are driven periodically or cyclically by an electronic control unit. The voltages at the two capacitive elements are different from the supply voltage Vbat.

Abstract: An igniter for igniting a reactive material has a conductor for conducting power and communication signals to and from the igniter. A controller is located within the igniter. The controller is preferably an application specific integrated circuit (ASIC). The controller has communication means for communicating with a master controller located remote from the igniter. The controller also has diagnostic means for comparing established parameters for components of the igniter to predetermined limits and sending fault warning messages and integrity status messages to the master control unit. The controller also further has means for receiving a unique igniter activation command from the master control unit and sending an activation signal to an igniter activation means that couples the energy stored in an energy storage capacitor to a heating member that ignites a reactive material.

Abstract: A switched capacitor circuit for delivering electrical triggering energy to an airbag squib of a supplemental restraint system for a vehicle, or a plurality of such airbag squibs, employs a switching arrangement on both sides of the airbag squib. An energy storage element, which may be a capacitor having stored therein a quantum of energy sufficient to fire the airbag squibs is coupled thereto by a substantially series pair of electronic switches connecting each terminal of the storage capacitor to each terminal of the airbag squib arrangement. A further capacitor is coupled across the airbag squib arrangement, electrically intermediate of the substantially series pairs of electronic switches. A still further capacitor is coupled across the airbag squib arrangement itself. This arrangement can withstand plural short-circuit false conditions, including short-circuits to ground or to supply potential at the terminals of the airbag squib arrangement itself.

Abstract: A control arrangement for a deployable airbag of a vehicle is provided with first and second airbag controllers for receiving a fault signal at the first airbag controller, and for producing at the second airbag controller a deployment command signal that indicates that the deployable airbag is to be deployed. The second airbag controller receives the deployment command signal, and is provided with a communication controller for receiving the deployment command signal, a squib for firing in response to the deployment command signal whereby the deployable airbag is deployed, and an energy transfer arrangement coupled to the communication controller and the squib for transferring a deployment energy to the squib in response to the deployment command signal. The squib is configured to require a predeterminable minimum quantum of energy to effect the firing thereof in response to the deployment command signal.

Abstract: A control arrangement for a deployable airbag of a vehicle is provided with a squib for firing in response to a deployment command signal whereby the deployable airbag is deployed. Bilateral communication is effected between the control arrangement and an airbag electronic controller. Electrical energy and data, including the deployment command signal are conveyed to the control arrangement, and at least self-diagnosis information is conveyed to the airbag electronic controller. The squib is configured to require a predeterminable minimum quantum of energy to effect the firing thereof in response to the deployment command signal. A heater provides a radiated preheat to the squib, whereby the predeterminable minimum quantum of energy applied to effect firing of the squib is exceeded by a combination of the first electrical energy and the radiated preheat energy. The squib and the preheater preferably are both formed on a silicon substrate using a conventional integration process.

Abstract: A circuit for testing the leakage resistance of a circuit point. Particularly in the case of circuits where safety is important, a circuit point, particularly an output terminal of an integrated circuit, should be tested for a leakage resistance relative to ground and/or a voltage to provide an early detection of an imminent failure condition. To this end, at least one test current is fed into the circuit point and the voltage at the circuit point is monitored by means of a comparator. When the leakage resistance decreases below a permissible value the voltage at the circuit point decreases, which can be detected by the comparator. For monitoring a leakage resistance relative to both poles two opposite test currents are applied and the comparator is constructed as a window comparator.