Electric ignition circuit for a motor vehicle occupant protection system
First Claim
1. An electric firing circuit for a motor vehicle occupant protection system, with at least two firing stages for triggering an occupant protection component firing in at least two stages, each firing stage having at least one firing pellet and a switching element which is connected in series with said firing pellet for control by a control device, and with a safety switch, which responds to a physical parameter and releases a current feed to at least one of the firing stages when a certain threshold value is exceeded, but otherwise blocks said feed, the second firing stage, provided for the firing of the second stage of the occupant protection component, being connected to an electronic safety switching element, the control terminal of which is coupled to the safety switch and placed into the switched-through state by the safety switch, and a holding circuit connected between the safety switch and the control terminal of the switching element, the holding circuit being activated and applying a driver signal to the control terminal with a certain minimum time period when the safety switch closes.
2 Assignments
0 Petitions
Accused Products
Abstract
Two different switching signals for switching through the safety switching element (22) for the second firing stage of an occupant protection component which can be triggered in multiple stages are formed in the control device (3). The two switching signals are emitted to different outputs (14, 16) of the control device (3) and then subjected to an AND operation.
22 Citations
16 Claims
- 1. An electric firing circuit for a motor vehicle occupant protection system, with at least two firing stages for triggering an occupant protection component firing in at least two stages, each firing stage having at least one firing pellet and a switching element which is connected in series with said firing pellet for control by a control device, and with a safety switch, which responds to a physical parameter and releases a current feed to at least one of the firing stages when a certain threshold value is exceeded, but otherwise blocks said feed, the second firing stage, provided for the firing of the second stage of the occupant protection component, being connected to an electronic safety switching element, the control terminal of which is coupled to the safety switch and placed into the switched-through state by the safety switch, and a holding circuit connected between the safety switch and the control terminal of the switching element, the holding circuit being activated and applying a driver signal to the control terminal with a certain minimum time period when the safety switch closes.
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16. A motor vehicle occupant protection system with at least one occupant protection component triggering in multiple stages and is to be triggered in the event of an accident of the motor vehicle, in particular an airbag or a belt tensioner, and a firing circuit for triggering the occupant protection component, characterized in that the firing circuit has at least two firing stages for triggering an occupant protection component firing in at least two stages, each firing stage having at least one firing pellet and a switching element which is connected in series with said firing pellet for control by a control device, and with a safety switch, which responds to a physical parameter and releases a current feed to at least one of the firing stages when a certain threshold value is exceeded, but otherwise blocks said feed, the second firing stage, provided for the firing of the second stage of the occupant protection component, being connected to an electronic safety switching element, the control terminal of which is coupled to the safety switch and placed into the switched-through state by the safety switch, and a holding circuit connected between the safety switch and the control terminal of the switching element, the holding circuit being activated and applying a driver signal to the control terminal with a certain minimum time period when the safety switch closes.
Specification