Patent ID: 7418330
Filing Date: 2008-08-26
Classification: B60R

Abstract:
1. An electronic control unit for controlling a dual-stage firing system of a vehicle occupant restraint system, comprising: first and second output terminals adapted for connection to said dual-stage firing system; and a current supply circuit for initially supplying a forward current to a first stage of said dual-stage firing system through said output terminals when an impact is received, and subsequently supplying a reverse current to a second stage of said dual-stage fixing system through said output terminals in a direction opposite to said forward current wherein said current supply circuit comprises: a first series circuit of first and second switching elements connected between high and low voltage power lines to form a first circuit node between said first and second switching elements, said first circuit node being connected to said first output terminal; a second series circuit of third and fourth switching elements connected between said high and low voltage power lines in parallel with the first series circuit to form a second circuit node between said third and fourth switching elements, said second circuit node being connected to said second output terminal; and control circuitry for exclusively activating said first and fourth switching elements in response to said impact, for generating a forward voltage across said output terminals, and subsequently exclusively activating said third and second switching elements for generating a reverse voltage across said output terminals in a direction opposite to said forward voltage.