Abstract: A distributed airbag firing system (10) includes a controller (12) receiving sensor signals from a sensor (20) over a two-wire bus (18). The controller provides a firing command over to the two-wire bus to a squib driver circuit (26), which provides the firing current necessary to detonate a squib device (32) and inflate the airbag. The squib driver circuit includes a rectifier (42) with its first and second inputs interchangeably connected to the two-wire bus. The rectifier circuit converts the voltage orientation on the first and second conductors to a positive potential on a first output conductor and a negative or ground potential on a second output conductor. The interchangeability of the first and second inputs of the rectifier to the two-wire bus makes the connection arbitrary and fail-safe.

Abstract: The present invention discloses a battery charging device adapted to be connected to a battery having a positive and a negative terminal for supplying a direct current to the positive terminal of the battery. This device comprises an alternating current supply means, such as a transformer, connected to a power supply for providing alternating current, such as a wall socket. A charge current supply controller means is connected to the secondary winding of the transformer. The charge current supply controller means comprises two pairs of silicon controlled rectifiers ("SCR") and a SCR interface circuit. The secondary of the transformer is also connected to the SCRs. A processor which is connected to the SCR interface circuit determines which pair of SCRs will supply direct current to the battery. The processor, which is connected to the output of the polarity sensing detector, decides which pair of SCRs will be the conduit for the current to the battery based on the output of the polarity sensing detector.