Inductively coupled energy and communication apparatus

An inductively coupled energy and data communication apparatus for a steering column assembly supporting a steering wheel assembly including an electrically actuated air bag inflator, the apparatus comprising:

• a transformer having primary and secondary windings in spaced adjacency, said primary winding being non-rotatably secured to the steering column assembly and said secondary winding being rotatably secured to the steering column assembly for rotation with the stewing wheel;
• a primary energization circuit for energizing the primary winding at a first frequency during predetermined non-deployment conditions and at a second frequency during predetermined deployment conditions;
• first and second loads selectively coupled to the secondary winding in accordance with predetermined binary patterns, the first load providing a first reflected impedance to the primary winding corresponding to a first binary state and the second load providing a second reflected impedance to the primary winding corresponding to a second binary state;
• circuitry for decoding the first and second reflected impedances into the first and second binary states corresponding to the predetermined binary patterns;
• an energy storage capacitor;
• circuitry responsive to the first frequency to store charge to the energy storage capacitor from the secondary winding during non-deployment conditions;
• and,
• circuitry responsive to the second frequency for discharging the stored charge through the inflator during deployment conditions to deploy the air bag.

A method for transferring energy and data between a vehicle side wiring harness and rotating portions of a steering column assembly including a charge storage capacitor and airbag inflator module, the method comprising:

• providing an inductive coupling including primary and secondary windings, the primary winding being associated with the vehicle side wiring harness and the secondary winding being associated with the rotating portions of the steering column assembly;
• oscillating the primary winding at a first frequency during periods of vehicle operation wherein predetermined airbag deployment conditions are not satisfied;
• oscillating the primary winding at a second frequency during periods of vehicle operation wherein the predetermined airbag deployment conditions are satisfied;
• transferring energy from the secondary winding to the charge storage capacitor when the secondary winding oscillates at the first frequency;
• discharging energy from the charge storage capacitor to the airbag inflator to deploy the air bag when the secondary winding oscillates at the second frequency.