Horn actuator incorporating a transducer in a steering wheel

Claim 1

An apparatus for actuating an electrical device in response to pressure applied to a deformable air bag cover door, comprising: an air bag cover door deformable by hand pressure; a force sensitive resistor attached to said cover door such that its resistance changes upon pressure being exerted on the cover door; and a switching circuit connected to said force sensitive resistor for changing said switching circuit's conductive state in response to a change in the resistance of said force sensitive resistor, said switching circuit comprising a transistor switch controlled by said force sensitive resistor with said transistor switch having a first current carrying terminal for coupling said transistor switch to the electrical device, a second current carrying terminal coupled to a common ground, and a driving terminal coupled to said force sensitive resistor; wherein said transistor switch is operable to provide a low impedance path from said first current carrying terminal to said second current carrying terminal when said force sensitive resistor undergoes a change in resistive value; and wherein said switching circuit further comprises a resistive element having a first terminal coupled to said first current carrying terminal of said transistor switch and a second terminal for coupling said transistor switch to the electrical device, such that current flowing from the electrical device flows through said resistive element and said first current carrying terminal.

Claim 2

An apparatus for actuating an electrical device in response to pressure applied to a deformable air bag cover door, comprising: an air bag cover door deformable by hand pressure; a force sensitive resistor attached to said cover door such that its resistance changes upon pressure being exerted on the cover door; and a switching circuit connected to said force sensitive resistor for changing said switching circuit's conductive state in response to a change in the resistance of said force sensitive resistor, said switching circuit comprising a transistor switch controlled by said force sensitive resistor with said transistor switch having a first current carrying terminal for coupling said transistor switch to the electrical device, a second current carrying terminal coupled to a common ground, and a driving terminal coupled to said force sensitive resistor; wherein said transistor switch is operable to provide a low impedance path from said first current carrying terminal to said second current carrying terminal when said force sensitive resistor undergoes a change in resistive value; and wherein said switching circuit further comprises a resistive element having a first terminal coupled to said first current carrying terminal of said transistor switch and a second terminal for coupling said transistor switch to the electrical device, such that current flowing from the electrical device flows through said resistive element and said first current carrying terminal.