Patent ID: 7176840

Claim:
An inductor with variable length comprising: a. a traveler plate with a central axis and an electrical connection; b. a fixed plate with a central axis and an electrical connection, the fixed plate coaxially arranged substantially parallel to and a desired distance from the traveler plate; c. an electrical conductor arranged in a flexible helical coil with a multiplicity of windings substantially around a central axis, a first electrical connection, and a second electrical connection, the first electrical connection attached to the traveler plate electrical connection, the second electrical connection attached to the fixed plate electrical connection, the conductor arranged in the space between the traveler plate and the fixed plate such that moving the traveler plate away from the fixed plate moves the inductor coils symmetrically apart and moving the traveler plate towards the fixed plate moves the inductor coils symmetrically closer together; d. means for moving the traveler plate away from or towards the fixed plate; e. an electrical conductor for connecting the traveler plate electrical connection to an electric circuit; and f. an electrical conductor for connecting the fixed plate electrical connection to an electric circuit.