A rotary position sensor comprising: a) a static portion comprising a first board and a second board; and b) a rotatable portion comprising a third board; and wherein said second board comprises a first planar coil; and wherein said third board comprises a second planar coil and means for generating luminance; and wherein said first board comprises means for receiving said luminance; and wherein said first planar coil of said second board is configured to inductively couple and transmit power to said second planar coil of said third board via inductance; and wherein said power received by said second planar coil is configured to supply a current to said means for generating luminance; and wherein said means for generating luminance is configured to emit a luminance signal which has a luminance level and wherein said means for receiving said luminance is configured to receive and measure said luminance level, and wherein a degree of inductive coupling between said first planar coil of said second board and said second planar coil of said third board varies with an angle of rotation of said third board such that.said luminance level is directly related to said angle of rotation of said third board, a) a static portion comprising a first board and a second board; and b) a rotatable portion comprising a third board; and wherein said second board comprises a first planar coil; and wherein said third board comprises a second planar coil and means for generating luminance; and wherein said first board comprises means for receiving said luminance; and wherein said first planar coil of said second board is configured to inductively couple and transmit power to said second planar coil of said third board via inductance; and wherein said power received by said second planar coil is configured to supply a current to said means for generating luminance; and wherein said means for generating luminance is configured to emit a luminance signal which has a luminance level and wherein said means for receiving said luminance is configured to receive and measure said luminance level, and wherein a degree of inductive coupling between said first planar coil of said second board and said second planar coil of said third board varies with an angle of rotation of said third board such that.said luminance level is directly related to said angle of rotation of said third board, wherein said second board comprises a first planar coil; and wherein said third board comprises a second planar coil and means for generating luminance; and wherein said first board comprises means for receiving said luminance; and wherein said first planar coil of said second board is configured to inductively couple and transmit power to said second planar coil of said third board via inductance; and wherein said power received by said second planar coil is configured to supply a current to said means for generating luminance; and wherein said means for generating luminance is configured to emit a luminance signal which has a luminance level and wherein said means for receiving said luminance is configured to receive and measure said luminance level, and wherein a degree of inductive coupling between said first planar coil of said second board and said second planar coil of said third board varies with an angle of rotation of said third board such that.said luminance level is directly related to said angle of rotation of said third board,