An apparatus, comprising: a rotor configured to rotate about a central axis, said rotor having a first diameter; a first plurality of rod shaped electrodes ( 32, 34) fixedly attached to said rotor, wherein each rod thereof is parallel to all other rods thereof and to said central axis and has a first end and a second end, wherein each said first end is fixedly connected to a first support ring and each said second end is fixedly connected to a second support ring; a first stator and a second stator, wherein said first stator has a second diameter and is centered on said central axis, wherein said second stator has a third diameter and is centered on said central axis, wherein said second diameter and said third diameter are equal, wherein said first diameter is different than both said second diameter and said third diameter; a second plurality of rod shaped electrodes ( 22, 26) fixedly attached to said first stator; a third plurality of rod shaped electrodes ( 24, 28) fixedly attached to said second stator, wherein said first plurality of rod shaped electrodes ( 32, 34) together with said second plurality of rod shaped electrodes ( 22, 26) form a first variable capacitor, wherein said first plurality of rod shaped electrodes ( 32, 34) together with said third plurality of rod shaped electrodes (24, 28) form a second variable capacitor; and a pulse drive circuit connected to said second plurality of rod shaped electrodes (22, 26) and said third plurality of rod shaped electrodes (24, 28); the apparatus being characterized in that it further comprises a magnetic locating system having: a ferromagnetic strip configured as a ring and fixedly connected to said rotor and further having a wave-like edge extending away from said rotor; and a permanent magnet having a pole spaced from said wave-like edge such that when said rotor rotates, the gap between said pole and said wavelike edge varies. a rotor configured to rotate about a central axis, said rotor having a first diameter; a first plurality of rod shaped electrodes ( 32, 34) fixedly attached to said rotor, wherein each rod thereof is parallel to all other rods thereof and to said central axis and has a first end and a second end, wherein each said first end is fixedly connected to a first support ring and each said second end is fixedly connected to a second support ring; a first stator and a second stator, wherein said first stator has a second diameter and is centered on said central axis, wherein said second stator has a third diameter and is centered on said central axis, wherein said second diameter and said third diameter are equal, wherein said first diameter is different than both said second diameter and said third diameter; a second plurality of rod shaped electrodes ( 22, 26) fixedly attached to said first stator; a third plurality of rod shaped electrodes ( 24, 28) fixedly attached to said second stator, wherein said first plurality of rod shaped electrodes ( 32, 34) together with said second plurality of rod shaped electrodes ( 22, 26) form a first variable capacitor, wherein said first plurality of rod shaped electrodes ( 32, 34) together with said third plurality of rod shaped electrodes (24, 28) form a second variable capacitor; and a pulse drive circuit connected to said second plurality of rod shaped electrodes (22, 26) and said third plurality of rod shaped electrodes (24, 28); the apparatus being characterized in that it further comprises a magnetic locating system having: a ferromagnetic strip configured as a ring and fixedly connected to said rotor and further having a wave-like edge extending away from said rotor; and a permanent magnet having a pole spaced from said wave-like edge such that when said rotor rotates, the gap between said pole and said wavelike edge varies. a ferromagnetic strip configured as a ring and fixedly connected to said rotor and further having a wave-like edge extending away from said rotor; and a permanent magnet having a pole spaced from said wave-like edge such that when said rotor rotates, the gap between said pole and said wavelike edge varies.