Planar coil apparatus for providing a frequency output vs. position
First Claim
1. Apparatus for providing an output signal indicative of a movement between at least a first and second position, comprising:
- (a) a first stationary planar member having disposed on a first surface thereof a flat serpentine coil structure with said coil having output terminals,(b) an oscillator circuit coupled to said output terminal of said coil and operative to provide an output frequency said oscillator including a capacitor which capacitor forms a resonant circuit with said coil to provide said output frequency from said oscillator which frequency varies according to the magnitude of the inductance of said coil,(c) a second movable planar member having disposed on a surface thereof a closed loop coil structure,(d) means for moving said second planar member with respect to said first planar member, modulating the equivalent inductance of said coil structure and to thereby vary the resonant frequency of said oscillator in accordance with the position of said second member with respect to said first member, to cause said oscillator to provide said output frequency which varies monotonically and continuously in accordance with the position of said second member with respect to said first member.
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Accused Products
Abstract
The position sensor constitutes a fixed planar board having disposed on the surface serpentine coil structures of relatively low resistance and inductance. The coils are driven in a resonance mode which provides a frequency output according to the position of a moving planar member. The second movable planar board has disposed on the surface thereof planar loop coil structures. The second board is moved in proximity to the first board to vary the resonance characteristics of the first coil according to the position of the second board with respect to the fixed board. In this manner the frequency output of the system is a function of the position of the boards with respect to one another. Other embodiments depict means for compensating the thermal drifts of the frequency with respect to temperature.
84 Citations
16 Claims
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1. Apparatus for providing an output signal indicative of a movement between at least a first and second position, comprising:
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(a) a first stationary planar member having disposed on a first surface thereof a flat serpentine coil structure with said coil having output terminals, (b) an oscillator circuit coupled to said output terminal of said coil and operative to provide an output frequency said oscillator including a capacitor which capacitor forms a resonant circuit with said coil to provide said output frequency from said oscillator which frequency varies according to the magnitude of the inductance of said coil, (c) a second movable planar member having disposed on a surface thereof a closed loop coil structure, (d) means for moving said second planar member with respect to said first planar member, modulating the equivalent inductance of said coil structure and to thereby vary the resonant frequency of said oscillator in accordance with the position of said second member with respect to said first member, to cause said oscillator to provide said output frequency which varies monotonically and continuously in accordance with the position of said second member with respect to said first member. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification