Abstract: An angle-to-current converter for generating an electrical current output in direct proportion to the degree of angular displacement of an input shaft. The converter includes a differential-inductance transducer constituted by a variable reluctance disc mounted on the input shaft, the profiled edge of the disc passing through diametrically-opposed air gaps defined by the cores of a pair of inductors. The profile of the disc edge is so contoured that as the disc rotates, the region of the edge lying within one gap increases while that lying within the other gap decreases, thereby varying the inductance ratio of the pair as a function of input angle. The transducer inductors are connected to the input of an astable multivibrator in a transmitter wherein the multivibrator generates a square wave whose duty cycle is varied in accordance with the varying inductance ratio and the square wave is integrated to produce a voltage whose magnitude is proportional to the input angle.

Abstract: A variable-area flowmeter system adapted to produce a pneumatic output indication that is linearly proportional to flow rate. The primary of the system includes a float contained in a variable area tube through which flows the fluid to be metered, the float being raised or lowered in the tube as a function of flow rate. A bar magnet is physically coupled to the float and moves axially therewith. The secondary of the system includes a rotatable follower magnet magnetically coupled to the bar magnet to convert the axial movement into rotary motion and an edge-profiled input disc mounted on the shaft of the follower magnet whereby the disc rotates in a direction and to an extent depending on flow rate. The profile is designed to afford a linear relationship between input rotation and output pressure.