GB623637A - Improvements in or relating to variable resistors particularly for measuring devices - Google Patents

Abstract

623,637. Variable contact resistors. LIQUIDOMETER CORPORATION. Jan. 15, 1946, No. 1355. Convention date, Sept. 24, 1945. [Class 37] [Also in Group XXXVIII] A prime-mover is connected by a linkage to the movable contacts associated with a resistor, so as to effect an amplified electrical displacement of the contacts for a given displacement of the prime-mover. In the embodiments described, movable contacts on an arcuate resistor are given an amplified electrical displacement by a float and linkage arrangement in accordance with changes in liquid level. As shown, Figs. 1, 1a, the linkage 6, 7 causes the movements of float 1 to produce opposite rotations of the contact members 8, 9 about the point 10 and a known form of ratiometer may be energized from the contacts 21 ... 24. In a further embodiment, Fig. 4, a larger degree of amplification is obtained. The two resistor elements 83, 84 are each engaged by contacts on the rotatable members 80, 81, which are connected by the linkage 6, 7 to the float 1. The resistor 83 is energized from the battery 85, and the resistor 84 energized therefrom, in the reverse direction, by the interconnected contacts a ... f and a<SP>1</SP> .. f<SP>1</SP> on the member 81. The contacts 51, 52, 53, carried by the member 80, supply the field coils of potentiometer 89. The resistors 83, 84 may rotate with the member 81, in which case the contacts a ... f and a<SP>1</SP> ... f<SP>1</SP> may be replaced by fixed connections.