The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 05, 1988
Filed:
Jun. 12, 1987
Arthur Baumann, Bertschikon, CH;
Mettler Instrumente AG, Greifensee, CH;
Abstract
Weighing apparatus of the electromagnetic load compensation type includes an improved variable (C.sub.x) and reference (C.sub.o) capacitance comparison arrangement for sensing the position of the movable load receiver member relative to the stationary base member. The comparison arrangement supplies an error signal that is proportional to the capacity ratio, which error is used to control a compensation current (i.sub.L) that is supplied to a compensation coil to maintain the movable load receiver member at its initial zero position. The variable capacitance is produced by a variable air capacitor including a first pair of stationary capacitor plate electrodes (10, 12), and a movable plate-like metal shield or screen which extends partially between the first pair of electrodes in accordance with movement of the load receiver member. The position sensor arrangement is simple to construct and install, and affords precise measurement during use. All of the plate-like capacitor electrodes are stationary, and can be mounted in the immediate vicinity of the error signal generator.