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:
Mar. 26, 2019
Filed:
Feb. 16, 2017
Mettler-toledo Gmbh, Greifensee, CH;
Mettler-Toledo GmbH, Greifensee, CH;
Abstract
A differential measurement circuit () is implemented in a balance with electromagnetic force compensation. The circuit receives input from two photo currents (I, I) generated by photodiodes (D, D) and generates an output signal proportional to their difference. A switch (SW) controls the flow of current through a node (K) to which the two photo currents are directed, by flipping between two states (z, z) within two phases (t, t) of a time period T. The switch is controlled so a reference current (I) from a voltage or current source (U) is superimposed alternatingly within the time phases on one of the two photo currents which continuously flow into the node. The node lies at the input of an integrator (INT) whose integrator signal (s) can be compared in a comparator (CMP) to a cyclically recurring ramp signal (s) which conforms to the time period. At the output of the comparator, a rectangular-shaped comparator signal (s) can be generated whose duty cycle ratio is defined by the intersection of the integrator signal with the ramp signal and which can be directed to a control input of the switch.