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:
Dec. 27, 2016
Filed:
Apr. 15, 2016
Novelis Inc., Atlanta, GA (US);
Gary Thornton, Fort Collins, CO (US);
Novelis Inc., Atlanta, GA (US);
Abstract
Methods and apparatus for measuring the cleanliness of molten metals. Direct current is passed between electrodes through molten metal advancing through a passage in an electrically resistive wall. A voltage signal is analyzed for the presence of solid generally non-metallic inclusions in the metal. Direct current is supplied by one or more ultra-capacitors and the decay in discharge voltage of the capacitor(s) is compensated for by passing the current from each capacitor through a resistor ladder network circuit having resistors connected in parallel. Individual resistors are switched on or off in a sequence effective to change the resistance of the circuit and maintain the current within a predetermined range. Heat generation and noise pick-up are minimized by maintaining a low discharge voltage and measurement current while using FETs only in the fully ON or OFF conditions to switch the resistors into or out of the circuits.