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:
Sep. 17, 2002
Filed:
Jan. 19, 2000
Xiqing Ma, Olathe, KS (US);
Prabhaharan Kumarakulasingam, Lawrence, KS (US);
John M. Donnelly, Overland Park, KS (US);
Arthur David Womack, Jr., Olathe, KS (US);
Mark Stephen Bartrum, Shawnee, KS (US);
SOR, Inc., Lenexa, KS (US);
Abstract
A process control instruments includes a sensor for sensing a process variable in a processing environment, and a switch, a gauge, and a transmitter. The sensor, switch, gauge, and transmitter, a controller to which each of the stated and related components are connected, are powered via a two-wire power loop. In particular, the two-wired power loop also comprises the transmitter, such that the controller, upon receiving information indicative of the level of a variable being sensed by the sensor, modulates the amplitude of the current on the two-wire loop to a level corresponding to the level of the processed variables sensed. Each of the switch, gauge, and transmitter are independently scalable. In the preferred embodiment of the invention, a pair of switches in the form of relays are provided, and a logic circuit operates to power the components of the invention, with the exception of the relays, when the process variable being sensed with within a selected range. When, however, the process variable being sensed dips below the lower threshold(s) or rises above an upper threshold(s), the logic circuit operates to provide power to the components of the invention through a relay corresponding to the threshold reached.