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. 17, 1996
Filed:
Jun. 07, 1994
Applicant:
Inventors:
Theodore L Johnson, St. Louis Park, MN (US);
Theodore H Schnaare, Chaska, MN (US);
Assignee:
Rosemount Inc., Eden Prairie, MN (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
34031001 ; 34031006 ; 34031003 ; 34031005 ;
Abstract
A transmitter coupled to a control loop which carries a loop current senses a process variable which is transmitted over the loop. Circuitry in the transmitter presents an effective capacitance C.sub.eff to the control loop. The transmitter includes an isolation network coupled between the circuitry and the control loop which prevents discharge of energy stored in capacitance C.sub.eff into the control loop.