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. 25, 1995
Filed:
Dec. 10, 1992
Bruce D Royner, Eden Prairie, MN (US);
Thomas P Coursolle, St. Paul, MN (US);
Rosemount Inc., Eden Prairie, MN (US);
Abstract
An AC powered field mounted process control transmitter includes an inrush current limiter which prevents excessive current flow to other circuitry in the transmitter. The transmitter senses a physical parameter, such as flow, and comprises a source of current, a current driven sensing circuitry, the inrush current limiter and measurement electronics for converting the sensed parameter into a transmitter output. The limiter includes a reference voltage source and is in series between the current source and the current driven sensing circuitry. When inactive (i.e. not limiting current), the limiter responds to the series current through itself so that when such current exceeds a predetermined maximum level the limiter becomes active and prevents further current flow. The limiter remains active until the voltage across itself is less than the reference voltage, at which time the limiter becomes inactive.