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:
May. 10, 2016
Filed:
Aug. 28, 2013
Applicant:
Fisher Controls International Llc, Marshalltown, IA (US);
Inventor:
Clyde T. Eisenbeis, Marshalltown, IA (US);
Assignee:
FISHER CONTROLS INTERNATIONAL LLC, Marshalltown, IA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H 9/04 (2006.01); H02J 3/00 (2006.01); H02J 9/00 (2006.01);
U.S. Cl.
CPC ...
H02H 9/04 (2013.01); H02J 3/006 (2013.01); H02J 9/00 (2013.01);
Abstract
A protective circuit for a process control device such as a valve actuator, for example, prevents damage to device components. In particular, a protective circuit allows an analog current loop (e.g., 4-20 mA) to provide to a device component a secondary operating voltage, derived from the analog current loop, in the absence of a primary operating voltage source (e.g., during a power failure), such that the device component is not damaged when a signal from the analog current loop is applied to the process control device in the absence of the primary operating voltage source.