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. 24, 2013
Filed:
Dec. 16, 2008
Applicant:
Zhen Liu, Houston, TX (US);
Inventor:
Zhen Liu, Houston, TX (US);
Assignee:
Hydril USA Manfacturing LLC, Houston, TX (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01B 7/14 (2006.01);
U.S. Cl.
CPC ...
Abstract
A solenoid current monitoring circuit of a solenoid actuator includes a solenoid drive board configured to receive a control signal, a sensing resistor configured to detect a current signal of a solenoid coil of the actuator resulting from the control signal, and a differentiator configured to differentiate the current signal. The solenoid current monitoring circuit detects the movement of the solenoid actuator based on a change in the differentiated current signal caused by a change in inductance of the solenoid coil.