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:
Jan. 06, 2004
Filed:
Jan. 25, 2002
Applicant:
Inventor:
Paul Dana Wohlfarth, Vernonia, OR (US);
Assignee:
Credence Systems Corporation, Fremont, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01H 4/704 ;
U.S. Cl.
CPC ...
H01H 4/704 ;
Abstract
A relay controller intermittently connects a power supply across a relay coil with a controlled duty cycle whenever the relay coil is to generate a magnetic field for opening or closing the relay's contacts. The duty cycle with which the controller connects the power supply across the coil controls limits a steady-state amplitude of current passing through the coil, thereby controlling the intensity of the magnetic field the coil generates.