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. 08, 1992
Filed:
Dec. 05, 1990
Applicant:
Inventor:
Edward B Learned, Fort Branch, IN (US);
Assignee:
Potter & Brumfield, Inc., Princeton, IN (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361 91 ; 361 56 ; 361100 ;
Abstract
A protective circuit for removing power from a load detects the presence of a control signal which causes electrical power to be delivered to a load, for example, via a controlled switching device such as an electromechanical relay or a solid state relay. The protective circuit also detects the presence of voltage across the load, signifying that the controlled switching device is causing power to be supplied to the load. The protective circuit removes power form the load when there is an absence of control signal and there is voltage across the load, indicating a failure of the controlled switching device.