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:
Apr. 18, 1989
Filed:
Jan. 21, 1988
Applicant:
Inventors:
Richard E Hagerman, Penfield, NY (US);
Joseph F Foster, Fairport, NY (US);
Assignee:
Qualitrol Corporation, Fairport, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361 37 ; 361110 ; 307118 ; 340626 ;
Abstract
An electronic relay control circuit is provided for liquid cooled electric power transformers. The control circuit senses the rate of change of internal tank pressure and operates its relays in response to a sudden pressure increase. Relay control connections are provided for operating transformer trip and annunciator circuits. The relay response is field adjustable.