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:
Jul. 12, 1983
Filed:
Apr. 23, 1980
Applicant:
Inventor:
Clyde Gilker, S. Milwaukee, WI (US);
Assignee:
McGraw-Edison Company, Rolling Meadows, IL (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361 97 ; 361 93 ;
Abstract
An overcurrent relay circuit has a power supply developed from a test signal representative of the current in the line being monitored. The power supply is a Zener diode and capacitor arrangement connected in series with the load or test resistor. A variable time-current characteristic circuit (or timing plug) is based upon a variable effective capacitance circuit in which the timing capacitor and resistor currents are isolated from, but dependent upon, one another.