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. 23, 1990
Filed:
Jun. 01, 1988
Philippe LeMaitre, Grenoble, FR;
Philippe Schuster, Grenoble, FR;
Christian Pellegrin, Grenoble, FR;
Merlin Gerin, , FR;
Abstract
An insulation monitoring device comprises an input circuit of a reference AC signal, and an electronic detection circuit for discriminating the components of a measurement signal proportional to the ground fault impedance Z formed by a leakage resistor Rf in parallel with a leakage capacitor C. A synchronous detector has a pair of static inverters processing the first component, which is a function of the current IR flowing through the leakage resistor Rf, and of the second component which is a function of the current IC flowing through the capacitor C. A converter cooperates with the generator to deliver two quadrature signals C1 and C2 to respectively control the inverters. A display means accurately displays the value of the leakage resistance Rf.