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:
Dec. 01, 1987
Filed:
May. 28, 1986
Applicant:
Inventors:
Pierre O Doittau, Villiers St Frederic, FR;
Herve Moal, Velizy, FR;
Assignee:
Matra, Paris, FR;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
307115 ; 3071 / ; 3071 / ; 307143 ; 307571 ; 3241 / ; 361 86 ; 361 88 ;
Abstract
A device for monitoring the state of a relay comprises an electrical insulation transformer whose secondary winding is connected, through a rectifier, to the output terminals of the relay. The primary winding of the transformer is in series with an oscillator having an impedance greater than that of the primary winding when the relay is closed. A transistor receives a signal from the primary winding and delivers an on-off output signal representing the impedance across the terminals of the relay.