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.

Date of Patent:
May. 27, 2003

Filed:

Dec. 30, 1997
Applicant:
Inventor:

Martin Malenfant, Chambly, CA;

Assignee:

Gelcore LLC, Valley View, OH (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G08B 2/100 ;
U.S. Cl.
CPC ...
G08B 2/100 ;
Abstract

In a light-emitting-diode lamp, there is provided an input impedance-changing circuit for establishing a low input impedance circuit when the light-emitting-diode lamp is missingline turned off. This input impedance-changing circuiting comprises Shunt circuit section, and a detector circuit section. The shunt circuit section includes a low impedance element and a controllable switching device connected in series. The detector circuit section detects turning off of the light-emitting-diode lamp and, in response to such detection, close the switching device to thereby cause electric current to flow through the shunt circuit section in order to simulate lower input impedance of the light-emitting-diode lamp. When the light-emitting-diode lamp replaces a conventional traffic signal incandescent lamp, the input impedance-changing circuitry prevents the conflict monitor of the already installed traffic-light lamp system to detect a high lamp impedance and accordingly a faulty lamp.


Find Patent Forward Citations

Malenfant, Martin. (2003). Led lamp with a fault-indicating impedance-changing circuit (U.S. Patent No. 6570505). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/6570505

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

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