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:
Feb. 27, 2007
Filed:
Mar. 23, 2005
Robert J. Alvord, Elmwood Park, IL (US);
Robert J. Alvord, Elmwood Park, IL (US);
Robertshaw Controls Company, Richmond, VA (US);
Abstract
A diagnostic circuit is provided. The diagnostic circuit comprises resistors and a capacitor. The diagnostic circuit is monitored to detect the presence of a load and to confirm the proper operation of a relay circuit. The diagnostic circuit generates an oscillating voltage when the relay circuit is open and the load is connected, generates a logic low when the relay circuit is open and the load is disconnected, and generates a logic high when the relay circuit is closed. The diagnostic circuit can be disposed within a diagnostic circuit system that includes one or more of a sensing circuit, a relay circuit, an alternating-current source having a direct current offset, an input circuit, and a high-voltage microprocessor. The high-voltage microprocessor can be bi-directionally optically coupled to an application microprocessor.